BENDING BEHAVIOR OF COMPOSITE FERRO- CEMENT SLABS IN …

BENDING BEHAVIOR OF COMPOSITE FERRO-

CEMENT SLABS IN COLD FORMED STEEL FLOORS

By

Adham Elsayed Zakaria Tonsy

A Thesis Submitted to the

Faculty of Engineering at Cairo University

in Partial Fulfillment of the Requirements for the degree of

MASTER OF SCIENCE

In

Structural Engineering

FACULTY OF ENGINEERING, CAIRO UNIVERSITY

GIZA, EGYPT

2018

BENDING BEHAVIOR OF COMPOSITE FERROCEMENT

SLABS IN COLD FORMED STEEL FLOORS

By





MASTER OF SCIENCE

In


Under the Supervision of

Prof. Dr. Metwally Abu-Hamd

…………………………..

Professor of Steel Structures and Bridges

Structural Engineering Department

Faculty of Engineering

Cairo University

Prof. Dr. Sameh Youssef Mahfouz

Yassin

…………………………

Associate Professor of Steel Structures

Head of Construction and Building

Engineering Department

Arab Academy for Science, Technology

and Maritime Transport


GIZA, EGYPT

2018

BENDING BEHAVIOR OF COMPOSITE FERROCEMENT

SLABS IN COLD FORMED STEEL FLOORS

By





MASTER OF SCIENCE

In


Approved by the

Examining Committee:

Prof. Dr.

Prof. Dr.

Prof. Dr.


GIZA, EGYPT

2018

Engineer`s Name:

Date of Birth:

Nationality:

E-mail:

Phone:

Address:

Registration date:

Awarding date:

Degree:

Department:

Supervisors:

Examiners:


20/07/1991

Egyptian

[email protected]

+201007140019

508 Nargess buildings, 5th settlement

01/03/2014

.../…/2018

Master of Science

Structural engineering

Prof. Dr. Metwally Abu-hamd

Prof. Dr. Sameh Youssef Mahfouz Yassin

Prof. Dr.

Prof. Dr.

Prof. Dr.

Title of Thesis:

Bending behavior of composite Ferro-cement slabs in cold formed steel floors

Keywords:

Ferro-cement slabs, shear connector, CFS section, and wire mesh

mailto:[email protected]

i

ACKNOWLEDGEMENTS

First and foremost I would like express my thanks to Almighty ALLAH on successful

completion of this research work and thesis

I hereby, express my sincere and profound gratitude to my supervisors Professor Dr.

Metwally Abu-hamd and professor Dr. Sameh Youssef Mahfouz for their continuing

assistance, support, guidance, and understanding throughout my graduate studies. Their trust,

patience, knowledge, great insight, modesty and friendly personality have always been an

inspiration for me and will deeply influence my career and future life.

The author is grateful Faculty of Civil Engineering, Cairo University for their support,

assistance and friendly treatment that not only facilitated the work, but also made it pleasant.

I also wish to express my deep gratitude to my friends in Egypt and for their invaluable

support and encouragement through the years. Special thanks are due to last but not the least

my heartiest appreciation goes to my parents for their endless patience and understanding

towards my work and everlasting love.

ii

TABLE OF CONTENTS

ACKNOWLEDGEMENT………………...……..….………...…….……..……………….I

TABLE OF CONTENTS ………...……………….…….....….………….………….........II

LIST OF FIGURES …………..……………………..……….………………....…......…V

LIST OF TABLES ……………………..……………………….……….…..................VII

ABSTRACT……………………………….………………………..………..………VIII

Chapter One: Introduction .................................................................................... 1

1.1 General Appraisal: ...................................................................................... 1

1.2 Problem Statement ...................................................................................... 3

1.3 Aim and Objectives .................................................................................... 3

1.4 CFS-Ferro-cement Composite Slab Tests .................................................... 4

1.5 Thesis Layout ............................................................................................. 4

Chapter Two: Literature Review .......................................................................... 6

2.1 Introduction ................................................................................................ 6

2.2 Ferro-cement............................................................................................... 6

2.2.1 Ferro-cement Versus Reinforced Concrete (Distinct Characteristics).... 6

2.2.2 Ferro-cement as a Laminated Composite .............................................. 7

2.2.3 Mechanical Properties of Ferro-cement ................................................ 8

2.2.4 Durability ........................................................................................... 14

2.3 Cold-Formed Steel Structures ................................................................... 15

2.3.1 Cold-Formed Steel Beams .................................................................. 15

2.3.2 Structural Behavior - Modes of Failure Due To Bending Buckling ..... 16

2.4 Shear Connectors ...................................................................................... 20

2.5 Review of Previous Investigations on Ferro-cement slab .......................... 21

2.6 Summary .................................................................................................. 23

Chapter Three: Experimental Work .................................................................... 24

iii

3.1 General Research Outline ......................................................................... 24

3.2 Materials ................................................................................................... 24

3.2.1 Cement ............................................................................................... 24

3.2.2 Fine aggregate .................................................................................... 24

3.2.3 Water ................................................................................................. 26

3.2.4 Wire Meshes ...................................................................................... 26

3.2.5 Mortar ................................................................................................ 26

3.2.6 Cold formed steel section ................................................................... 27

3.2.7 Shear connector .................................................................................. 27

3.2.8 Mortar Compressive Strength Test ..................................................... 27

3.3 Full-Scale Flexural Test ............................................................................ 29

3.4 Test Specimens and Arrangement ............................................................. 30

3.5 Test Procedures......................................................................................... 35

Chapter Four: Results and Discussion ................................................................ 37

4.1 Introduction .............................................................................................. 37

4.2 CFS-Ferro-cement composite slab behavior .............................................. 37

4.2.1 Group 1 .............................................................................................. 38

4.2.2 Group 2 .............................................................................................. 46

4.2.3 Strain analysis .................................................................................... 56

4.3 Parameters Studied ................................................................................... 66

4.3.1 Effect of Increasing the Slab Thickness .............................................. 66

4.3.2 Effect of increasing the number of Bolts Connecting the Ferro-cement

slab with the CFS-Section ................................................................................. 71

Chapter Five: Conclusions and Recommendations ............................................. 74

5.1 Strength and Stiffness of Composite Slabs ................................................ 74

iv

5.2 Recommendations ..................................................................................... 75

References……………………………………….……………………………….76

v

LIST OF FIGURES

Figure 1-1: Typical CFS sections ............................................................................... 2

Figure 2-1: Ferro-cement versus reinforced concrete (cross sections) (Naaman, 2000)

................................................................................................................................... 7

Figure 2-2: Ferro-cement as laminated composite (Naaman, 2000) ........................... 8

Figure 2-3: Schematic load-elongation curve of reinforcement concrete and Ferro-

cement in tension (Naaman, 2000) .............................................................................. 9

Figure 2-4: Typical qualitative influence of specific surface of reinforcement on

properties of Ferro-cement (Naaman, 2000) ............................................................. 10

Figure 2-5: Typical load deflection response of Ferro-cement illustrating various

stages of behavior (Naaman, 2000) .......................................................................... 12

Figure 2-6: Load versus various mesh layers of Ferro-cement in flexure (Arif et al.,

1999) ........................................................................................................................ 13

Figure 2-7: Cold-formed symmetrical I-sections: (a) two channels using bolts: (b)

Section using clamps (Hsu et al., 2003) .................................................................... 16

Figure 2-8: Modes of buckling of lipped channel in bending (Yu, 2001) ................... 17

Figure 2-9: Lateral buckling of an I-section beam (Rhodes, 1991) ........................... 20

Figure 2-10: Deflection history of I beam due to lateral buckling (Yu, 2001) ........... 20

Figure 3-1 Fine aggregate grading curve ................................................................. 25

Figure 3-2 the photographic view of wire mesh ........................................................ 26

Figure 3-3 Cold- formed lipped channel steel sections ............................................. 27

Figure 3-4 the cube compressive strength testing set up. .......................................... 28

Figure 3-5 layout of CFS-Ferro-cement composite slab specimen ........................... 32

Figure 3-6 Preparation of the composite Ferro-cement slab specimen ..................... 34

Figure 3-7 Dial gauges arrangement in the specimen ............................................... 34

Figure 3-8 testing up of the tests for all specimens ................................................... 35

Figure 3-9 Restrain the CFS sections at both ends to prevent lateral bucking .......... 36

Figure 4-1 CFS Ferro-cement composite slab .......................................................... 37

Figure 4-2 Load versus mid span deflection for Group 1 specimens ......................... 44

vi

Figure 4-3 Large deflection at the middle of the beam .............................................. 45

Figure 4-4 Transverse and longitudinal cracks ......................................................... 46

Figure 4-5 Load versus mid span deflection for Group 2 specimens ......................... 54

Figure 4-6 Large deflection at the middle of the beam .............................................. 55

Figure 4-7 Transverse and longitudinal cracks ......................................................... 55

Figure 4-8 load against strain at critical cross-section of the composite slabs for all

CFS-Ferro-cement composite slab specimens ........................................................... 65

Figure 4-9 mid span load-deflection curves of Ferro-cement slab for partially

composite specimens................................................................................................. 66

Figure 4-10 mid span load-deflection curves of CFS beams for partially composite

specimens ................................................................................................................. 68

Figure 4-11 mid span load-deflection curves of Ferro-cement slab for fully composite

specimens ................................................................................................................. 68

Figure 4-12 mid span load-deflection curves of CFS beams for fully composite

specimens ................................................................................................................. 70

vii

LIST OF TABLES

Table 3-1 Initial and final settings of cement ............................................................ 24

Table 3-2 Sieve analysis test results .......................................................................... 25

Table 3-3 Fineness modulus, moisture content and % of clay and fine materials ...... 25

Table 3-4 the results of the material test of mortar ................................................... 29

Table 3-5 Details description of composite slabs specimens ..................................... 31

Table 4-1 Experimental results of full scale composite slab testing ........................... 38

Table 4-2 the values of strain at ultimate load for all CFS sections .......................... 56

Table 4-3 the mid span ultimate strain values for CFS beams ................................... 70

Table 4-3 the ultimate loads of tested specimens ....................................................... 71

Table 4-4 the mid span deflections for CFS beams and Ferro-cement slab ............... 72

Table 4-5 the mid span strain values for CFS beams ................................................ 73

viii

ABSTRACT

This study investigates the structural behavior of continuously supported composite

Ferro-cement slabs, in which a Ferro-cement slab is connected together with cold-formed

steel (CFS) beam by means of shear connectors. This system, called a Precast Cold- Formed

Steel-Ferro-cement Composite Slab System, is designed to produce the composite action

between the CFS structure and Ferro-cement slab where shear forces are transmitted between

the beam and slab through shear connectors or studs. Ferro-cement slabs can be defined as a

thin reinforced concrete structure in which a brittle mortar is reinforced with layers of thin

wire mesh, uniformly dispersed throughout the matrix of the composite section. This research

is based on Experimental works involved full-scale testing of laboratory tests consisted of a

total of nine full-scale continuously supported composite Ferro-cement slabs with different

parameters and tested to fracture. One type of shear connectors (bolts) was tested and one

layer of wire mesh in Ferro-cement cold formed was proposed. The main variables

considered in the study are thickness (30mm, 40mm) of the Ferro-cement slab and different

spacing between bolts (450mm, 150mm).Uniform load bending system was used to test the

specimens. The results confirmed that increasing the thickness of Ferro-cement slab has not

significantly increased the load capacity of the composite slab. However, the increase in slab

thickness has delayed the formation of cracks at an early stage. Also, using spacing between

bolts (150 mm) has increased the capacity load of the fully composite section by almost one

third the capacity load of the partially composite section (Spacing 450 mm).

