REVIEW NAUČNIH I STRUČNIH - Institut IMS rezultata 2015.pdfT 153 KERAMIČKI I PRAŠKASTI MATERIJALI..... 19 Rad u vrhunskom međunarodnom časopisu (M21)..... 20 Saopštenje sa međunarodnog

REVIEW

OF RESEARCH

AND BUSINESS RESULTS

OF THE IMS INSTITUTE

IN 2015

PREGLED

NAUČNIH I STRUČNIH

REZULTATA

INSTITUTA IMS

U 2015. GODINI

Institut za ispitivanje materijala a.d.

Beograd, decembar 2015.

PREGLED NAUČNIH I STRUČNIH REZULTATA

INSTITUTA IMS U 2015. GODINI

REVIEW OF RESEARCH AND BUSINESS RESULTS

OF THE IMS INSTITUTE IN 2015

Izdavač

Institut IMS a.d.

Beograd, Bulevar vojvode Mišića 43

[email protected]

www.institutims.rs

Za izdavača

Dr Vencislav Grabulov

Urednici

Dr Vencislav Grabulov

Dr Aleksandra Mitrović

Goran Petrović

Štampa

Razvojno-istraživački centar grafičkog inženjerstva

Tehnološko-metalurški fakultet, Beograd, Karnegijeva 4

Tiraž

250 primeraka

ISBN 978-86-82081-25-8

Karakteristika poslovanja Instituta za ispitivanje materijala za 2015. godinu je

povećan obim stručnih poslova koji je doveo do uvećanja prihoda. Pored

Centra za materijale i Sertifikacionog tela, koji svake godine beleže napredak,

poseban je rezultat je postigao Centar za puteve i geotehniku (sve celine) i deo

Centra za metale i energetiku. Odabrane stručne reference su, kao i svake

godine, impresivne. Uz sve probleme sa kojima je suočena domaća privreda, a

posebno građevinska industrija, Institut IMS je uspeo da obezbedi učešće u

najznačajnijim projektima u zemlji i regionu. U skladu sa višedecenijskom

tradicijom i ugledom, kao i širokim spektrom usluga koje pružamo, bili smo

angažovani na projektovanju, ispitivanjima i istraživanjima građevinskih

objekata, materijala i proizvoda, primeni tehnologija građenja i sistema

prednaprezanja.

Nabrojimo kao najznačajnije aktivnosti na koridorima X i XI i značajno učešće

u sanaciji brojnih klizišta. Posebno ističemo aktivnosti u realizaciji

makroprojekta brze pruge Beograd – Budimpešta. Nastavili smo rad na zaštiti

graditeljskog nasleđa, obnovi i izgradnji putnih objekata duž autoputeva i

magistralnih i regionalnih puteva u Srbiji, na revitalizaciji HE Đerdap 1 u

Kostolcu i na drugim hidro i termo-elektranama, povratili smo svoje mesto u

delu ispitivanja metalnih materijala razaranjem.

Što se naučno istraživačkog rada tiče, postignuti su rezultati na koje je Institut

IMS već navikao. Značajno je učešće naših saradnika ne realizaciji sedam

projekata tehnološkog razvoja, jedog projekta integralnih i interdisciplinarnih

istraživanja i četiri projekta iz programa osnovnih istraživanja.

Tokom 2015. godine, Naučno veće Instituta je usvojilo Program

naučnoistraživačkog rada i Program razvoja naučnoistraživačkog podmlatka za

period 2015-2019. godine. Osnova za donošenje ovih dokumenata je bilo

strateško opredeljenje rukovodstva Instituta ka daljem razvoju naučno-

istraživačke i inovacione delatnosti, kao i primeni rezultata istraživanja uz

poštovanje principa multidisciplinarnosti koja odlikuje Institut IMS, kao i

usmerena kadrovska politika. Ovu godinu posebno korakterišu napori

istraživača da se proširi međunarodna saradnja kroz učešće na projektima

Horizon 2020, COST i IPA. Naučni kadar je značajno poboljšan, pre svega

kroz opredeljenje mladih istraživača za dalje naučno usavršavanje koje se

reflektovalo na povećan broj istraživača sa istraživačkim zvanjima. Rezultati

istraživačkog rada su u skladu sa dosadašnjim trendom rasta broja publikacija

u međunarodnim časopisima i učešća istraživača na vodećim međunarodnim

skupovima.

Urednici

Pregled naučnih i stručnih rezultata u 2015. godini 1

SADRŽAJ

REZULTATI NAUČNO-ISTRAŽIVAČKOG RADA .................................. 5

T 150 TEHNOLOGIJA MATERIJALA ............................................................ 7

Saopštenje sa međunarodnog skupa štampano u celini (M33) ............................ 8

Saopštenje sa međunarodnog skupa štampano u izvodu (M34) ........................ 10

T 152 KOMPOZITNI MATERIJALI ............................................................. 11

Saopštenje sa međunarodnog skupa štampano u celini (M33) .......................... 12


Saopštenje sa skupa nacionalnog značaja štampano u celini (M63) ................. 17

Bitno poboljšan proizvod ili tehnologija (M84) ............................................... 18

