Embed Size (px)
Citation preview
INDIAN INSTITUTE OF TECHNOLOGY ROORKEE
STRUCTURAL BEHAVIOUR OF CONCRETE BLOCK
PAVEMENT: A REVIEW
TRANSPORTATION INFRASTRUCTURE PROJECTS : CONCEPTION
TO EXECUTION (TIPCE) - 2019
A presentation
on
Sumit Nandi
Research Scholar
Civil Engineering Department (CED)
Indian Institute of Technology Roorkee
Dr. G. D. Ransinchung R. N.
Associate Professor
Civil Engineering Department (CED)
Indian Institute of Technology Roorkee
2
CONTENTST
IPC
E -
2019
❖ INTRODUCTION TO PAVER BLOCKS
❖ ADVANTAGES OF CONCRETE BLOCK PAVEMENT
❖ HISTORY OF PAVER BLOCKS
❖ USAGE STATISTICS
❖ APPLICATIONS OF PAVER BLOCKS
❖ FEATURES OF PAVER BLOCKS
❖ JOINTING AND BEDDING SAND
❖ EDGE RESTRAINT
❖ INTERLOCK MECHANISM
❖ LOAD DEFLECTION BEHAVIOR
❖ LOAD REPEATATION
❖ JOINT FILLING AND THICKNESS VARIATION
❖ CONCLUSIONS
❖ REFERENCES
3
PAVER BLOCKS: PART OF BLOCK PAVEMENTT
IPC
E -
2019
• Paver blocks form a part of the segmental
paving system.
• The individual paving units are bedded and
jointed in the sand rather than the age-old
system of continuous paving (Panda and Ghosh
2002 b).
• Substructure beneath the bedding sand is
similar to that of a conventional flexible
pavement.
• The major structural components of the
concrete block pavements are:
(1) Block Pavers
(2) Bedding and Jointing Sands
(3) Edge Restraints
(4) Base-course and Sub-base
(5) Sub-grade
Figure : Components of block pavement (Panda and
Ghosh 2002 a)
4
ADVANTAGES OF CONCRETE BLOCK PAVEMENTT
IPC
E -
2019
EASY MAINTENANCE AND
REPAIR
CONCRETE
BLOCK
PAVEMENT
(CBP)
ACCESS TO UTILITIES
LOWER MAINTENANCE
COSTS
AESTHETICALLY
PLEASING
FREEZE-THAW RESISTANCE
WITHSTANDING
DEICING SALTS
UNAFFECTED BY SPILLAGE
OF OILs
RESTRICT THE SPEED OF
VEHICLES
CRACKING
PHENOMENON FREE
5
PAVER BLOCKS: HISTORYT
IPC
E -
2019
4000 BC
• First record of stone paving in Assyria.
2000 BC
• Flagstones were being used to pave village streets. Road-making using brick common in Mesopotamia.
300 BC• Clay brick paving in use in India.
1950 AD
• Post World War II. Shortage of coal. Concrete pavers were first introduced in The Netherlands as an alternative to the kiln-fired brick paving units then in use.
• Spread quickly to Germany, Austria, Belgium, France, and England.
1970s AD
• Concrete pavers came to the United States.