1

Chapter One: Introduction

1.1 General Appraisal:

Using composite slabs, to improve the stiffness and the load capacity of the slab, become

more popular in the building industry. The composite slab has resulted in great savings in the

weight of steel structure and reduction in beam depth. For more economical section, cold-

formed steel sections interact with the Ferro-cement slab through shear connectors.

(Deierlein, 1988; Viestetet al., 1997)

The advantages of composite construction have been widely spread due to the use of

Ferro-cement as a pre-cast composite slab. Composite action depends on interactive behavior

between steel section and concrete components designed together to be more efficient in

resisting the applied loads.

The interaction between steel and concrete in the composite structure was as following;

the upper compressive force was carried by the concrete slab and the lower tensile force was

carried through the tensile resistance of the steel section. The interaction between the

concrete slab and the steel beam is provided through shear studs to resist the shear flow at the

interface of the two materials.

Welding of shear studs is not applicable due to the relatively small thickness of the cold

formed sections (Hanaor, 2008); so, the shear connection between CFS and concrete must be

investigated and need more research.

The manufacturing of cold formed steel section is carried out at room temperature,

through rolling up a steel sheet of thickness from 1.5 mm to 4 mm. The use of CFS section in

the building industry started in the 1850s in both the United States of America (USA) and

Great Britain (UK). The CFS structural sections have many advantages than hot-rolled

sections, such as small thickness, lightness, ease of prefabrication, fast erection, and

installation.

One of the established commercial applications between CFS and concrete is the

composite slab system, where a concrete layer is placed on top of CFS section. However, the

structural use of CFS sections began in the mid of 20th century especially for industrial and

commercial buildings (Hancock et al., 2001). The typical sections widely used as purlins and

truss members are "Z" and "lipped C" sections (Figure 1.1).

2

Figure 1-1: Typical CFS sections

Composite construction of CFS sections and concrete began in Europe since 1940 and

was mainly used for roof systems, where a metal deck made from CFS was used to act

compositely with concrete (Sabnis, 1979).

Ferro-cement slabs can be defined as a thin reinforced concrete structure in which a

brittle mortar is reinforced with layers of thin wire mesh, uniformly dispersed throughout the

matrix of the composite section (Naaman, 2000). Ferro-cement slabs have taken a significant

place between the construction elements for its mechanical and durability properties which

recommend it the most suitable system for lightweight structures. Ferro-cement slabs

consider being an economic and suitable alternative material for roofing; however flat or

corrugated roofing system is quite popular.

This study investigated the structural behavior of composite slab system with CFS as

beam and Ferro-cement as slab. This type of system could solve the problem of a low rupture

bending capacity of the Ferro-cement slab. The proposed composite slab system improves the

rupture bending capacity and reduces the deflection due to the composite action and also

speeds up the construction time as the proposed Ferro-cement slab acts as permanent

formwork.

3

1.2 Problem Statement

Over the years, Ferro-cement slabs applications have widely increased due to its

mechanical and durability properties such as strength, toughness, lightness, and ductility. The

wide spread of Ferro-cement slab in the construction industry is due to relatively low cost,

weight and the ease of the production.

Although CFS slabs system is considered one of the most important construction element

as a sustainable structures in the developed countries have been recognized as an important

contributor to sustainable structures in the developed countries (Yu et al., 2005), its

application is limited to roofing systems and non-structural applications (Shaari & Ismail,

2003). This can be attributed to the small thickness of its cross-section that makes it easily

subjected to torsion failure, distortional, lateral torsional, lateral distortional and local

buckling

Pre- fabricated Ferro-cement slabs is widely used in the developed countries as mention

before. It considered one of the best alternatives in the construction industry to overcome the

high cost of the other building systems, and ease of erection which reduce the time of the

construction period and to get better quality control.

In this study, a type of composite slab comprised of CFS section with Ferro-cement

called Precast Cold–Formed Steel-Ferro-cement Composite slab System is proposed to

reduce the weight as well as to improve the strength of the composite system. One of the

main advantages of this system is its light weight compared to normal reinforced concrete

slab which results in the reduction of loads transmitted to supported elements.

1.3 Aim and Objectives

The aim of this research is to the properties of a precast proposed Ferro-cement-CFS

composite slab structural system. To achieve this aim, the following objectives are studied:

1. To investigate the different parameters that controls the performance of the

proposed composite slab system.

2. To study the behavior and performance of proposed Ferro-cement slab CFS as

composite slab system.

4

1.4 CFS-Ferro-cement Composite Slab Tests

The beam section consists of one lipped channel. The flanges were connected with Ferro-

cement panel by one type of shear connector (Bolts). The proposed CFS-Ferro-cement

composite slabs were tested as full scale and their results were used to evaluate the behavior and

performance of Ferro-cement slab connected to CFS By means of shear connector. There were

nine specimens with different configurations prepared for full-scale testing. A full-scale of

continuously supported slab specimens was tested using uniform load system.

Hence, the ultimate flexural capacity of the proposed composite slabs can be established.

Details of specimen’s description and parameters studied are discussed in Chapter 3. The

results and discussion of the experimental tests are discussed in chapter 4.

The finding from this research may eventually lead to the development or improvement

of the existing system on the welding problem of shear studs on CFS due to its thinness.

Therefore, this research is to investigate the possibility of using CFS-Ferro-cement composite

slabs for structures.

The outcome of this research contributes to promote the proposed composite slab

construction method as possible industry implementation and also the use of CFS as one of

the alternative materials for small to medium size building construction. Also this research

provides important technical knowledge which can be used as a design guideline for the

proposed composite slab of CFS and Ferro-cement structures.

1.5 Thesis Layout

Chapter one presents the general introduction, background of the study, problem

statement, aims and objectives and scope of this research. Significance of the study and thesis

layout is also described in this chapter.

Chapter two carries a comprehensive literature review on the area of study and all

published works related to current study.

Chapter three describes the specimen, test setup and full-scale flexural test of CFS-

Ferro-cement composite slabs.

5

Chapter four describes the results and analysis of the full-scale flexural test of CFS-

Ferro-cement composite slabs.

Chapter five presents the discussion and comparison of all the test results, conclusions

and the recommendations.

6

Chapter Two: Literature Review

2.1 Introduction

In this chapter, a review on composite slab with CFS section and the advantages of

Ferro-cement are presented. The importance and advantages of composite construction

are also highlighted. Three main components of composite slab i.e. Ferro-cement slab,

steel beam and shear connectors or studs are illustrated. Previous works related to

composite slab with CFS section and Ferro-cement member are presented.

2.2 Ferro-cement

Ferro-cement slabs can be considered one of the react innovated construction

building systems. Ferro-cement slabs is characterized of its thin thickness i.e. nearly 3

or 4 mm and its cross-section composed of light weight cement mortar and reinforced

with a densely wired mesh (Naaman, 2000). One of the main advantages of Ferro-

cement slabs that it can be easily molded in any shape due to its highly mold ability.

Due to the high magnitude of the specific surface of reinforcement in Ferro-cement

slabs, a higher bond between the mesh reinforcement and the cement matrix was

offered (Naaman, 2000).

The close spacing of the wire meshes in cement mortar improves ductility, and

leads to a better crack pattern mechanism in Ferro-cement (Kumar, 2005). The

applications of Ferro-cement are huge including low-cost roofing on short spans

(Kumar, 2005), repair and rehabilitation of deteriorated structures (Wang et al., 2004;

Ibrahim, 2011).

2.2.1 Ferro-cement Versus Reinforced Concrete (Distinct

Characteristics)

Ferro-cement is a kind of reinforced concrete construction, however, it is quite

different based on some significant factors which are adequately enough to elucidate

the variance. Compared to reinforced concrete, Ferro-cement (Figure 2.1):

7

More thin. Distributed reinforcement.

doubly reinforced in both longitudinal and transverse directions

Consists of fine mortar or paste matrix compared to concrete

with longer aggregates.

Figure 2-1: Ferro-cement versus reinforced concrete (cross sections) (Naaman, 2000)

2.2.2 Ferro-cement as a Laminated Composite

A lamina is assumed to be a composite made of single layer of mesh embedded in a

layer of cement mortar. Thus Ferro-cement can be considered as a laminated composite.

A lamina has orthotropic properties, i.e., its mechanical properties are different in the

three principal directions. In Ferro-cement if it is reinforced with square mesh, it will

have identical properties in the two principal directions. Figure 2.2 shows Ferro-cement

viewed as a laminated composite.

8

Figure 2-2: Ferro-cement as laminated composite (Naaman, 2000)

2.2.3 Mechanical Properties of Ferro-cement

The distinctive properties of Ferro-cement emanate from the substantial quantity of

two-way reinforcement which consists of smaller members having bigger surface area

than normal reinforcement. The term Ferro-cement was firstly used by Nervi (ACI

549R, 1997). According to him, the most notable features of Ferro-cement are “greater

resistance to cracking and elasticity”.

2.2.3.1 Tensile Strength

Ferro-cement is a material with a variety of unique properties. It is a miniature

model of a high performance reinforced concrete; when it cracks under service loads,

the crack is visible. Figure 2.3 (a) illustrates the load-deflection curve of a typical

reinforced concrete testing prism. The tensile stress-strain response of the reinforcing

steel is assumed to be elastic perfectly plastic (Naaman, 2000). Several stages of

behavior can be identified:

I. Stage I corresponds to the ascending linear static portion of the curve (OA);

this portion leads to a small plateau region which corresponds to cracking

of the prism.