T 153 KERAMIČKI I PRAŠKASTI MATERIJALI ...................................... 19

Rad u vrhunskom međunarodnom časopisu (M21) ........................................... 20




T 210 MAŠINSTVO, HIDRAULIKA, VAKUUMSKA TEHNOLOGIJA,

VIBRACIJE I AKUSTIČKI INŽENJERING .................................................. 33


2 Institut za ispitivanje materijala a.d. Beograd

T 220 GRAĐEVINARSTVO, HIDRAULIKA, PRIOBALNA

TEHNOLOGIJA, MEHANIKA TLA ............................................................... 39

Rad u tematskom zborniku vodećeg međunarodnog značaja (M13)................. 40

Rad u međunarodnom časopisu (M23).............................................................. 41


Rad u časopisu nacionalnog značaja (M52) ...................................................... 47


Bitno poboljšan proizvod ili tehnologija (M84) ............................................... 50

T 230 VISOKA GRADNJA ............................................................................. 51


T450 TEHNOLOGIJA METALA, METALURGIJA, PROIZVODI OD

METALA .......................................................................................................... 53

Rad u vrhunskom međunarodnom časopisu (M21) ........................................... 54

Rad u međunarodnom časopisu (M23).............................................................. 57

Predavanje po pozivu sa međunarodnog skupa štampano u celini (M31)......... 60


Rad u vodećem časopisu nacionalnog značaja (M51) ....................................... 68

B 003 EKOLOGIJA ......................................................................................... 71


T 150 PETROLOGIJA, MINERALOGIJA, GEOHEMIJA ........................... 73


Rad u vodećem časopisu nacionalnog značaja (M51) ....................................... 78



DOKTORSKE DISERTACIJE ......................................................................... 83

ORGANIZACIJA STRUČNIH SKUPOVA .................................................... 85

NAUČNI PROJEKTI FINANSIRANI OD STRANE MINISTARSTVA

PROSVETE, NAUKE I TEHNOLOŠKOG RAZVOJA .................................. 89

NAGRADE I PRIZNANJA .............................................................................. 93

ODABRANE STRUČNE REFERENCE ..................................................... 97

CENTAR ZA MATERIJALE .......................................................................... 99

CENTAR ZA METALE I ENERGETIKU ................................................... 109

CENTAR ZA PUTEVE I GEOTEHNIKU ................................................... 113

CENTAR ZA KONSTRUKCIJE I PREDNAPREZANJE ............................ 117

SERTIFIKACIONO TELO ............................................................................. 123

KONTROLNO TELO ..................................................................................... 125

PT PROVAJDER ............................................................................................ 127


RESULTS

OF SCIENTIFIC RESEARCH

WORK

REZULTATI

NAUČNO-ISTRAŽIVAČKOG

RADA


T 150

MATERIAL

TECHNOLOGY

T 150

TEHNOLOGIJA

MATERIJALA


SAOPŠTENJE SA MEĐUNARODNOG SKUPA

ŠTAMPANO U CELINI (M33)

K. Janković, D. Bojović, M. Stojanović, Lj. Lončar

THE USE OF MINE TAILINGS AS A PARTIAL AGGREGATE

REPLACEMENT IN SCC CONCRETE

International Conference Contemporary Achievement in Civil Engineering,

Subotica, 2015, 67-72.

In previous work, we found the tailings has no pozzolanic activity and that its

application in mortar and concrete can be made in the form of replacement of

participation in a certain percentage of aggregates. In this paper we discuss the

possibility of applying tailings in self-compacting concrete (SCC). Testing of

some properties of fresh and hardened SCC concrete in which 10 and 20%

fractions of 0/4 mm aggregate was replaced with tailings was performed. The test

results of compressive strength were compared with the standard.

Key words: talings, self-compacting concrete, aggregate.

K. Janković, D. Bojović, M. Stojanović, Lj. Lončar, L. Antić

THE INFLUENCE OF TAILINGS AS A PARTIAL SUBSTITUENTE IN

AGGREGATE WITH SUPLHATE-RESISTANT CEMENT TO SCC

CONCRETE DURABILITY

XVI International Symposium MASE, Ohrid, Macedonia, 2015, 319-324.

Tailings test results showed no pozzolanic activity and that its application in

concrete can be a partial replacement of aggregate. This paper presents the

possibility of using tailings in self-compacting concrete made with sulphate

resistant cement. Concrete specimens in which the aggregate fraction 0/4 mm was

replaced with 10 and 20% of tailings were examined. The resistance on freezing

and thawing with de-icing salts is used as an indicator of concrete durability.

Key words: talings, self-compacting concrete, aggregate.


K. Janković, M. Stojanović, D. Bojović, Lj. Lončar, L. Antić

THE POSSIBILITY OF THE USE OF CEM IV IN AGGRESSIVE

ENVIRONMENTS

XVI International Symposium MASE, Ohrid, Macedonia, 2015, 325-331.

Durability and exploitation life of a structure depends on the aggressiveness of

the environment in which it is located. The possibility of using CEM IV in

aggressive environments was investigated in this study. Two concrete mixtures

were made with pozzolanic cement with quantities of 310 and 360 kg/m3. The

results of testing the influence of aggressive solutions on concrete and its

freeze/thaw resistance were presented.