6
PAVER BLOCKS: HISTORYT
IPC
E -
2019
BLOCK SHAPE EVOLUTION (IRC:SP:63 2004)
INITIAL COST AND SIZE SIMILAR TO PAVING BRICK
DENTATED TO PROVIDE KEY WITH ADJOINING UNITS,
RETAINING ESSENTIALLY BRICK DIMENSIONS
NEW SHAPE FOR BETTER PERFORMANCE UNDER TRAFFIC AND PERMITTING MECHANICAL LAYING OF
BLOCKS
'X' SHAPED BLOCK FOR BETTER INTERLOCK AND FASTER MECHANISED PAVING
7
PAVER BLOCKS: USAGE STATISTICST
IPC
E -
2019
Figure : Use of pavers worldwide in
millions of square metres per annum
(CMA 2009)
Figure : Growth in concrete block
paving in South Africa (CMA 2009)
8
PAVER BLOCKS: APPLICATIONST
IPC
E -
2019
Figure : Paver Blocks at Intersections Figure : Paver Blocks at Pedestrian Crossings
Figure : Paver Blocks at Sidewalks Figure : Paver Blocks at Toll Plazas
Figure : Paver Blocks at Main Roads Figure : Paver Blocks at Car Parks
9
PAVER BLOCKS: APPLICATIONST
IPC
E -
2019
Figure : Paver Blocks at Factories and Warehouses Figure : Paver Blocks at Container Depots
Figure : Paver Blocks at Embankments Figure : Paver Blocks in Stormwater channels
Figure : Paver Blocks at Roof Deck Figure : Paver Blocks used to create picture
10
PAVER BLOCKS: FEATURES (CATEGORIES)T
IPC
E -
2019
Three categories of paver shape have been recognized (Morrish 1980).
• Category A comprises dentate blocks which key into each other on all four faces.
• Category B comprises dentated blocks which key into one another on two faces only.
• Category C comprises non-dentated blocks which do not key together geometrically.
Figure : Different Categories of Blocks (IRC:SP:63 2004)
11
PAVER BLOCKS: FEATURES (TEST SETUP)T
IPC
E -
2019
Figure : Schematic Test-Setup for testing of Paver
Blocks (Panda and Ghosh 2002 a)
Figure : Highway accelerated loading instrument (Ling et
al. 2009)
12
PAVER BLOCKS: FEATURES (BLOCK SHAPES)T
IPC
E -
2019
• Higher vertical surface area
results in large load spreading
ability.
• Some early plate load studies
(Knapton 1976; Clark 1978)
contradicted this finding.
• Later accelerated trafficking
studies (Shackel 1980) and plate
load studies (Shackel et al. 1993)
established that shaped
(dentated) blocks exhibited
smaller deformation than
rectangular blocks of a similar
thickness installed in the same
laying pattern under the same
applied load.
Figure : Summary of paver block shapes available (CMA 2009)
13
PAVER BLOCKS: FEATURES (BLOCK SIZE)T
IPC
E -
2019
Figure : Effect of block sizes on behavior of block
pavement (Panda and Ghosh 2002 b)
• Smaller size blocks have more numbers of joint per
unit area than a larger block (Panda and Ghosh 2002 a).
• The tendency of rotation and translation of the
smaller block is higher than a larger block.
• This conclusion is inconsistent with earlier findings by
Shackel (1980).
14
PAVER BLOCKS: FEATURES (BLOCK THICKNESS)T
IPC
E -
2019
Figure : Rut depth as a function of block and base
thickness (Shackel 1980)
• As the block thickness increases the elastic
deformation of the pavement reduces.
• Knapton (1976) found pavement performance was
essentially independent of block thickness, whereas
Clark (1978) reported a small improvement in
pavement performance with an increase in block
thickness. Shackel (1980), Miura et al. (1984) and
Shackel et al. (1993) claimed that an increase in
block thickness reduced elastic deflection and the
stress transmitted to the subbase.
• Compounded effect of higher frictional resistance
and thrusting action between adjacent block at the
hinging point is more effective in case of thicker
blocks (Panda and Ghosh 2002 a).
15
PAVER BLOCKS: FEATURES (BLOCK STRENGTH)T
IPC
E -
2019
Figure : Effect of block strengths on the behavior of
block pavement (Panda and Ghosh 2002 b)
• The blocks of the in-service CBP undergo
compressive stresses due to traffic loading. The
bending stresses develop in blocks are negligible
because of block size and its aspect ratio.
• Concrete blocks behave as rigid bodies in CBP.
• Loads transfer to the adjacent blocks is by virtue of
its geometrical characteristics rather than the
strength of blocks.
• Shackel (1980), and Panda and Ghosh (2002 b)
concluded that the load associated performance of
block pavements was essentially independent of the
compressive strength of the blocks. The effect of
block strength on the load-deflection behaviour of
block pavement is shown in the adjacent figure.