9

II. Stage II corresponds to the portion of the curve (AB) where cracking starts

and during which crack formation stabilizes; generally, most cracks are

formed within a relatively small increment of load beyond first structural

cracking.

III. Stage III (BC) where the load-elongation response is most linear elastic and

crack widths increase with an increase in applied load; because of cracking,

the slope of this portion of the curve is smaller than that of the initial

portion. Stage III extends until the reinforcing steel yields.

Beyond yielding, represented by point C, the curve is essentially similar to that of

the reinforcing steel and failure will occur when it fails. Figure 2.3 (b) illustrates the

load elongation curve of a typical Ferro-cement tensile prism. The stages identified in

Figure 2.3 (a) for reinforced concrete are also observed here; however, the main

difference is in stage II. In Ferro-cement, stage II (AB) can be so extensive so as to

completely take over stage III. In particular, after first cracking, cracks keep forming

with increasing load. If the reinforcing parameters are appropriate, multiple cracking

can be extensive and at the end of multiple cracking, i.e., when the numbers of cracks

stabilize, they can be near to the yielding point of the steel.

Figure 2-3: Schematic load-elongation curve of reinforcement concrete and Ferro-cement in

tension (Naaman, 2000)

10

The main point when comparing between Ferro-cement and reinforced concrete is

its high specific surface area of reinforcement compared to the traditional

reinforcement.

The high specific surface area of reinforcement for Ferro-cement results in a

different tensile and flexural behavior, as was indicated by the experimental studies. It

was found that the tensile strength of Ferro-cement at first crack is directly proportional

to the specific surface of reinforcement (Swamy and Shaheen, 1990; Arif et al., 1999;

Somayaji and Naaman 1981; Naaman, 2000).

This can also be observed in Figure 2.5 which shows the effect of the specific

surface area of reinforcement on the stress at first crack, the stress at crack saturation,

the ultimate strain of the composite, and the crack width. The tensile strength of Ferro-

cement varies with the orientation of the mesh and the nature of applied loading

(Abdullah and Mansur, 2001; Arif et al., 1999).

Figure 2-4: Typical qualitative influence of specific surface of reinforcement on properties of

Ferro-cement (Naaman, 2000)

11

2.2.3.2 Compressive Strength

The compressive strength of Ferro-cement is controlled by the properties of the

cement mortar mix. Typical compression test results of Ferro-cement cubes suggest that

the compressive strength of Ferro-cement is smaller than that of the matrix alone due to

splitting transverse tensile stresses and buckling of the mesh reinforcement in

compression (Al-Noury and Haq, 1988; Mansur and Abdullah, 1998; Naaman, 2000).

Under normal circumstances, the type of mesh and its orientation also affect the

compressive strength. The performance of expanded and hexagonal metal meshes with

orientation in the direction of loading are lower to that of square wire meshes in the

same orientation. Wire meshes at 45 degrees orientation are also with lesser efficient

compared to meshes aligned along the loading direction (Hossain and Inoue, 2000).

In general, strain-stress plots of Ferro-cement are non-linear; Ferro-cement shows

linearity at 50-60% of the maximum strength while there is non-linearity at initial, in

between and final part of the plot (Hossain and Inoue, 2000; Rao, 1992; Rao and Rao,

1986).

2.2.3.3 Bending (Flexure)

Bending replicates the joint effect of parameters dictating both the tensile and

compression characteristic features, like mortar compressive strength, mesh type, mesh

properties and mesh orientation. However, it is generally presumed that the two way

composition of mesh reinforcement contributes extra strength and safety to one

directional bending.

Analogous to the case of tension, Ferro-cement displays typical features in bending

also. Figure 2.8 typifies load versus deflection response of Ferro-cement in bending.

12

Figure 2-5: Typical load deflection response of Ferro-cement illustrating various stages of

behavior (Naaman, 2000)

Several portions of the curve can be identified:

a) An early part where structural cracking does not occur.

b) A multiple cracking portion where cracks emanate and their width increases

with increasing load.

c) A portion where steady yielding of the steel reinforcement takes place;

gradual yielding occurs even when the steel mesh has a definite yield point,

because several layers of mesh, placed at different depths of the section,

undergo yielding at different loading levels.

d) A post-yielding plastic or strain-hardening region during which the

maximum or ultimate load is attained.

e) A post-peak portion where failure happens due to either mortar failure in

compression or failure of the extreme layer of mesh.

In general, the bending resistance and the flexural moment capacity increase with

the increase in mesh layers. Figure 2.9 shows the load carrying capacity of Ferro-

cement with varying number of mesh layers. However, it is not directly proportional to

the volume fraction of reinforcement.

13

This is because even if intermediate meshes placed near the Centre of the section

undergo yielding, they do not contribute as much as meshes placed near the outer

surfaces (Mansur and Paramasivam, 1986; Mansur, 1988; Bhatacharyya et al., 2003;

Montesinos and Naaman, 2004; Suksawang et al., 2006)

The behavior of plain mortar under bending is replicated by Ferro-cement with

bundled mesh layer at cross-sectional Centre. The most effective stratum of mesh is the

one nearest to the farthest fiber or the face of the element in Ferro-cement bending

elements same as in reinforced concrete (Paramasivam and Ravindarajah, 1988). Unlike

in tension, the particular surface of reinforcement does not have a great control on the

cracking pattern in bending. The average crack width is basically dependent on tensile

strain in the farthest stratum of wire mesh and the spacing of wire mesh in transverse

(Naaman, 2000).

Under normal circumstances, square shaped welded mesh attains better behavioral

performance in bending than mesh of other shapes. This emanates from transverse

wires in welded wire meshes provision of higher anchorage for bond zone through

which the matrix are supported via biaxial confinement. The least performance is from

the hexagonal shaped wire meshes.

The same applies to tension; 45 degree orientation provides the least configuration

in bending (Naaman, 2000; Arif et al., 2001). The influence of mesh orientation on load

carrying capacity of Ferro-cement subjected to bending is shown in Figure 2.9.

Figure 2-6: Load versus various mesh layers of Ferro-cement in flexure (Arif et al., 1999)

14

2.2.3.4 Shear

There is relatively little information on the shear properties of Ferro-cement. This

because Ferro-cement is primarily used in the form of thin elements where the span-to-

depth ratio is large enough that one-way shear does not control the failure mode.

Moreover, parallel longitudinal alignment of the reinforcing layers, and a high volume

fraction of mesh which contributes to the dowel action resistance in shear. Thus, in case

of Ferro-cement beams the behavior is controlled by the bending (Naaman, 2000).

Irrespective of the content and type of used mesh or strength of mortar, it has been

reported that an approximate 32 percent of bending strength is the shear strength

(Mansur and Ong, 1987). In contrast, flexural capacity of Ferro-cement is reached first

before shear failure occurs (Mansur and Ong, 1991). In addition, cracking shear

strength of Ferro-cement varies inversely with the span-to-depth ratio and

proportionally with layers of mesh and strength of mortar (Al-Kubaisy and Nedwell,

1999).

Apart from its exhibition of excellent crack control characteristics in shear, Ferro-

cement slabs behavior is comparable to that of conventional concrete slab. However, in

contrast to the failure of slabs in flexure, the failure of slabs in shear shows only a small

signal of impending failure, except for the creation of a great number of diagonal cracks

and an insignificant plastic behavior after the multiple cracking (Mansur and

Kiritharan,2001; Alsulaimani and Basunbal,1991).

The punching shear strength of slabs subjected to central load, increase with the

increase in width of punching area, volume fraction of mesh reinforcement, depth of

slab, and mortar compressive strength while it decreases with the increase in effective

span and the size of loading area (Paramasivam and Tan, 1993; Ahmed and

Nimityongskul, 1998; Mansur et al., 2001).

2.2.4 Durability

Durability is the ability of Ferro-cement to withstand deteriorations when exposed

to different loading and environmental exposures. There are two unique factors which

determine durability of Ferro-cement apart from those of the normal reinforced

concrete:

15

I. The cover to the mesh reinforcement is comparatively small and

accordingly it is more convenient for corrosive liquids to penetrate to the

reinforcement (Nedwell, 2000; Mansur et. al., 1996).

II. The surface area of the reinforcement is unusually high; so that the contact

area available for corrosion and its subsequent rate are potentially high

(Naaman, 2000).

However, each factor differs in affecting the durability of the Ferro-cement

depending on condition of exposure. Therefore it is very important to provide sufficient

cover to Ferro-cement elements. The armature cover in compressed regions can be as

high as 6 mm, while a minimum of 10 mm has been suggested for medium aggressive

environments (Mansur et al., 1996; Liborio and Hanai, 1992).

For a simulated load-marine corrosion environment, an OPC mortar cover of 5 mm

have been shown to supply adequate barrier for the galvanized weld mesh against

corrosion (Xiong and Singh, 1997).

2.3 Cold-Formed Steel Structures

The contemporary needs of high strength materials for structural purposes brought

about substantial use of CFS manufactured through the bending of horizontal level steel

sheets at controlled temperature. The thickness of CFS sections ranged from 1.2 to

3.2mm (Yu et al., 2005); and they are highly regarded for their roles in sustainable

construction as a green technological material. They were utilized for the erection of

commercial and residential structures as roof trusses and for other non-structural

purposes.

2.3.1 Cold-Formed Steel Beams

Beam is defined as a structural member that acts laterally in response to

longitudinally loads by bending or deflecting along its axis. Upon being loaded, strain

and stresses occurs which leads to determination of shear force and bending moment

capacity.

16

The usual shapes of the CFS section used in structural beams are C-section with or

without lips, Z-sections and I-sections. CFS I-sections are usually formed when two C-

lipped channel sections are oriented back-to-back so that higher moment stability and

bearing performance could be achieved as shown in (Figure 2.10 a). Hsu et al., (2003),

proposed the I-shaped closed loops thin-walled plates into the preferred double

symmetrical geometry that form closed loops. This design philosophy was achieved by

forming the I-section with plate edges clamped at the flange location, (Figure 2.10 b).

However, this type of beam is difficult to form and not practical to be used in

construction.

Figure 2-7: Cold-formed symmetrical I-sections: (a) two channels using bolts: (b) Section

using clamps (Hsu et al., 2003)

2.3.2 Structural Behavior - Modes of Failure Due To Bending

Buckling

There are three basic buckling modes for CFS members such as local buckling,

distortional buckling and lateral or flexural torsional buckling, as shown in Figure 2.11

(Hancock et al.,2001; Cheng and Benjamm, 2003; Hancock, 2003). The transverse

deformation of plate flexure which encompasses distortion of the line of intersection is

known to be local buckling.