Key words: pozzolanic cement, chemical resistance, freeze/thaw resistance.



ŠTAMPANO U IZVODU (M34)

K. Janković, S. Stanković, D. Bojović, M. Stojanović, Lj. Miličić

THE INFLUENCE OF NANO-SILICA AND BARITE AGGREGATE ON

PROPERTIES OF ULTRA HIGH PERFORMANCE CONCRETE

Seventeenth Annual Conference YUCOMAT, Herceg Novi, Montenegro, 2015,

74.

Development of building materials with improving characteristics and its

application on increasing structure durability and sustainability is one of goals in

civil engineering. Application of nano-silica in concrete is one of the possibilities

to improve concrete properties. Concrete with nano-silica has denser and compact

microstructure. Nano-silica has higher pozzolanic reactivity than silica fume and

can reduce cement content in ultra high performance concrete (UHPC). Nano-

silica in cementitious materials influences on cement hydration and modify pore

structure. The main objective of this paper is to evaluate the influence of different

content of nano-silica and barite aggregate on properties of UHPC. Two types of

aggregate were used: quartz and barite. As a heavy-weight aggregate barite is

used to increase concrete density. By combining the properties of concrete with

nano-silica and concrete with heavy-weight aggregate, ultra high performance

concrete can be produced which have advantages of both types of concrete, i.e.

higher durability and radiation protection.

Key words: nano-silica, UHPC, barite, radiation protection.


T 152

COMPOSITE

MATERIALS

T 152

KOMPOZITNI

MATERIJALI




A.Mitrović, M. Zdujić

EVALUATION OF SELECTED SERBIAN KAOLIN CLAYS AS A RAW

MATERIAL FOR THE CEMENT AND CONCRETE INDYSTRY

XVI Balkan Mineral Processing Congress, Belgrade, 2015, Vol. I, 579-583.

This study presents the results related to the evaluation of selected kaolin clay

deposits in Serbia for production of metakaolin (MK). Three deposits, Vrbica and

Garaši from Aranđelovac basin, and Miličnica from Kolubara basin were

investigated, since it is well known that the development of pozzolanic properties

in calcined clays mainly depends on the nature and abundance of clay minerals

in the raw material. They were selected as they differ in kaolinite content,

presence of impurities, and crystallinity of the original kaolinite. Vrbica, high

quality kaolin clay, contains 80% of a medium ordered kaolinite and loss of

ignitation of 12.33%. Garaši and Miličnica, medium-quality kaolin clay, have

nearly the same mineralogical composition, 52–53% kaolinite and about 40%

quartz. The main difference between these clays is the degree of crystallinity.

Kaolinite of Garaši is a poorly ordered one, while kaolinite of Miličnica is a

medium ordered. Reactivity of the calcined clays also depends on the calcination

conditions and on the fineness of the final product.

The optimal calcination parameters, temperature and heating time are: 650 °C

and 90 min for Vrbica, 600 oC and 120 min for Garaši, and 650 oC and 120 min

for Miličnica, for which pozzolanic activities expressed in g Ca(OH)2/g MK are

0.65, 0.60, and 0.45, respectively.

According to pozzolanic activity, Vrbica and Garaši clays are valuable raw

material for obtaining pozzolanic additive in a form of metakaolin.

Keywords: kaolin clay, calcination, pozzolan.




A. Terzić, V. Mitić, Lj. Kocić

FRACTAL ANALYSIS OF HETEROGENEOUS CERAMIC

COMPOSITE MATERIALS

Materials Science & Technology 2015 (MS&T15), Columbus, OH, USA, 2015,

G-4.

Fractal dimensions theory employed in the surface topography analysis as a

means of explanation of composite materials mechanical and microstructural

characteristics has been studied. Fractal dimensions method is introduced by

employing a fractal concept of curvature radii of surfaces, depending on the

observation scale and horizontal lines intercepted by the investigated profile. The

structure of a ceramic composite material appears as a chaotically distributed

multiplicity of grains and pores. However, the recent investigations enabled

previewing structure of such materials via fractal dimension calculation in three

dimensions. The fractal dimension evaluated by grains’ profilographs obtained

by SEM micrographs are slightly above 1, which corresponds to the line

dimension. The fractal dimension of ceramic composite surface fragment

extracted from the SEM microphotograph is slightly higher than 2, while the

same photographs after the surface reconstruction procedure reveals surface

dimension that is typically between 2.5 and 2.8 which is pretty rough. Since

ceramic composite materials exhibit variety of mechanical and thermo-

mechanical properties like compressive and flexural strength, refractoriness,

refractoriness under load etc., it is important to investigate influence of fractal

structure on these properties. One of the main goals is to explore distribution of

micro-sized properties through a ceramic bulk. The new approach of 3D fractal

networks is applied and investigated on bauxite based refractory composite.

Keywords: ceramics, defects, roughness, inclusions, curvature radius, fractals.


A. Terzić, Z. Radojević, M.Arsenović, V. Mitić, S. Pašalić

APPLICATION OF THE FRACTAL METHOD IN THE CERAMIC

COMPOSITES SURFACE FLAWS CHARACTERIZATION

9th Int'l Conf & Expo on Advanced Ceramics & Composites (ICACC 2015),

Daytona, USA, 2015, 55.