16
PAVER BLOCKS: FEATURES (LAYING PATTERN)T
IPC
E -
2019
Figure : Three basic laying patterns for block
paving (CMA 2009)
Figure : Effect of laying pattern of blocks on behavior
of block pavement (Panda and Ghosh 2002 b)
• The most commonly used patterns are
herringbone, stretcher or running and basket-
weave or parquet bonds.
• Knapton (1976) found that laying pattern did not
significantly affect the static load-spreading
capacity of the pavement.
• Accelerated trafficking tests (Shackel 1980) have
been used to compare the performance of these
patterns. From plate load studies, Miura et al.
(1984) and Shackel et al. (1993) have reported that,
for a given shape and thickness, blocks laid in a
herringbone bond exhibited higher performance
than blocks laid in a stretcher bond.
• The Herringbone pattern can have three orientations
relative to the direction of traffic. It should be laid
at 45⁰ to the traffic to resist the traffic shear stresses.
17
PAVER BLOCKS: FEATURES (BEDDING SAND)T
IPC
E -
2019
Authors Specification (Thickness)
Eisenmann and Leykuf
(1988), Lilley and
Dowson (1988),
Hurmann (1997)
(European practice)
Compacted thickness of 50 mm
Rada et al. (1990)
(United States),
Shackel et al. (1993)
(Australia)
Compacted thicknesses of
20 - 30 mm
Simmons (1979) Compacted depth of 40 mm
minimum
Mavin (1980)
Compacted depth of 30 ± 10
mm, 10 mm tolerance to be kept
on the subbase
Authors Specification (Grading)
Lilley and Dowson
(1988)
5, 15 and 50 percent passing
(maximum) 75, 150, and 300
mm sieves respectively.
Sharp and Simmons
(1980)
Nominal size of 5 mm
(maximum), 10% or less
coarser than the 4.75 mm
sieve. Grains should not be
single sized and/or spherical
shaped. Less than 3%
clay/silt content.
Livneh et al. (1988)
Particle size of 9.52 mm
maximum. Not more than
10% should pass the 75
micron sieve.
Table : Thickness of Bedding Sand Table : Bedding Sand grading
18
PAVER BLOCKS: FEATURES (JOINTING SAND)T
IPC
E -
2019
Authors Specification (Joint Width)
Shackel et al. (1993),
Hurmann (1997)
2-4 mm uniform, narrow and
filled joints to be provided.
Knapton and
O’Grady (1983)
0.5-5 mm joints to be
provided for better pavement
performance
Lilley (1994)
Below 5 mm. Excess width
decreases the structural
capability of the wearing
course.
Authors Specification (Grading)
Lilley (1981), Hurman
(1997)
Similar to that of bedding
course.
Shackel (1980)
Particle size of 1.18 mm
maximum and less than 20%
finer than the 75 micron sieve.
It should be finer.
Knapton and O’Grady
(1983)
Finer than 2.36 mm sieve. As
per British Standards, Zone 2
sand found to be most effective.
Livneh et al. (1988)
Particle size of 1.2 mm
maximum and 10% finer than
75 micron.
Table : Joint width Table : Grading of Jointing Sand
19
PAVER BLOCKS: FEATURES (EDGE RESTRAINT)T
IPC
E -
2019
Figure : Edge Restraints (IRC:SP:63 2004)
Figure : Pavement deflections with and without edge
restraint (Panda and Ghosh 2002 b)
• Edge restraints are a key part of CBP.
• Edge restraints resist lateral movement, prevent
rotation of the pavers under load and restrict loss
of bedding sand material at the boundaries.
• Edge restraints are designed to remain stationary
while receiving impacts during installation, from
traffic loads and freeze-thaw cycles. Edge restraints
should be laid at all boundaries of the paved area or
between the joints of the edge restraints.
20
PAVER BLOCKS: FEATURES (INTERLOCK)T
IPC
E -
2019
Figure : Achievement of vertical interlock (Knapton and
Barber 1980 )
Figure : Achievement of rotational interlock (Knapton
and Barber 1980)
• Interlock has been defined as the inability of an
individual paver to move independently of its
neighbours.