17

Lateral torsional buckling happened when the bending members bend or twist from

lateral plan view and remain in the same cross sectional shape. Local shear buckling

takes place in slender webs with bending members in the wide flanges of sheeting

profiles subject to diaphragm action. Global shear buckling occurs only in lightweight

sheeting profiles subjected to diaphragm action.

Figure 2-8: Modes of buckling of lipped channel in bending (Yu, 2001)

2.3.2.1 Local Buckling and Post-Buckling Strength of Thin Plate Elements

CFS sections have low width to thickness ratio which leads to local buckling when

subjected to compression, shear, bending, or bearing stress below yield stress. For the

CFS I-beam, the thin flange which is subjected to load is possible to buckle locally too.

Hence, a major design consideration for such elements is local buckling.

Although, occurring of local buckling for CFS does not mean that the loading

capacity has been reached when its buckling stress has already arrived, but in many

cases they still withstand additional load in excess of the load at local buckling. Hence,

it still has greater strength called post-buckling strength.

18

Local buckling is common in most CFS cross-sections, this guarantee superior

economy than a heavier section without local buckling (Yu and Schafer, 2003). (Dundu

and Kemp, 2005) Carried out a research and observed stress concentrations, shear lag

and bearing deformations caused by back-to-back channels with a bolted connection

made local buckling more critical. They recommended a factor of 0.8 to the yield

moment and the buckling moment of resistance to take care of stress concentrations,

shear lag and bearing deformations of back-to-back channels.

Chu el al., (2005) investigated about the buckling behavior of CFS channel section

beams when subjected to uniformly distributed load. Their study emphasized on local

and distortional buckling, sections subjected to pure compression or bending have the

only prevalent result. The CFS member was under the effect of uniformly distributed

transverse load, the outcome of their study showed that for local buckling; there is no

practical difference in critical loads between the two loading systems.

However, significant differences exist for distortional buckling. For a uniformly

distributed loading, the critical load is higher than that of pure bending. The difference

in the critical loads of both cases has been proved to decrease with the beam length for

most practical cases.

Through computational and experimental study by (Cheng and Benjamm, 2003),

the developed testing plan and details have been shown to adequately restrict

distortional buckling and provided a simple repeatable test that generates the local

buckling flexural capacity for C and Z sections.

However, the overall agreement is slightly skewed by a number of quite

conservative predictions for non-slender members that had observable inelastic reserve

capacity (Mutest /My > 1).

Through all the previous researches, the direct strength method had a main

advantage in which it can predict the ratio for both slender and non-slender specimens.

For direct strength method, its concept based on determination of all elastic instabilities

for the gross section (i.e., local, distortional, and global buckling) and the load or

moment that drives the cross-section to yield. The test results indicated that many

improvements in the elastic buckling and effective width calculation of C and Z cross-

sections are still available.

19

2.3.2.2 Lateral Buckling and Deflection of CFS Beams

Lateral buckling or lateral-torsional buckling, occurs when a beam which is

subjected to bending stress about its major axis acquires a tendency to displace

laterally or vertically, for Instance displace at right angle to the direction of

loading, and twist, if not properly braced. This behavior of an I-section beam is

shown in Figure 2.12. In addition with this, the deflection history due to lateral-

torsional buckling of the I-beam is shown in Figure 2.13. Based on the Figure, the

beam deflects in the y direction or displace vertically, at distance of (v) from its

original location before the lateral buckling occurred. This type of vertical

deflection is considered as in-plane bending. Later, whenever the buckling load

reached, the beam buckles laterally, at a distance of (u), and the section rotates

about the Centre of rotation CLB at a degree of rotation, (ø) (Stone and Laboube,

2005).

Furthermore, most of the CFS beams are restrained against lateral movement,

either by the remaining members joined to the beam or by bracing such as anti-

sag bars. Such restraints reduce the potentiality of lateral buckling, but do not

necessarily eliminate this problem (Rhodes, 1991).

In cases of members with continuous restraint the lateral torsional buckling

capacity reaches a minimum value over a finite length of beam, whereas in the

absence of restraint the buckling capacity decreases indefinitely with length. Most

of the design standards for CFS provide criteria for the design of CFS I beams

against their lateral buckling behavior.

20

Figure 2-9: Lateral buckling of an I-section beam (Rhodes, 1991)

Figure 2-10: Deflection history of I beam due to lateral buckling (Yu, 2001)

2.4 Shear Connectors

The mechanism of composite action between steel cross-section and concrete slab

depends on the shear flow, therefore the design and execution of shear connector

elements need to be carefully conducted.

Adhesion, friction, and bearing are some of the mechanisms that shear connectors

provide for stresses transmission (Viest et al, 1997). Various types of shear connectors

have been studied and introduced. In this study the steel CFS beam is connected to

Ferro-cement slab using bolts as a shear connector.

21

2.5 Review of Previous Investigations on Ferro-cement slab

(Shannag and Tareq) (2007) had studied the combined effect of reinforcing steel

meshes and discontinuous fibers as a single reinforcement in the thin mortar specimens

on the flexural behavior of Ferro-cement slabs. The researchers used 72 Ferro-cement

slabs with woven steel square wire mesh loaded with a point load in the center of the

slabs. Many parameters were studied in this research; mesh geometry, number of mesh

layers, using discontinuous glass and brass coated steel fiber. The results indicated that

as the wire mesh layers increased, the flexural strength of the Ferro-cement slabs

improved. While as the smallest spacing obtained in the wire mesh, the improved

flexural behavior obtained.in addition to, using fibers in the cement matrix improved

the flexural strength and energy absorption of Ferro-cement slabs.

(Al-Rifaie and Joma'ah) (2010) had studied the structure and the ultimate strength

of square Ferro-cement slabs of 50 x 50 cm in dimensions rested on I-beam cross-

section through attaching two Ferro-cement channel cross-sections back to back. The

flexural test carried out through subjecting the specimens to a point load. Four

specimens were tested; S1 and S2 were 2 cm thickness while S3 and S4 were 3 cm

thickness. For the reinforcement; S1 and S3 have two mesh layers while S2 and S4

have four mesh layers. The results indicated that all the slabs regardless the thickness or

the reinforcement was cracked in the middle. For S2, S3, and S1 the failure was through

the slabs, while for S4, the failure was through the beam at failure load 64 N.

(Wafa and Fukuzawa) (2010) investigated the characteristics features of thin

composite Ferro-cement elements using different reinforcement meshes in flexure. The

parameters observed in their study included: the consequence of different types of

reinforcement meshes (stainless steel meshes and E-fiberglass meshes); amount of

mesh layers and different mesh diameters with opening size and also different types of

mortar materials as matrix (cement grout mortar and polymer–cement grout mortar) on

the first crack load; bending stiffness; ultimate flexural load; load–deflection behavior;

crack characteristics; energy absorption capacity; and ductility index. The test results

elucidate that the utilization of stainless steel meshes as reinforcement system in the

Ferro-cement thin composite elements greatly influenced the improvement of bending

characteristics such as first crack load, bending stiffness, ultimate flexural load, energy

22

absorption to failure, and numerous fine and well-distributed cracks with a smaller

width than while utilizing fiberglass meshes.

(Ibrahim) (2011) had studied the punching capacity of Ferro-cement square slabs

supported on the four edges. The Ferro-cement slabs were provided with a 8 mm

diameter steel bar on the perimeter of the slab to support the spacing of the steel mesh.

The studied parameters in this research are wire mesh volume fraction, slab thickness,

and the patch load pattern. The results indicated that as the volume fraction increased,

the punching behavior of the Ferro-cement increased. In addition to, the ductility and

the stiffness of the tested slab had increased by increasing the loaded area sizes.

(Shri and Thenmozhi) (2012) had studied the ductility properties of hybrid fiber

reinforced rectangular Ferro-cement slabs with dimensions of 30 x 70 cm. the studied

parameters were; modulus of rupture and deflection at ultimate load, service load, crack

width, and moment curvature. The results indicated that as the slab thickness increased,

the ductility increased. In addition to, increasing the fiber content from 0% to 0.3% had

increased the load carrying capacity.

(Ramliand and Tabassi) (2012) investigated the mechanical performance of

polymer-modified Ferro-cement in different exposure conditions. In the study, they

assessed the load-deflection characteristics, first crack strength, crack width and crack

spacing of three commercial polymer-modified Ferro-cement; styrene-butadiene rubber

(SBR), poly-acrylic ester (PAE) and vinyl acetate-ethylene (VAE), and unmodified

Ferro-cement elements cured in air and saltwater exposure conditions. The outcome of

the tests showed that continuous saltwater exposure greatly influence the performance

of polymer modified Ferro-cement in flexure by displaying higher experimental values

of the first crack load and ultimate strength of all the specimens. Polymer modified

Ferro-cement also exhibited lower average crack width compared to the unmodified

Ferro-cement, irrespective of the exposure conditions.

(Randhir and Darshan) (2014) had studied the effect of inclusion of steel fibers

to the cement mortar of Ferro-cement slabs reinforced with different number of wire

mesh layers. Also, the researchers studied the impact of using different number of wire

mesh layers on the flexural behavior of Ferro-cement slabs. The results obtained

showed that increasing the number of wire mesh layers had increased the flexural

strength and reduced the deflection occurred. In addition to, using steel fibers had a

23

positive impact on the flexural strength of the Ferro-cement slab comparing to the one

without steel fibers.

(Alhajri and Tahrir) (2016) had studied the composite behavior of Ferro-cement

slabs supported over u-shaped cold formed steel sections. The composite action

between the steel u-shaped beam and the Ferro-cement slab was through bolts. The

results indicated that increasing both the cold formed steel section thickness and the

number of wire mesh layers had improved the flexural behavior of the studied structure.

2.6 Summary

From the previous studies it can be observed that the use of CFS, concrete and

Ferro-cement are reported on beams and slabs. It is also observed that Ferro-cement

causes less or no deterioration on the structural elements compared with the

conventional concrete. The Ferro-cement-concrete composites studied which are

reported proves improving the performance of the structural elements in terms of

flexural and impact strengths, ultimate capacity, reduced crack width, fire resistance,

insulation resistance, energy absorption, ductility, shear resistance, etc.

Also, the CFS is light weight steel section and high efficiency as flexure members.

However, Cold-Formed-Ferro-cement Composites has more tendency of improving the

overall performances that are required of the structural elements. Therefore, it is highly

recommended that investigations using CFS-Ferro-cement Composites is essential.