Fractal dimensions theory employed in surface analysis as a means of structural

defects origin explanation was studied. This paper proposes new method of

roughness peaks curvature radii calculation and its application to glazed ceramic

composites surface tribological analysis. Fractal dimensions method is

introduced via asperity radius calculation by fractal concept of surfaces curvature

radii. Dependence of calculated radii on fractal dimension of studied curves was

established and notion of peak is mathematically formulated. The method

efficiency was tested by fractal curves simulations described by Brownian

motions. Microstructural investigations were conducted using SEM equipped

with EDS. Correlation between defects microstructure and ceramic composite

properties, based on fractal geometry and contact surface probability, has been

developed. Using fractals and grains contact surface statistics a reconstruction of

microstructure configurations has been successfully performed. Obtained results

indicated that fractal analysis and statistics model for contact surfaces of different

shapes were important for prognosis of ceramics properties and identifying

defects origin. The novel statistical approach to investigation of ceramic defects

was successfully conducted, as a result introducing fractal identification as means

of evaluating performance of ceramic composites.

Keywords: traditional ceramics, defects, roughness, inclusions, curvature radius,

fractals.

B. Ilić, A. Mitrović, M. Zdujić

THE EFFECT OF „AMORPHOUS KAOLIN“ ON PROPERTIES OF

CEMENT-BASED COMPOSITES

3rd Conference of The Serbian Society for Ceramic Materials, Belgrade, 2015,

118.

Although pozzolanic materials are used successfully in many countries,

nowadays the goal of many studies is to manufacture new pozzolans for making


high strength composites. In that sense, influence of different cement replacement

level with the amorphous kaolin, obtained by mechanochemical treatment, in the

cement-based composites was investigated. The cement-based composites, made

with amorphous kaolin and addition of hydrated lime, water glass, standardized

quartz sand and superplasticizer, were exposed to autoclaving curing. The

obtained result of the compressive strength 91.2MPa, in composite with cement

replacement level of 50% of amorphous kaolin, is slightly higher than those

obtained on control sample. It was concluded that amorphous kaolin can be

classified as advanced material, which use in cement-based composites have

numerous technical and ecological advantages.

Lj. Miličić, A. Terzić, Z. Radojević

THE INVESTIGATION OF HEAVY METALS LEACHING FROM

COAL ASH

Serbian Ceramic Society Conference Advanced Ceramic and Application IV –

New frontiers in multifunctional material science and processing, Belgrade,

2015, 76.

The production and the disposal of the coal ash that is generated and processed

in the power-plants represent a remarkable hazard in terms of the environmental

pollution. Both fly ash that is produced in electrostatic filters of the power plant

and the coal ash that is landfilled can be submitted to recycling and reusing

procedure in order to diminish the consequences which their disposal might have

on air, soil and underground water. The coal ash normally contains certain

quantity of heavy metals in the chemical composition. The heavy metals can be

regarded as toxic pollutants due to the high risk of their leaching when the ash is

in contact with water. Also, there is a certain risk of toxic elements leaching even

when coal ash is built-in the construction composites. However, the recycling and

reapplication of fly ash in building materials industry is only sustainable

economic solution for the ash disposal problem. Fly ash can be used as a

component in cement, mortar, concrete and bricks. Utilization potential of the fly

ash and landfilled ash, as the main residue from the lignite coal combustion in

Serbian power plants, was investigated in this study. Ash from filters from five

different power plants and four landfills were applied in several composite

samples (mortar, concrete and brick) without any physical or thermal pre-

treatment. The leachability of thepotentially toxic pollutants from the ash and ash


based products was investigated. The leaching behavior and potential

environmental impact of the following potentially hazardous elements was

tracked: Pb, Cd, Zn, Cu, Ni, Cr, Hg, As, Ba, Sb and Se. A detailed study of

physico-chemical characteristics of the ash, with accent on trace elements and the

chemical composition investigation is included. The results show that most of the

elements are more easily leachable from the ash in comparison with the ash based

composites. The leaching of investigated pollutants is within allowed range thus

investigated coal ashes can be reused in construction materials production.

Kywords: composite materials; fly ash; leaching; mechanical characteristics;

recycling.


SAOPŠTENJE SA SKUPA NACIONALNOG

ZNAČAJA ŠTAMPANO U CELINI (M63)

D. Jevtić, A. Mitrović, J. Markićević, A. Savić

SVOJSTVA CEMENTNIH MALTERA SA DODATKOM AMORFNOG

KAOLINA

International Conference Contemporary Achievements in Civil Engineering

2015, Subotica, 2015.

U radu su dati rezultati eksperimentalnih istraživanja fizičko-mehaničkih

svojstava maltera sa dodatkom amorfnog kaolina, koji je dobijen preradom

kaolinskih glina Aranđelovačkih basena. Posebna pažnja bila je posvećena

dominantnim mehaničkim parametrima maltera, čvrstoći pri pritisku, čvrstoći pri

savijanju i adheziji maltera za podlogu.

Ključne reči: amorfni kaolin, malter, kaolinska glina, fizičko-mehanička

svojstva.