• It has been categorized as having three components:
horizontal, rotational, and vertical.
• Interlock is of major importance for the prevention
of movement of pavers horizontally when trafficked
(Knapton and Barber 1979).
21
PAVER BLOCKS: FEATURES (INTERLOCK
MECHANISM)
TIP
CE
-2019
Figure : Effects of rotation on the wedging action of
pavers (Shackel and Lim 2003)
Figure : Effects of paver rotation on pavers laid in
herringbone bond (Shackel and Lim 2003)
22
CBP: LOAD DEFLECTION BEHAVIORT
IPC
E -
2019
• The load-deflection behavior is irrespective of block shape, size, strength, thickness, and laying pattern.
• It is seen that the pavement deflection increased in a nonlinear manner with increasing load. An
interesting observation is that the rate of deflection decreases with increasing load (Panda and Ghosh
2002 a).
• The results obtained are similar to that established in earlier plate load tests by Knapton (1976), Clark
(1978), and Miura et al. (1984).
Figure : Load spreading mechanism (Panda and Ghosh 2002 a)
23
CBP: LOAD REPEATATIONT
IPC
E -
2019
Figure : Effects of cycling 51 KN load on paver
blocks laid in a herringbone pattern (Panda and
Ghosh 2002 b)
Figure : Effects of load repetition
(Panda and Ghosh 2002 b)
• Panda and Ghosh (2002 b) reported that the load-
deflection response is nonlinear. Moreover, initially,
the repeated loading and unloading results into
deflection, which is not fully recovered.
• Permanent residual deformations develop due to load
repetition.
• Block pavements stiffen progressively with an
increase in the number of load repetitions
• During loading, additional compaction of sand under
blocks occurs, and some part of the energy is lost in
that way. As a result, the recovery is not full.
24
CBP: JOINT FILLING AND THICKNESS VARIATIONT
IPC
E -
2019
Figure : Need for complete filling of joints
(IRC:SP:63 2004)
Figure : Effect of thickness variations in paving
blocks (IRC:SP:63 2004)
25
CONCLUSIONST
IPC
E -
2019
➢ CBP is made up of a rigid material but the construction and behaviour have a resemblance to that of a
conventional asphalt pavement.
➢ Deflection of CBPs is influenced by the width of joint, jointing sand and bedding sand quality,
bedding sand thickness, block shape, block size, block thickness, and number of load repetitions.
➢ The vertical surface area of the block greatly affects the load transfer.
➢ Shaped blocks perform better compared to square or rectangular (undented) ones of similar thickness
laid in same laying pattern.
➢ Deflection of CBPs can be reduced by the use of larger blocks.
➢ The load associated performance of CBP is influenced by the pattern of laying with herringbone bond
giving the best performance. On the contrary, the block compressive strength does not have any effect
on the performance of the CBP.
➢ The joints between the paver blocks should be uniform, narrow and properly filled for optimum load
spreading by friction, and to reduce deflection an effective edge restraint should be provided.
➢ The jointing sand should contain lesser fines that is, particles passing 75-micron sieve for smaller joint
widths and the maximum size should be below the joint width provided.
26
CONCLUSIONST
IPC
E -
2019
➢ The bedding course acts as a cushion and should consist of course-grained sand providing a greater
resistance to shearing. A loose thickness of 50 mm can be provided.
➢ The response of CBP to load repetition is non-linear, so permanent residual deformations occur.
➢ With the number of load repetitions increased, there is a progressive stiffening of the block pavements.
So block pavements gradually attain its strength.
➢ The early deformation occurring in the very early life of the pavement and well before final lock-up can
be arrested by recompaction of the pavement prior to locking up (equilibrium).
➢ Functioning of CBPs largely depends on the unique interlocking mechanism of the paver blocks
involving the wedging action.
27
REFERENCEST
IPC
E -
2019
1. Clark, A.J., (1978). Block paving-research and development. Concrete, 12(7).
2. CMA (2009). Concrete Block Paving – Introduction. Concrete Manufacturers Association, Midrand, South
Africa.