24

Chapter Three: Experimental Work

3.1 General Research Outline

The study investigates experimentally the structural behavior of cold formed-Ferro-

cement composite slabs. Experimental work involved on full-scale testing on the

proposed composite slab test specimens. Nine full-scale CFS-Ferro-cement composite

beam specimens were tested in this program.

Full scale tests representing the actual behavior of CFS Ferro-cement composite

slabs under flexural load were carried out. Two major parameters were studied the

thickness of Ferro-cement slab and the spacing between bolts (shear connector)

connecting the Ferro-cement slab with the CFS section to perform a composite slab.

3.2 Materials

3.2.1 Cement

Ordinary Portland Cement (OPC) of ‘Tourah’ brand was used during the study.

The (OPC) used complied with the Type I Portland Cement as in Egyptian Standard

2008/2253. Initial and final settings of cement are shown in table 3.1.

Type of

cement

Specific

gravity

Initial setting

time

Final setting

time

CEMI 42.5 R 3.15 60 min 5h

Table 3-1 Initial and final settings of cement

3.2.2 Fine aggregate

Sand passing through 4.75 mm sieve was used as fine aggregate in mortar for

Ferro-cement. Sieve analysis test results and gradation curve are shown in table 3.2 and

figure 3.1. Fineness modulus, moisture content and the percentage of clay and fine

materials are also shown in table 3.3.

25

Sieve

size

(mm)

Weight

Retained

(gm.)

Cumulative

Weight

Retained

(gm.)

Cumulative

Retained

(%)

Passing

(%)

4.75 17 17 1.8 98.2

2.36 29 46 4.7 95.3

1.18 109 155 15.7 84.3

0.6 389 544 54.9 45.1

0.3 332 876 88.4 11.6

0.15 101 977 98.5 1.5

pan 15 992 100 0

Table 3-2 Sieve analysis test results

Grading Type: Well Graded

Figure 3-1 Fine aggregate grading curve

Type of

aggregate

Fineness

modulus

specific

gravity

moisture

content

% of clay and

fine

Natural sand 2.63 2.67 0.60% 1.20%

Table 3-3 Fineness modulus, moisture content and % of clay and fine materials

0

10

20

30

40

50

60

70

80

90

100

0 1 2 3 4 5

Passing %

Seive Size (mm)

26

3.2.3 Water

The water cement (W/C) ratio is an essential factor to determine the concrete

strength. It should not contain any substance, which can be harmful to the process of

hydration of cement and durability of concrete. In general, water, which is acceptable

for drinking, is suitable for the concrete mixing. In this study tap water was used for the

manufacture of the concrete.

3.2.4 Wire Meshes

Expanded steel wire mesh (1.5mm diameter) locally available in the market, was

used as the reinforcement of slab. Figure 3.2 depicts the photographic view of wire

mesh used. The dimensions of wire mesh are 20mm x 20mm.

Figure 3-2 the photographic view of wire mesh

3.2.5 Mortar

Mortar mix was conducted by mixer (electrically operated). Cement and natural

sand were used in making the Ferro-cement concrete in the ratio of 1:2.25 with a

water/cement ratio of 0.4.

27

3.2.6 Cold formed steel section

The CFS sections used in this study are supplied by one of the steel manufacturers

in Egypt. Cold- formed lipped channel steel sections with depth of 140mm and

thickness of 1.5mm were used as shown in figure 3.3.

Figure 3-3 Cold- formed lipped channel steel sections

3.2.7 Shear connector

Self-drilling screws of 6 mm in diameter, 60 mm in length and steel grade 4.6 were

used.

3.2.8 Mortar Compressive Strength Test

Along with this study, mortar cubes of 70mm size were used to determine the

compressive strength of mortar. Three cubes were used to determine the mortar

compressive strength at 7 and 28 days. The compressive strength of mortar was

obtained using cube compression test.

28

The cube compressive strength testing set up is shown in Figure 3.4. The results of

the material test of mortar are given in Table 3.4. It was observed that the average

compressive strength after 7 days is 29.1 MPA, while the average compressive strength

after 28 days is 38.3 MPA.

Figure 3-4 the cube compressive strength testing set up.

29

7 DAYS 28 days

Test

Compressive

strength

(MPA)

Average

comp.

strength

(MPA)

Compressive

strength

(MPA)

Average

comp.

strength

(MPA)

1

33

31.4

35.3

36 16.7 36.5

29.8 36.1

2

23.3

26.5

38.6

36.3 26.9 33.9

26 17.6

3

29.2

28.6

34.3

33.5 29.5 31.8

27.1 32.7

4

25.7

28.5

36.7

38 31.2 42.4

20.2 34.7

5

24.7

29.5

36.8

39.2 14.3 39.6

34.5 41.3

6

22.2

27.4

44.1

41.9 25.4 39.6

34.7 41.9

Table 3-4 the results of the material test of mortar

3.3 Full-Scale Flexural Test

Full scale testing of continuously supported composite slab was set up in this

research. The purpose of full-scale tests was to evaluate and determine the flexural

strength and behavior of CFS-Ferro-cement assembled together as composite slab. The

specimens were tested by using simply supported beam specimens of 2100mm length

between supports with uniformly loading system as shown in figure 3.8.

Hence, the ultimate flexural capacity of the proposed composite was determined.

The experimental work focused on the ultimate strength of the CFS-Ferro-cement

composite slabs which was obtained from their load-deflection curve and will be

discussed later in Chapter 4.

30

3.4 Test Specimens and Arrangement

A total of nine composite slab specimens were tested for full-scale testing and

details description of each specimen are summarized in Table 3.5. Figure 3.5 shows

layout of CFS-Ferro-cement composite slab specimen where the actual length of the

beam was 2400mm.

However, an excess of 150mm at the each end of the beam to the support was

purposely done to ensure that the beam was simply support with an effective length of

2100mm between the supports. The test was set-up in such a way that the beams should

fail in flexural. Hydraulic jack with load cell having a capacity of 10 tons was used.

The width of Ferro- cement slab was 1200 mm with thickness (30-40) mm. A

lipped C Channel section was formed with top flange attached to the Ferro-cement slab.

Self-drilling bolts of 6 mm in diameter, 60 mm in length and steel grade 4.6 was used to

connect the CFS-Ferro-cement slab. Two different spacing between bolts were used

(450mm and 150mm). One layer of expanded steel wire mesh (2400mm x 1200mm)

was used with spacing (20mm x 20mm).

The casting of slabs for all composite slabs utilized the same batch of mortar. This

was to ensure that the mortar properties remained similar in all specimens. Figure 3.6

shows the formwork, casting work and the composite slab test specimen respectively.

The test specimens were supported with a pin at one end and a roller at the other end to

indicate that the test was a simple supported beam structure. Deflections at the bottom

flange of the steel section and at the bottom of slab were monitored at the center-points

using dial gauges.

Figure 3.7 shows dial gauges arrangement in the specimen. The strain gauges were

installed in the mid-span section of the bottom flanges of CFS beam to measure strains

in the CFS beam and to monitor yielding of the beam. The strains were measured using

linear strain gauges with the length of 100mm. The strain gauges were placed

longitudinally in the direction of the span so as to measure the longitudinal (flexural)

stresses. Figure 3.8 shows the setting up of the tests for all specimens.

31

Group

no. Slab

Slab

Thickness

Spacing between

bolts Type of CFS Ferro-cement slab

1

FC1

3 cm 450 mm Partially composite FC2

FC3

FC4 150 mm Fully composite

2

FC5

4 cm

450 mm Partially composite FC6

FC7

150 mm Fully composite FC8

FC9

Table 3-5 Details description of composite slabs specimens

a) Layout of CFS-Ferro-cement composite slab specimen for group 1 (All dimensions in m

32

b) Layout of CFS-Ferro-cement composite slab specimen for group 1 (All dimensions in m)

Figure 3-5 layout of CFS-Ferro-cement composite slab specimen

33

a) Formwork of full-scale Ferro-cement slab

b) Casting and finishing process

34

c) CFS composite Ferro-cement slab test specimen

Figure 3-6 Preparation of the composite Ferro-cement slab specimen

Figure 3-7 Dial gauges arrangement in the specimen

35

Figure 3-8 testing up of the tests for all specimens

3.5 Test Procedures

After the instrumentation system had been set-up, the specimen was loaded up to

15% of the predicted value. After reaching the 15% of predicted load capacity, the

specimen was unloaded back. This procedure was carried out so as to enable the

specimen to be in equilibrium state. An increment of about 2 KN was adopted so that a

uniform data and gradual failure of the specimen was monitored.

The specimen was loaded until large deflection of the middle beam can be

observed. At this point, the loading sequence was controlled by the increasing of

deflection as a small increment of load has resulted. This procedure was continued until

the specimen had reached its failure state. The composite system was supposed to fail

when there was a large reduction in the applied load or when a large deformation

occurred at the middle beam of the tested specimen.

36

An important precaution was to restrain the composite Ferro-cement slab specimen

laterally at both ends of the beam so as to prevent lateral buckling of the CFS section

during loading as shown in Figure 3.9.

Figure 3-9 Restrain the CFS sections at both ends to prevent lateral bucking

37

Chapter Four: Results and Discussion

4.1 Introduction

The results of the full-scale test specimens are illustrated and discussed in this

chapter. The relationship between the load and maximum deflection of the tested

specimens are plotted. Discussion includes flexural behavior and ultimate bending

capacities. Nine full-scale continuously supported CFS Ferro-cement composite slabs

with variable parameters were tested until failure under uniformly loading system. The

main variables considered in the study are the thickness of Ferro-cement and the

spacing between bolts. The test program was conducted in Structural Laboratory at the

Cairo University in Egypt.

4.2 CFS-Ferro-cement composite slab behavior

The purpose of the flexural test is to study the moment capacity, the mode of

failure, deflection behavior, and strain distribution along the section of the tested

specimens. The tests present the result of single C-channel specimens composite with

Ferro-cement slab as shown in figure 4.1. The details of the specimens are illustrated in

Chapter 3. The results are summarized in Table 4.1.

Figure 4-1 CFS Ferro-cement composite slab

38

Group

no.

Slab

no.