BITNO POBOLJŠAN PROIZVOD

ILI TEHNOLOGIJA (M84)

A. Terzić, Z. Radojević, Lj. Miličić

PROIZVODNJA VATROSTALNOG TORKRET BETONA SA

DODATKOM LETEĆEG PEPELA KAO OTPADNOG MATERIJALA

ZA PRIMENU U INDUSTRIJSKIM TERMIČKIM AGREGATIMA

Tehničko rešenje je rezultat Projekta III 45008, Institut IMS a.d., Beograd;

Korisnik/naručilac: Fabrika „Šamot“ d.o.o., Aranđelovac; Godina izrade 2014,

godina prihvatanja TR od strane MNOTR 2015.


T 153

CERAMIC MATERIALS

AND POWDERS

T 153

KERAMIČKI

I PRAŠKASTI MATERIJALI


RAD U VRHUNSKOM MEĐUNARODNOM

ČASOPISU (M21)

A. Terzić, L. Pezo, Lj. Andrić, M. Arsenović

EFFECTS OF MECHANICAL ACTIVATION ON THE PARAMETERS

OF TALC QUALITY FOR CERAMICS PRODUCTION -

CHEMOMETRIC APPROACH

Composites: Part B: Engineering, 2015, Vol. 79, 660-666.

Talc is broadly used in the ceramic materials industry, either as a basic raw

material, or as filler, due to its chemical inertia, fragmentation proneness, thermal

stability, and refractoriness. The mechanical activation is frequently employed in

the direct enhancement of talc properties, and thereby in the design of talc based

composites with advanced performances. The differences in the set of the process

parameters measured before and after talc activation via ultra-centrifugal mill

Retsch ZM-1, and their influence on the grain-size distribution related

characteristics have been investigated. The mechanical treatments are

energetically unsustainable procedures, therefore the talc activation was

optimized on basis of assessment of the process variables (number of rotor

revolutions, current intensity, activation period, circumferential rotor speed and

mill capacity) effect on the final quality of product parameters (mesh sizes,

cumulative oversizes, average grain size, level of micronization kinetics, mesh

size appropriate to 95% micronized product cumulative undersize and specific

surface area). The activated product parameters in all experimental sequences

were obtained by the analytical procedure based on Rosin-Rammler-Sperling

equation. Response surface method, standard score analysis and principal

component analysis were used as a means of the optimization. Developed models

showed r2 values in the range of 0.714-0.908 and they were able to accurately

predict quality parameters in a wide range of process parameters. Standard score

analysis highlighted that the optimal sample was obtained using sieve mesh of

120 μm set of processing parameters (SS=1.0). Multiple comparison tests

revealed that the optimal variation in the processing parameters could reduce the

negative effect of talc samples inherent properties on the final score and improve

the activation procedure energetic and economic sustainability.


Keywords: fragmentation; analytical modeling; powder processing;

optimization; response surface analysis; principal component analysis.

M. Arsenović, L. Pezo, S. Stanković, Z. Radojević,

FACTOR SPACE DIFFERENTIATION OF BRICK CLAYS

ACCORDING TO MINERAL CONTENT: PREDICTION OF FINAL

BRICK PRODUCT QUALITY

Applied Clay Science, 2015, Vol. 115, 108-114.

Chemical composition and XRD qualitative analysis were used to calculate

mineral contents of 139 brick clay raw materials using LPNORM. The second

order polynomial models (SOP) for all the samples, which express the relation

between mineral contents and the characteristics of fired laboratory products, did

not fit to experimental data satisfactorily, due to low coefficients of determination

(r2). In order to improve the models, the samples are divided into four groups in

factor space (four quadrants), according to their mineral content similarity, using

principal component analysis (PCA). Predictive models of compressive strength

(CS), water absorption (WA), firing shrinkage (FS), weight loss during firing

(WLF) and volume mass of cubes (VMC) are obtained for each of the groups.

Second order polynomial (SOP) models are developed, and the influence of

certain minerals to brick clay bricks quality within the groups is discussed.

Developed models were able to predict the final quality of products in a wide

range of mineral content and temperature treatment data, showing coefficient of

determination (r2) in range between 0.704–0.995. In order to estimate the

adequacy of these models, the results were applied to the experimental data and

compared according to additional statistical tests, so the next values are

determined: coefficients of determination, reduced chi-square (χ2), mean bias

error (MBE), mean percent error (MPE) and root mean square error (RMSE).

Keywords: brick clay, minerals content, prediction of quality, Principal

Component Analyses, mathematical modeling.

http://www.kobson.nb.rs.proxy.kobson.nb.rs/nauka_u_srbiji.132.html?autor=Arsenovic%20Milica%20V


M. Arsenović, Z. Radojević, Ž. Jakšić, L. Pezo

MATHEMATICAL APPROACH TO APPLICATION OF INDUSTRIAL

WASTES IN CLAY BRICK PRODUCTION - PART I: TESTING AND

ANALYSIS

Ceramics International, 2015, Vol. 41, No. 3, 4890-4898.