3. Eisenmann, J. and Leykauf, G., (1988). Design of concrete block pavement in FRG. In Proc., 3rd Int. Conf.
on Concrete Block Paving, Pavitalia, Rome, pp.149–155.
4. Huurman, M., (1997). Permanent deformation in concrete block pavements. PhD thesis, Delft Univ. of
Technology, Delft, The Netherlands.
5. IS: 15658, (2006). Precast Concrete Blocks for Paving-Specifications. Indian Standards, New Delhi, India.
6. Knapton, J., (1976). The design of concrete block roads. Technical Rep. 42.515, Cement and Concrete
Association, Wexham Springs, U.K.
7. Knapton, J. and O’Grady, M., (1983). Structural behavior of concrete block paving. J. Concrete Soc., pp.17–
18.
8. Lilley, A., (1994). Size and block shape - Do they Matter. Concrete plant and production, 12, pp.123-123.
9. Lilley, A.A. and Dowson, A.J., (1988, May). Laying course sand for concrete block paving. In Proc., 3rd
Int. Conf. on Concrete Block Paving, Pavitalia, Rome, (pp. 457-462).
10. Livneh, M., Ishai, I. and Nesichi, S., (1988). Development of a pavement design methodology for concrete
block pavements in Israel. In Proc., 3rd Int. Conf. on Concrete Block Paving, Pavitalia, Rome, pp.94-101.
11. Mavin, K.C., (1980). Interlocking block paving in Australian residential streets. In Proc. of 1st International
Conf. on Concrete Block Paving.
12. Miura, Y., Takaura, M. and Tsuda, T., (1984). Structural design of concrete block pavements by CBR
method and its evaluation. In Proc., 2nd Int. Conf. on Concrete Block Paving (pp. 152-157). Delft, The
Netherlands: Delft Univ. of Technology.
13. Panda, B.C. and Ghosh, A.K., (2002). Structural behavior of concrete block paving. II: Concrete
blocks. Journal of transportation Engineering, 128(2), pp.130-135.
28
REFERENCEST
IPC
E -
2019
14. Panda, B.C. and Ghosh, A.K., (2002). Structural behavior of concrete block paving. I: sand in bed and
joints. Journal of Transportation Engineering, 128(2), pp.123-129.
15. Rada, G.R., Smith, D.R., Miller, J.S. and Witczak, M.W., (1990). Structural design of concrete block
pavements. Journal of transportation engineering, 116(5), pp.615-635.
16. Shackel, B., (1979). A Design Method for Interlocking Concrete Block Pavements. In Proceedings
Symposium on Precast Concrete Paving Block, Johannesburg, Concrete Society of Southern Africa.
17. Shackel, B., (1980). The performance of interlocking block pavements under accelerated trafficking.
In Proc., 1st Int. Conf. on Concrete Block Paving, Newcastle-upon-Tyne, U.K., (pp. 113-120).
18. Shackel, B., O'Keeffe, W. and O'Keeffe, L., (1993). Concrete block paving tested as articulated slabs.
In Fifth International Conference on Concrete Pavement Design and Rehabilitation Purdue University,
School of Civil Engineering; Federal Highway Administration; Portland Cement Association;
Transportation Research Board; Indiana Department of Transportation; Federal Aviation Administration;
and American Concrete Pavement Association. (Vol. 1).
19. Shackel, B., (2003). The challenges of concrete block paving as a mature technology. Pave Africa, pp.12-
15.
20. Sharp, K.G. and Simmons, M.J., (1980, August). Interlocking concrete blocks: state of the art review.
In Australian Road Research Board (ARRB) Conference, 10th, 1980, Sydney (Vol. 10, No. 2).
21. Simmons, M. J., (1979). Construction of interlocking concrete block pavements. Australian Road
Research Rep. ARR No. 90, pp.71–80.
29
QUESTIONST
IPC
E -
2019
30
TIP
CE
-2019
THANK YOU