First

Crack

Load

(KN)

Ultimate

Load

(KN)

Maximum Deflection (mm)

Point 1 Point 2 Point 3 Point 4 Point 5

1

FCS1 27 53 14.8 14.1 14 20.3 14.2

FCS2 22 55 17.1 17.6 15.5 20.5 15.5

FCS3 20 45 17.6 17.9 18.3 23 18.7

FCS4 23 68 22 21.9 18.9 30 19.2

2

FCS5 22 48 18.8 18.4 17.1 20.3 17.1

FCS6 37 57 17.2 16.7 17.4 20.6 17.1

FCS7 35 64 20.9 21.1 18.2 28.7 17.8

FCS8 31 64 20.6 21.1 18.1 28.5 18.1

FCS9 38 70 22.5 22.2 22.1 32 22.4

Table 4-1 Experimental results of full scale composite slab testing

4.2.1 Group 1

The load (KN) versus mid-span deflection (mm) for Group 1 specimens is shown

in figure 4.2. In this case, failure was due to sudden torsional buckling of CFS lipped

channel. All specimens in this group exhibited a similar mode of failure, which started

by formation of transverse cracks in the Ferro-cement slab followed by a sudden

torsional buckling of steel beam at a region of maximum bending moment due to large

deflection of the beams. The failure mode occurred at the middle of the beam due to

large deflection at maximum bending moment and torsional buckling of steel beam as

shown in figure 4.3. The longitudinal cracks are located at the Centre and extended

along the length of the Ferro-cement slab as shown in figure 4.4.

39

4.2.1.1 Ferro-cement slab 1

Load-deflection curve at point 1 Load-deflection curve at point 2


0

10

20

30

40

50

60

0 10 200

10

20

30

40

50

60

0 10 20

0

10

20

30

40

50

60

0 10 20

0

10

20

30

40

50

60

0 20 40

40

Load-deflection curve at point 5

a) Load versus mid span deflection for FCS1



0

10

20

30

40

50

60

0 5 10 15

0

10

20

30

40

50

60

0 10 20

0

10

20

30

40

50

60

0 10 20

41



b) Load versus mid span deflection for FCS2

0

10

20

30

40

50

60

0 10 20

0

10

20

30

40

50

60

0 20 40

0

10

20

30

40

50

60

0 10 20

42




0

5

10

15

20

25

30

35

40

45

50

0 10 20

0

5

10

15

20

25

30

35

40

45

50

0 10 20

0

5

10

15

20

25

30

35

40

45

50

0 10 20

0

5

10

15

20

25

30

35

40

45

50

0 20 40

43


c) Load versus mid span deflection for FCS3



0

5

10

15

20

25

30

35

40

45

50

0 10 20

0

10

20

30

40

50

60

70

80

0 20 40

0

10

20

30

40

50

60

70

80

0 20 40

44



d) Load versus mid span deflection for FCS4

Figure 4-2 Load versus mid span deflection for Group 1 specimens

0

10

20

30

40

50

60

70

80

0 10 20

0

10

20

30

40

50

60

70

80

0 20 40

0

10

20

30

40

50

60

70

80

0 10 20

45

a) Large deflection at the middle of the beam

b) Large deflection at the middle of the beam

Figure 4-3 Large deflection at the middle of the beam

46

Figure 4-4 Transverse and longitudinal cracks

4.2.2 Group 2

The load (KN) versus mid-span deflection (mm) for Group 2 specimens is shown

in Fig 4.5. In this case, failure was due to sudden torsional buckling of CFS lipped

channel. All specimens in this group exhibited a similar mode of failure, which started

by formation of transverse cracks in the Ferro-cement slab followed by a sudden

torsional buckling of steel beam at a region of maximum bending moment due to large

deflection of the beams. The failure mode occurred at the middle of the beam due to

large deflection at maximum bending moment and torsional buckling of steel beam as

shown in figure 4.6. The longitudinal cracks are located at the Centre and extended

along the length of the Ferro-cement slab as shown in figure 4.7.

47




0

10

20

30

40

50

60

0 10 200

10

20

30

40

50

60

0 10 20

0

10

20

30

40

50

60

0 10 20

0

10

20

30

40

50

60

0 10 20 30

48


a) Load versus mid span deflection for FCS5



0

10

20

30

40

50

60

0 5 10 15 20

0

10

20

30

40

50

60

0 10 20

0

10

20

30

40

50

60

0 10 20

49



b) Load versus mid span deflection for FCS6

0

10

20

30

40

50

60

0 10 20

0

10

20

30

40

50

60

0 10 20 30

0

10

20

30

40

50

60

0 10 20

50




0

10

20

30

40

50

60

70

0 20 40

0

10

20

30

40

50

60

70

0 20 40

0

10

20

30

40

50

60

70

0 10 20

0

10

20

30

40

50

60

70

0 20 40

51


c) Load versus mid span deflection for FCS7



0

10

20

30

40

50

60

70

0 10 20

0

10

20

30

40

50

60

70

0 10 20 300

10

20

30

40

50

60

70

0 10 20 30

52



d) Load versus mid span deflection for FCS8

0

10

20

30

40

50

60

70

0 10 200

10

20

30

40

50

60

70

0 20 40

0

10

20

30

40

50

60

70

0 10 20

53




0

10

20

30

40

50

60

70

80

0 10 20 30

0

10

20

30

40

50

60

70

80

0 10 20 30

0

10

20

30

40

50

60

70

80

0 10 20 300

10

20

30

40

50

60

70

80

0 10 20 30 40

54


e) Load versus mid span deflection for FCS9

Figure 4-5 Load versus mid span deflection for Group 2 specimens

a) Large deflection at the middle of the beam

0

10

20

30

40

50

60

70

80

0 10 20 30

55

b) Large deflection at the middle of the beam

Figure 4-6 Large deflection at the middle of the beam

Figure 4-7 Transverse and longitudinal cracks

56

4.2.3 Strain analysis

Graphs of load (KN) against strain at critical cross-section of the composite slabs

for all CFS-Ferro-cement composite slab specimens are given in Figure 4.8. In this

analysis, a critical cross-section is defined as the cross-section that has the earliest

yielding of the CFS beam, as the yielding represents the attainment of the rectangular

stress block. In, all beams, the critical cross-section was found at mid-span of the

beams.

Based on the graphs of load against strain at the critical cross-section for all CFS

beams, it can be seen that the highest tensile strain was measured at the mid of the

lower flange of CFS sections. The yielding of the CFS was caused by average load as

shown in Table 4.1 that gave strain reading which was placed at the lower flange of

CFS. The values of strain at ultimate load are tabulated in Table 4.2.

Group

no. Slab no.

Ultimate strain at mid span of CFS sections (10^-6)

Point 3 Point 4 Point 5

1

FCS1 515 918 515

FCS2 805 1208 837

FCS3 773 1240 725

FCS4 1014 1530 998

2

FCS5 644 1127 644

FCS6 564 966 515

FCS7 821 1304 885

FCS8 644 1079 676

FCS9 950 1610 982

Table 4-2 the values of strain at ultimate load for all CFS sections

57


Load strain curve at point 3 Load strain curve at point 4

Load strain curve at point 5

a) Load versus mid span strain for FCS1

0

10

20

30

40

50

60

0 500 1000

Strain

0

10

20

30

40

50

60

0 500 1000

0

10

20

30

40

50

60

0 200 400 600

58




b) Load versus mid span strain for FCS2

0

10

20

30

40

50

60

0 500 1000

0

10

20

30

40

50

60

0 1000 2000

0

10

20

30

40

50

60

0 500 1000

59




c) Load versus mid span strain for FCS3

0

5

10

15

20

25

30

35

40

45

50

0 500 1000

0

5

10

15

20

25

30

35

40

45

50

0 1000 2000

0

5

10

15

20

25

30

35

40

45

50

0 500 1000

60




d) Load versus mid span strain for FCS4

0

10

20

30

40

50

60

70

80

0 1000 20000

10

20

30

40

50

60

70

80

0 1000 2000

0

10

20

30

40

50

60

70

80

0 1000 2000

61




e) Load versus mid span strain for FCS5

0

10

20

30

40

50

60

0 200 400 600 8000

10

20

30

40

50

60

0 500 1000 1500

0

10

20

30

40

50

60

0 200 400 600 800

62




f) Load versus mid span strain for FCS6

0

10

20

30

40

50

60

0 200 400 6000

10

20

30

40

50

60

0 500 1000 1500

0

10

20

30

40

50

60

0 200 400 600

63




g) Load versus mid span strain for FCS7

0

10

20

30

40

50

60

70

0 500 10000

10

20

30

40

50

60

70

0 500 1000 1500

0

10

20

30

40

50

60

70

0 500 1000

64




h) Load versus mid span strain for FCS8

0

10

20

30

40

50

60

70

0 500 10000

10

20

30

40

50

60

70

0 1000 2000

0

10

20

30

40

50

60

70

0 500 1000

65




i) Load versus mid span strain for FCS9

Figure 4-8 load against strain at critical cross-section of the composite slabs for all CFS-

Ferro-cement composite slab specimens

0

10

20

30

40

50

60

70

80

0 500 1000

0

10

20

30

40

50

60

70

80

0 500 1000 1500 2000

0

10

20

30

40

50

60

70

80

0 500 1000 1500

66

4.3 Parameters Studied

4.3.1 Effect of Increasing the Slab Thickness

The thickness of the Ferro-cement slab is one of the variable parameters considered

in this full scale experimental program. Figure 4.9 and Figure 4.10 shows the mid span

deflection curves for the Ferro-cement slab and CFS beams in partially composite CFS

Ferro-cement slabs. It is noted that increasing the Ferro-cement slab thickness has not

significantly increased the maximum mid span deflection values.

Figure 4.11 and figure 4.12 shows the mid span load-deflection curves for the

Ferro-cement slab and CFS beams in fully composite CFS Ferro-cement slabs. It is

noted that increasing the Ferro-cement slab thickness has not significantly increased the

maximum mid span deflection values.

Table 4.3 shows the mid span ultimate strain values for CFS beams in both cases

partially and fully composite CFS Ferro-cement slab. It is noted that as the Ferro-

cement slab thickness has increased, the mid span strain has decreased due to reduction

in tensile stresses at the bottom flange of CFS section.

Figure 4-9 mid span load-deflection curves of Ferro-cement slab for partially composite

specimens

0

10

20

30

40

50

60

0 5 10 15 20

FC5

FC6

FC1

FC2

FC3

67

a) mid span load-deflection curves of right edge CFS beam

b) mid span load-deflection curves of middle CFS beam

0

10

20

30

40

50

60

0 5 10 15 20

FC5

FC6

FC1

FC2

FC3

0

10

20

30

40

50

60

0 5 10 15 20 25

FC5

FC6

FC1

FC2

FC3

68

c) mid span load-deflection curves of left edge CFS beam

Figure 4-10 mid span load-deflection curves of CFS beams for partially composite

specimens

Figure 4-11 mid span load-deflection curves of Ferro-cement slab for fully composite

specimens

0

10

20

30

40

50

60

0 5 10 15 20

FC5

FC6

FC1

FC2

FC3

0

10

20

30

40

50

60

70

80

0 5 10 15 20 25

FC4

FC7

FC8

FC9

69

a) mid span load-deflection curves of right edge CFS beam

b) mid span load-deflection curves of middle CFS beam

0

10

20

30

40

50

60

70

80

0 5 10 15 20 25

FC4

FC7

FC8

FC9

0

10

20

30

40

50

60

70

80

0 5 10 15 20 25 30 35

FC4

FC7

FC8

FC9

70

c) mid span load-deflection curves of left edge CFS beam

Figure 4-12 mid span load-deflection curves of CFS beams for fully composite specimens

Є reduction

%

Ultimate Strain at right edge beam,

Є (10^-6)

Type of CFS Ferro-

cement slab

Group

no.