The objective of this study was to investigate utilization potential of organic and

inorganic industrial wastes in clay bricks. Mineral composition of starting heavy

clay sample is tested using an X-ray diffractometer. Chemical content and loss

on ignition were determined in sludges, coal dust, fly and landfill ashes, soybean

crust, sawdust, sunflower hulls and their ash. Different ratios of wastes were

added to heavy clay, while the applied firing temperatures were in the range 850–

1000 °C. The laboratory samples (tiles, solid bricks and hollow blocks) were

tested by using the standard test methods. Changes in product׳s quality were

studied in terms of relative differences to ceramic-technological parameters

compared to samples without waste materials addition. It is noticed that all of the

additives increased weight loss, firing shrinkage and water absorption, while

decreasing compressive strength and volume mass. The greatest changes in

performances were observed with addition of organic materials, whereas, among

them, sunflower hulls initiated the lowest compressive strength. Inorganic

additives introduced fewer changes to fired products, while fly ash caused the

lowest decrease in compressive strength.

Response Surface Methodology (RSM) was applied and Second Order

Polynomial models (SOP) were used to show the effects of firing temperature,

waste materials addition and their quantity on characteristics of fired products.

High prediction accuracy was obtained, with coefficient of determination in the

range of 0.896–0.999. It was concluded that all of the analyzed materials can

generally be used in building bricks by taking advantage of low cost and

environmental protection, whereby thermal conductivity decreases.

Keywords: industrial wastes, heavy clay bricks, Response Surface Method,

Second Order Polynomial models.



M. Arsenović, Z. Radojević, Ž. Jakšić, L. Pezo

MATHEMATICAL APPROACH TO APPLICATION OF INDUSTRIAL

WASTES IN CLAY BRICK PRODUCTION-PART II: OPTIMIZATION

Ceramics International, 2015, Vol. 41, No. 3, 4899-4905.

The effects of organic and inorganic waste sludges, coal dust, fly and landfill

ashes, soybean crust, sawdust, sunflower flakes and their ash addition to

representative heavy clay were investigated. Changes introduced to shaping moist

(SM), shrinkage (ΔSk) and weight loss (ΔGk) in Bigot’s curve critical point, and

plasticity coefficient (PC) by Pfefferkorn were studied. The highest sensitivity to

drying showed samples with coal dust addition, while the greatest plasticity and

shaping moist was detected in samples with 50 wt% of fly and landfill ashes.

The influence of waste material used, its’ content and also firing temperature were

independent parameters that influenced compressive strength, water absorption,

firing shrinkage, weight loss during firing and volume mass as dependent

parameters. Second order polynomial mathematical models predicted fired

products characteristics, and were later used to determine the optimum conditions

by Response Surface Method (RSM), coupled with Fuzzy Synthetic Evaluation

algorithm (FSE), using trapezoidal function. The choice of the parameters

optimal interval that characterized fired products (water absorption, compressive

strength, weight loss during firing, firing shrinkage and volume mass), depended

on a final usage of the raw material in heavy clay brick industry. The optimization

results showed that sunflower hulls, wood sawdust, soybean husks and saturation

sludge are best to be used in solid bricks production. Coal dust, landfill ashes and

neutralization (inorganic) sludges are best to be used in hollow bricks production.

Sunflower hulls ash can be added in higher quantity to heavy clay to produce

blocks or in lower quantity in roof tiles. Fly ashes addition of 50 wt% allows roof

tiles production. The optimal temperature for solid bricks and hollow blocks

production is found to be 900–950 °C.

Keywords: industrial wastes, heavy clay industry, properties prediction, process

optimization.





A. Terzić, L. Pezo, Lj. Andrić, M. Trumić, G.Bogadanović

EFFECTS OF MECHANICAL ACTIVATION ON THE PARAMETERS

OF MICA QUALITY FOR APPLICATION IN INSULATION

MATERIALS - CHEMOMETRIC APPROACH

XVI Balkan Mineral Processing Congress, Belgrade, 2015, 1131-1137.

Mica is widely utilized in the production of insulation materials as filler due to

its chemical inertia, fragmentation proneness and dielectric properties.

Mechanical activation is frequently applied procedure for achieving direct

enhancement in a variety of mica properties and indirect improving of the mica

based composites characteristics. In this paper, the influence of the process

parameters on the grain-size distribution related characteristics of mica was

investigated for the mechanical activation performed using ultra-centrifugal mill

Retsch ZM-1. The initial and activated mica samples were thoroughly analyzed

and the activation induced changes in the properties were recorded. The

activation is energetically and economically unlikely sustainable procedure

therefore it is necessary that the process is optimized. Optimization of the mica

activation was based on the assessment of the effects of processing parameters

(number of rotor revolutions, current intensity, activation period, circumferential

rotor speed and mill capacity) on the product quality parameters (mesh sizes,

cumulative oversizes, average grain size, level of micronization kinetics, mesh

size appropriate to 95% micronized product cumulative undersize and specific

surface area). The activation product parameters in all experimental sequences

were obtained by analytical procedure based on Rosin-Rammler-Sperling

equation. Response surface method, Standard score analysis and Principal

component analysis were used for assessing the effect of process variables on the

final quality of product parameters. Developed models showed r2 values in the

range of 0.677-0.962 and they were able to accurately predict quality parameters

in a wide range of processing parameters. Standard score analysis highlighted that

the optimal sample was obtained using sieve mesh of 80μm set of processing

parameters (SS=0.81). Multiple comparison tests revealed that the optimal

variation in the processing parameters could reduce the negative effect of mica


samples inherent properties on the final score and improve activation procedure

energetic and economic sustainability.