- 676 Partially composite 1

17% 579.5 Partially composite 2

- 998 Fully composite 1

20% 829 Fully composite 2

Є reduction

%

Ultimate Strain at middle beam, Є

(10^-6)

Type of CFS Ferro-

cement slab

Group

no.


3% 1046.5 Partially composite 2


5% 1457 Fully composite 2

Є reduction

%

Ultimate Strain at left edge beam, Є

(10^-6)

Type of CFS Ferro-

cement slab

Group

no.


10% 604 Partially composite 2


15% 885.5 Fully composite 2

Table 4-3 the mid span ultimate strain values for CFS beams

0

10

20

30

40

50

60

70

80

0 5 10 15 20 25

FC4

FC7

FC8

FC9

71

4.3.2 Effect of increasing the number of Bolts Connecting the Ferro-

cement slab with the CFS-Section

The number of bolts connecting the Ferro-cement slab with CFS section is one of

the variable parameters considered in this full scale experimental program. Table 4.4

indicates that using spacing between bolts (150 mm) has increased the capacity load of the

fully composite section by almost one third the capacity load of the partially composite

section. This is due to an increase in the number of bolts connecting Ferro-cement slab with

CFS section while the Ferro-cement section is the same area.

Table 4.5 shows the maximum mid span deflections for Ferro-cement slab and CFS

beams in both cases partially and fully composite CFS Ferro-cement slab. It is noted

that as the number of bolts has increased in CFS Ferro-cement slab, the mid span

deflection has also increased.

Table 4.6 shows the ultimate mid span strain values for CFS beams in both cases

partially and fully composite CFS Ferro-cement slab. It is noted that as the number of

bolts has increased in CFS Ferro-cement slab, the mid span strain has also increased.

Pu increment % Ultimate Load, Pu, KN Type of CFS Ferro-cement slab Group no.


36% 68 Fully composite



Table 4-4 the ultimate loads of tested specimens

72

δ increment % Maximum Deflection at right edge

beam, δ, mm

Type of CFS Ferro-

cement slab Group no.

- 16.45 Partially composite 1

17% 19.2 Fully composite


17.50% 20.1 Fully composite

δ increment % Maximum Deflection at middle beam,

δ, mm

Type of CFS Ferro-

cement slab

Group

no.


47.00% 30 Fully composite



δ increment % Maximum Deflection at left edge beam,

δ, mm

Type of CFS Ferro-

cement slab

Group

no.





δ increment % Maximum Deflection at Ferro-

cement slab, δ, mm

Type of CFS Ferro-

cement slab

Group

no.





Table 4-5 the mid span deflections for CFS beams and Ferro-cement slab

73

Є increment % Ultimate Strain at right edge beam,

Є (10^-6)

Type of CFS Ferro-

cement slab

Group

no.





Є increment %

Ultimate Strain at middle beam, Є

(10^-6)

Type of CFS Ferro-

cement slab

Group

no.





Є increment %

Ultimate Strain at left edge beam, Є

(10^-6)

Type of CFS Ferro-

cement slab

Group

no.





Table 4-6 the mid span strain values for CFS beams

74

Chapter Five: Conclusions and Recommendations

5.1 Strength and Stiffness of Composite Slabs

The results of experimental tests on nine full-scale composite slab

specimens were presented and discussed in Chapter 4. All full-scale specimens

were continuously supported slabs with an effective length of 2100 mm. CFS

lipped C-section and Profiled Ferro-cement slab of (30-40) mm thickness and

1200 mm effective width were incorporated. The main variables considered in

the study are the thickness of Ferro-cement slab and the number of bolts

connecting Ferro-cement slab with CFS section. Based on the test results and

observations, it was conducted to a meet the objectives of the thesis as listed in

Chapter 1 earlier. The following conclusions can be made:

1. The proposed Ferro-cement slabs with the proposed shear connector

provided sufficient restrain to the flange of CFS beam and eliminate its

local buckling problem.

2. For all specimens, Most of the cracks were first developed

longitudinally parallel to the beam due to shear flow between the Ferro-

cement and steel section. The cracks developed transversely at the

middle cross section of the span as large deformation of the specimens

occurred.

3. In all specimens, the mode of failure was due to a sudden

local/distortional buckling of CFS beam.

4. As the number of bolts connecting the CFS section with Ferro-cement

slab has increased, the mid span deflection for Ferro-cement slab and

CFS sections has also increased.

5. The effect of increasing the thickness of Ferro-cement slab has not

significantly increased the load capacity of the composite slab. However,

the increase in slab thickness has delayed the formation of cracks at an

early stage.

6. As the thickness of Ferro-cement slab has increased, the mid span strain

for CFS sections has decreased due to reduction in tensile stresses at the

bottom flange of CFS section.

75

7. As the number of bolts connecting the CFS section with Ferro-cement

slab has increased, the mid span strain for CFS sections has also

increased.

8. Using spacing between bolts (150 mm) has increased the capacity load of

the fully composite section by almost one third the capacity load of the

partially composite section.

5.2 Recommendations

This study has showed very promising results in terms of strength, stiffness and

structural behavior. Therefore, the following suggestions and recommendations for

future investigations and development are drawn:

1. This work investigated the effects of two variables on the composite action

between profiled Ferro-cement slab and steel beam. Therefore, other

parameters could be considered in future work. For example, different CFS

sections (different web depth and flange width), different grade and type of

mortar. In addition, the thickness of CFS section and the number of layers

of wire mesh in Ferro-cement slab can be investigated.

2. Other types of shear connector may be investigated.

3. A study is needed on the behavior of CFS-Ferro-cement composite beam-

column connections. For a continuous composite construction, it is very

important to develop an understanding at the beam-column connection.

76

References

ACI Committee 549R (1997). State-of-the-Art Report on Ferrocement, Manual of

Concrete Practice, ACI, Farmington Hills, Michigan ACI 549R-97.

Ahmed, S.F.U. and Nimityogsku,l P. (1998). Improvement of Punching Shear

Resistance in Ferrocement Slabs. Journal of Ferrocement, 28(4): 325-336.

Al-Kubaisy, M.A. and Nedwell, P.J. (1999). Behavior and Strength of Ferrocement

Rectangular Beams in Shear. Journal of Ferrocement. 29(1): 1-16.

Al-Noury, S.I and Haq S. (1988). Ferrocement in Axial Tension. Journal of

Ferrocement, 18(2): 111-137.

Al-Rifai, W.N. and Al-Shukur, A.H.K. (2001). Effects of Wetting and Drying

Cycles in Fresh Water on the Flexural Strength of Ferrocement. Journal of

Ferrocement. 31(2): 101-108.

Al-Rifaie, W.N. and Joma'ah, M.M. (2010). Structural Behaviour of Ferrocement

System. Diyala Journal of Engineering Sciences, first Engineering Scientific

Conference, College of Engineering-University of Diyala, pp. 237-248.

Al-Sulaimani, G.J and Basunbal, I.A. (1991). Behaviour of Ferrocement under

Direct Shear. Journal of Ferrocement, 21(2): 109-117.

Arif, M., Akhtar S., Masood, A., Basi, F. and Garg, M. (2001). Flexural Behaviour

of Fly Ash Mortar Ferrocement Panels for Low Cost Housing. Journal of Ferrocement,

31(2): 125-135.

Arif, M., Pamkaj and Kuasik, S.K. (1999). Mechanical Behavior of Ferrocement

Composites: An Experimental Investigation. Cement and Concrete Composites, 21(4):

301-312.

Bhatacharyya, P., Tan, K.H. and Mansur, M.A. (2003). Flexural Moment Capacity

of Ferrocement Hollow Sandwich Panel System. Journal of Ferrocement. 33(3): 183-

189.

Cheng, Y. and Benjamm, W.S.( 2003) “Local buckling test on cold-formed steel

beam,” Journal of Structural Engineering, vol. 129(12), pp. 1596–1606.

77

Chu, X.T., Ye, Z.M., Kettle, R. and Li, L.Y. (2005). Buckling behavior of cold-

formed channel sections under uniformly distributed loads. Thin-Walled Structures,

43(4): 531-542.

Deierlein, G.G. (1988). Design of Moment Connections for Composite Framed

Structures. Ph.D. Thesis, Phil M. Ferguson Structural Engineering Laboratory,

University of Texas at Austin, Austin, Texas.

Dundu, M. and Kemp, A.R. (2005). Strength requirements of single cold-formed

channels connected back-to-back. Journal of Constructional Steel Research, 62(3): 250-

261.

Fox, D. M., R. M. Schuster and M. Strickland. (2008)."Innovative Composite Cold

Formed Steel Floor System." Nineteenth International Specialty Conference on Cold-

Formed Steel Structures, St. Louis, MO.

Hancock, G.J. (2003). Cold-formed steel structures. Journal of Constructional Steel

Research.

Hancock, G.J., Murray, T.M. and Ellifritt, D.S. (2001). Cold-Formed Steel

structures to the AISI specification. USA: Marcel Dekker.

Hawalder, M.N.A, Mansur, M.A. and Rahman, M. (1990). Thermal Behaviour of

Ferrocement. Journal of Ferrocement, 20(3): 231-239.

Hossainan, M.Z. and Inoue (2000). A Comparison of the Mechanical Properties of

Ferrocement Elements under Compression for Square and Chicken Meshes. Journal of

Ferrocement. 30(4): 319-343.

Hsu, H.L. and Chi, P.S. (2003). Flexural performance of symmetrical cold-formed

thin walled members under monotonic and cyclic loading. Thin-walled structures,

41(1): 47-67.

Ibrahim, H.M. (2011). Experimental investigation of ultimate capacity of wired

mesh-reinforced cementitious slabs. Construction and Building Materials, 25(1): 251-

259.

Kandaswamy,S.and Ramachandraiah, A. (2002). Sound Transmission Performance

on Ferrocement Panels. Journal of Ferrocement, 32(1): 59-67.

78

Kumar, A. (2005). Ferrocement box sections-viable option for floors and roof of

multi-storey buildings. Asian Journal of Civil Engineering (Building and Housing),

6(6): 569–582.

Lakkavalli, B.S. and Liu, Y. (2006). Experimental study of composite cold-formed

steel C-section floor joists. Journal of Constructional Steel Research, 62(10): 995-1006.

Lawson, R.M., Popo-Ola, S.O. and Varley, D.N. (2001). Innovative development

of light steel composites in buildings. In: Eligehausen, R. (ed.) International

Symposium on Connections between Steel and Concrete. Stuttgart, Germany RILEM

Publications SARL.

Liborio,J.B.L. and Hanai, J.B. (1992). Ferro-ement Durability: Some

Recommendations for Design and Production, Journal of Ferrocement. 22(3): 265-271.

M.jamal Shannag and Tareq Bin Ziyyad (2007). Flexural response of ferrocement

with fibrous cementitious matrices. Consruction and Building Materials, 21(6): 1198-

1205.

Mansur, M.A. and Ong, K.G.C. (1987). Shear Strength of Ferrocement Beams.

ACI Structural Journal. 84(1): 10-17.

Mansur, M.A. and Paramasivam, P. (1986). Cracking Behaviour and Ultimate

Strength of Ferrocement in Flexure. Journal of Ferrocement, 16 (4): 405-415.

Mansur, M.A., Ahmed, I. and Paramasivam, P. (2001). Punching Shear Strength of

Simply Supported Ferrocement Slabs. ASCE Journal of Materials in Civil Engineering,

13(6): 418-426.

Mansur, M.A. and. Kiritharan, T. (2001). Shear Strength of Ferrocement Structural

Sections, Journal of Ferrocement, 31(3): 195-211.

Mansur, M.A., Paramasivam, P., Wee, T.H. and Lim, H.B. (1996). Durability of

Ferrocement-a Case Study. Journal of Ferrocement, 26(1): 11-19.

Methews, M.S., Sudhakumar, J. and Thomas, A.V. (1992). Behaviour of

Ferrocement Roofing Panels under Periodic Heat Flow Conditions. Journal of

Ferrocement. 22(2): 125-133.

79

Montesinos, G.P. and Naaman, A.E. (2004). Parametric Evaluation of the Bending

Response of Ferrocement and Hybrid Composites with FRP Reinforcements. Journal of

Ferrocement. 34(2): 341-352.

Naaman, A.E. (2000). Ferrocement and Laminated Cementitious Composites. Ann

Arbor, Michigan, USA: Techno Press.

Onet, T., Magureanu, C. and Vescan, V. (1992). Aspects Concerning the Behavior

of Ferrocement in Flexure, Journal of Ferrocement, 22 (1): 1-9.

Parmasivam, P. and Tan, K.H. (1993). Punching Shear Strength of Ferrocement

Slabs. ACI Structural Journal, 90(3): 294-301.

Randhir J. Phalke and Darshan G. Gaidhankar (2014). Flexural behavior of

ferrocement slab panels using welded square mesh by incorporating steel fibers.

International Journal of Emerging Trends in Engineering and Development, 3(5): 756-

763.

Rao, P.K. (1992). Stress-Strain Behavior of Ferrocement Elements under

Compression. Journal of Ferrocement, 22(4): 343-352.

Rhodes, J. (1991). Design of CFS members. Elsevier Applied Science Publisher.

S. Deepa Shri and R. Thenmozhi (2012). Flexural behavior of hybrid ferrocement

slabs with micro-concrete and fibers. International Journal of Emerging Trends in

Engineering and Development, 4(2): 165-177.

Sabnis, G.M. (1979). Handbook of Composite Construction Engineering. Van

Nostrand Reinhold Company, New York.

Salimullah, M. (1994). Ferrocement Roofing Elements: The Solution of the Middle

and Low Income Housing-The Bangladesh Experience. Journal of Ferrocement. 24(1):

51-56.

Shaari, S.N. and Ismail E. (2003). Promoting the use of industrialised building

systems and modular coordination in the Malaysia construction industry. Board of

Engineer Malaysia. Bulletin ingénieur.

Somayaji, S. and Naaman, A.E. (1981). Stress-Strain Response and Cracking of

Ferrocement in Tension. Journal of Ferrocement, 11(2): 127-142.

80

Stone, T.A. and LaBoube, R.A. (2005) “Behavior of CFS built-up I-sections,”

Thin-Walled Structures, vol. 43, pp. 1805 – 1817.

Suksawang, N., Nassif, H.H. and Sanders, M. (2006). Analysis of Ferrocement-

Laminated Concrete Beams. Proceedings of Eight International Symposium and

Workshop on Ferrocement and Thin Reinforced cement Composites. 06 08 February,

Bangkok Thailand, IFS, 141-150.

Swamy, R.N. and Shaheen, Y.B.I. (1990). Tensile Behaviour of Thin Ferrocement

Plates. Proceedings of Thin-Section Fiber Reinforced Concrete and Ferrocement, USA.

American Concrete Institute, Detroit, MI.

M. Alhajri, M. M Tahrir, M. Azimi and J. Mirza (2016). Behavior of pre-cast u-

shaped composite beam integrating cold-formed steel with ferrocement slab. Thin

Walled Structures, 102: 18-29.

Viest, I.M., Colaco, J.P., Furlong, R.W., Griffis, L.G., Leon, R.T. and Wyllie, L.A.

Jr. (1997). Composite Construction: Design for Buildings. McGraw-Hill,

NewYork. W.W. Yu, CFS Design. 3rd Edition. USA: John Wiley & Sons, 2001

Wafa, M.A. and Fukuzawa, K. (2010). Characteristics of ferrocement thin

composite elements using various reinforcement meshes in flexure. Journal of

Reinforced Plastics and Composites.

Wang, S., Naaman, A.E. and Li, V.C. (2004). Bending response of hybrid

ferrocement plates with meshes and fibers. Journal of Ferrocement: Vol, 34 (1).

Xiong, J.G. and Singh, G. (1997). Review of the fatigue Behaviour of Ferrocement

in a Corrosive Environment, Journal of Ferrocement. 27(1): 7-18.

Yu, C. and Schafer, B.W. (2003). Local buckling tests on cold-formed steel beams.

Journal of structural engineering, 129(12): 1596-1606.

Yu, W.K., Chung, K.F. and Wong, M.F. (2005). Analysis of bolted moment

connections in cold-formed steel beam–column sub-frames. Journal of Constructional

Steel Research, 61(9): 1332-1352.

الملخص

ستقصاء السلوك الانشائى للبلاطات المستمرة المركبة من الفيروسيمنت حيث ان إيهدف البحث الى

ربطة قص. وقد أالبلاطات ترتكز على كمرات من الحديد المشكل على البارد متصله فيما بينها ب

ستغلال التاثيرالمركب بين القطاعات المشكله على البارد وبلاطات صمم هذا النظام لإ

ربطة القص. تعتبر القطاعات المشكلة أالفيروسيمنت كى تنتقل قوة القص فيما بينهم عن طريق

ستدامه عند نشائى هام فى الدول الناميه ومن مواد التشييد التى تتسم بالإإعلى البارد عنصر

على الرغم من المميزات السالف نيه والتجاريه منخفضة الارتفاع.ستخدامها فى المبانى السكإ

ذكرها إلا انه لا يوجد بيانات كافيه عن الأداء والسلوك الخاص بالقطاعات المشكله على البارد عند

إستخدامها فى الإنشاءات المركبه. بالإضافة الى ما سبق تعتبر بلاطات الفيروسيمنت منخفضة

وبناءً على ما سبق تم إستحداث .ن سريعة التشرخ نظراً لسماكتها الصغيرهالجساءة وبالتالى تكو

concrete deckنظام بلاطات من قطاعات من الحديد المشكل على البارد ليكون بديلاً عن "

systemويقوم هذا ." عند تنفيذه فى اسقف واسطح المبانى السكنيه والتجاريه منخفضة الارتفاع

ستخدام خلطه اسمنتيه مكونة من رمل واسمنت ومسلحه بشبكة معدنية النظام المستحدث على إ

ويعتمد هذا البحث على التجارب العمليه لعدد تسع نماذج بالأبعاد الحقيقيه لإختبار .خفيفة الوزن

النظام السابق من حيث سمك البلاطه الامثل والمسافات بين المسامير مع استخدام نوع موحد من

أربطة القص وشبكة معدنية واحدة لتسليح البلاطه.

زكريا تونسىادهم السيد 20/7/1991

مصري1/3/0142 / /8201

ماجستير العلوم هندسة إنشائية

أ.د. متولى ابو حمد

أ.د. سامح يوسف محفوظ

:مهندس تاريخ الميلاد:

الجنسية: تاريخ التسجيل:

تاريخ المنح: الدرجة: القسم:

المشرفون:

:الممتحنون

:الرسالة عنواند الحدي ات منلبلاطات الادوار المركبة من الفيروسيمنت مع كمرالسلوك الانحنائى المشكل على البارد

ة:الدال الكلمات شبك سلك بلاطات فيروسيمنت, رباط قص, قطاع من الحديد المشكل على البارد و

ت المركبة من الفيروسيمنت مع كمرا لبلاطاتلالانحنائى السلوك

من الحديد المشكل على البارد

إعداد ادهم السيد زكريا تونسى

جامعة القاهرة -الهندسة كلية إلى مقدمة رسالة

ماجستير العلوم كجزء من متطلبات الحصول علي درجة

في

الهندسة الإنشائية

يعتمد من لجنة الممتحنين:

أ.د.

أ.د.

أ.د.

ت المركبة من الفيروسيمنت مع كمرا لبلاطاتلالانحنائى السلوك





في


تحت إشراف

سامح يوسف محفوظ /الدكتور الأستاذأستاذ مساعد فى المنشات المعدنية

رئيس قسم هندسة التشييد والبناءالاكاديمية العربية للعلوم والتكنولوجيا والنقل

البحرى

متولى ابو حمد /الدكتور الأستاذ أستاذ فى المنشات المعدنية والكبارى

الهندسة الإنشائيةقسم جامعة القاهرة

جامعة القاهرة –كلية الهندسة

جمهورية مصر العربية –الجيزة 2018

ت المركبة من الفيروسيمنت مع كمرا بلاطاتلالانحنائى ل السلوك





في


جامعة القاهرة –كلية الهندسة

جمهورية مصر العربية –الجيزة

2018

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