Keywords: milling; grain size; optimization; response surface analysis; principal

component analysis.

A. Terzić, L. Pezo, Z. Radojević, Lj. Andrić

OPTIMIZATION OF AL2O3 SYNTHESIS PROCEDURE USED IN

PRODUCTION OF COMPOSITE CERAMIC MATERIALS

47th International October Conference on Mining and Metallurgy, Bor, 2015,

191-196.

Activation process variables influence on final quality of the product parameters

assessment was conveyed in order to optimize of Al2O3 thermo-mechanical

synthesis. Response surface method, Standard score analysis and Principal

component analysis were used for optimization. Established mathematical

models precisely predicted quality parameters in a broad range of processing

parameters. Standard Score Analysis showed that the optimal output was

obtained with sieve mesh of 120μm set of processing parameters. Diverse

comparison analyses disclosed that optimal set of activation process parameters

could reduce negative effect of γ-Al2O3 immanent properties on final score, and

enhance rate of γ to α transition which would improve energetic and economic

sustainability of activation applied in processing of alumina used in production

of high-temperature ceramics.

Keywords: Al2O3; milling; thermal applications; statistical analysis, analytical

modeling.

Lj. Andrić, A. Terzić, S. Pašalić, M. Petrov, D. Radulović

ACTIVATION OF PHOSPHATES FOR APPLICATION IN

COMPOSITE CERAMIC MATERIALS

47th International October Conference on Mining and Metallurgy, Bor, 2015, 77-

82.

The aim of the investigation was to increase the reactivity of the comminuted

phosphate ore for application in composite ceramic materials. The vibratory and


planetary mills were used as mechanical activators during experimental research.

The obtained results highlighted presence of both amorphous and crystallized

forms appearing in the observed phosphate ore mixture due to the specific genetic

conditions which rarely occur in deposits. The heterogenic composition of the ore

useful phosphoric part gave optimal results during the leaching test. For the first

time, the experiments of phosphate mechano-chemical activation from Lisina ore

deposit were performed in order to improve its reactivity.

Keywords: planetary mill, vibratory mill, reactivity, crystal structure, apatite.

M. Vasić, Z. Radojević

NON - ISOTHERMAL DRYING PROCESS OPTIMISATION - DRYING

OF CLAY TILES

IOP Conf. Series: Materials Science and Engineering 95, 2015, 12-25.

doi:10.1088/1757-897X/95/1/012025

In our previous studies we have developed a model for determination of the

variable effective diffusivity and identification of the exact transition points

between possible drying mechanisms. The next goal was to develop a drying

regime which could in advance characterize the real non isothermal process of

drying clay tiles. In order to do this four isothermal experiments were recorded.

Temperature and humidity were maintained at 350C / 75%; 450C / 70%; 450C /

60% and 500C / 60%; respectively in each experiment. All experimentally

collected data were analyzed and the exact transition points between possible

drying mechanisms were detected. Characteristic drying period (time) for each

isothermal drying mechanism was also detected. The real, non isothermal drying

process was approximated by 5 segments. In each of these segments

approximately isothermal drying condition were maintained. Temperature and

humidity of the drying air, in the first four segments, was maintained on the same

level as in recorded isothermal experiments while in the fifth segment, it were

maintained at 700C / 40%. The duration of the first four segments were calculated

from the diagrams Deff – t respectively for each experiment. The clay tile in

experiment five was dried without cracking using the proposed non isothermal

drying regime.




A. Terzić, L. Pezo, Lj. Andrić, Z. Radojević

OPTIMIZATION OF MECHANICAL ACTIVATION OF DIFFERENT

RAW MATERIALS USED IN PRODUCTION OF HIGH-

TEMPERATURE CERAMICS



2015, 69.

The assessment of the activation process variables influence on the final quality

of the product parameters was conveyed in order to optimize the mechanical

treatments of the different raw materials (mica, talc and alumina) used in the

production of high-temperature ceramics. The modification in the behavior of

activated samples has been correlated to the particle size distribution effect

produced by activation via an ultra-centrifugal mill. The differences in the set of

the process parameters determined before and after raw materials activation and

their influence on the grain-size distribution related characteristics have been

studied. The mechanical treatments are regarded as either energetically or

economically unsustainable procedures, therefore the activations were optimized

on basis of assessment of the process variables (number of rotor revolutions,

current intensity, activation period, circumferential rotor speed and mill capacity)

effect on the final quality of product parameters (mesh sizes of the sieves,

accumulated retained masses, average grain size, level of micronization kinetics,

mesh size appropriate to 95% of accumulated passing mass and specific surface

area). The activated product parameters in all experimental sequences were

obtained by the analytical procedure based on Rosin-Rammler-Sperling equation.

Response Surface Method, Standard Score Analysis and Principal Component

Analysis were used as means of the optimization. The established mathematical

models were able to precisely predict the quality parameters in a broad range of

processing parameters. Developed models showed r2 values in the range of 0.714-

0.988 for investigated raw materials. Standard Score Analysis highlighted that

the optimal sample was obtained using sieve mesh of 80μm set of processing

parameters (SS=0.81) for mica, sieve mesh of 120μm set of processing


parameters (SS=1.0) for talc, and sieve mesh of 120μm set of processing

parameters (SS=0.96) for alumina. Multiple comparison tests revealed that the

optimal variation in the processing parameters could reduce the negative effect

of raw materials inherent properties on the final score which would improve

energetic and economic sustainability of the activation applied for the processing

of raw materials utilized in production of high-temperature ceramics.

Keywords: mica; talc; alumina; ceramics; grain size; thermal applications;

analytical modeling.

A. Terzić, Lj. Andrić, Lj. Miličić, Z. Radojević

ENERGY TRANSFER AND CONVERSION RECORDED ON

MECHANICALLY ACTIVATED FLY ASH GRAINS

3rd International Conference Modern Technologies in Industrial Engineering –

Mod Tech 2015, Mamaia, Romania, 2015, 64.

The fly ash activation through mechanical milling is usually applied to improve

the ash properties in order to get composite materials with higher characteristics.

The activation technology based on mechanical energy action applied on treated

materials and is conducted by ultra-fine milling. In order to increase the reactivity

of lignite coal fly ash this paper focuses on optimization of mechanical activation

period. Also, the influence of the ash activation parameters on the grain-size

distribution related characteristics was studied during this research. The ash grain

inertia measurement through automatic grain counter (AGC) was performed. Due

this mechanically activated grains are the most convenient mineral form for

measurement of grain inertia since energy change that occurs in the mill material

system is recorded by them. The ash grains energy and properties could be

changed by mechanical forces. The ash was thoroughly analyzed, particularly in

its activated state, primarily by means of the X-ray diffraction method for a

reliable identification of the crystal phases and changes in the crystallinity,

followed by comparison of the SEM microphotographs of its initial and activated

state.

Keywords: milling; grain size; ceramic materials; mechanical activator;

recycling.


Z. Radojević, A. Terzić, M. Vasić, M. Arsenović

NON-TYPICAL DEFECTS ON SURFACES OF CERAMIC AND ROOF

TILES: NATURE AND THE CAUSES

3rd International Conference Modern Technologies in Industrial Engineering –

Mod Tech 2015, Mamaia, Romania, 2015, 255.

This research was conducted to identify the nature and the cause of non-typical

defects which appeared on the visible surfaces of ceramic and roof tiles.

Microstructural analysis was conducted via optical microscope and scanning

electron microscope coupled with energy dispersive spectrometer. Ceramic tiles

contained black spots and dark brown clusters with yellow halos. Black spots

originated from carbon contained in starting glaze raw materials. EDS analysis

of clusters of dark-brown color in the pores showed the presence of Fe, which is

found to affect the quality of the visible tile surface. Non-homogeneities on the

roof tiles surfaces appeared in the form of stains and manifested after immersions

in water or aspersing water on the tile surface. The cause of inhomogeneities was

a local phenomenon due to the porous structure of micro cracks caused by coarse

metallic grains that are imported with the raw materials.

Keywords: ceramic tiles; roof tiles; surface defects; impurities; microstructural

analysis.

A. Terzić, Lj.Kocić, V. Mitić, Z.Radojević, Lj. Pavlović, V. Pavlović

THE APPLICATION OF FRACTAL ANALYSIS IN INVESTIGATION

OF SYNTHESIZED Α-ALUMINA MICROSTRUCTURE AND

PROPERTIES



2015, 70.

The structure and performances of high temperature ceramic materials based on

alumina is controlled by application of different technological methods for

induction of transition of Al2O3 from its gamma to alpha phase. The thermo-

mechanical synthesis is one of the most frequently applied methods in the

production of α-Al2O3. This procedure requires extensive mechanical milling of

the γ-Al2O3, which is combined with thermal treatment. In this paper, the


microstructure and grain-size related properties of alumina in a variety of its

transformations have been investigated. Also, the impact of the mechanical

processing parameters on the alumina grain-size distribution affiliated

characteristics and on the γ to α phase transformation rate were studied. The

moderation in the alumina samples behavior has been correlated to the

granulometric and mineralogical changes induced by activation via an ultra-

centrifugal mill. Microstructural investigations were carried out using scanning

electron microscope equipped with energy dispersive spectrometer. Grain size

distribution was determined via cyclo-sizer. The new correlation between

microstructure and obtained properties of activated alumina, based on fractal

geometry and contact surface probability, has been developed. Using the fractals

and statistics of the grains contact surface, a reconstruction of microstructure

configurations, as grains shapes or intergranular contacts, has been successfully

done. Obtained results indicated that fractal analysis and statistics model for

contact surfaces of different shapes were very important for the prognosis of α-

Al2O3 microstructure and properties. The morphology of alumina grains

highlighted the validity of developing new structure analytical methods, based on

different grains’ shape geometries. The grains contact model based on ellipsoidal

geometry was presented as new modeling tool for structure research of activated

alumina. The directions of possible material properties prognosis are determined

according to the correlations synthesis–structure–property. The statistical

approach to the investigation of activated Al2O3 grains will improve energetic

and economic sustainability of the activation applied in the processing of alumina

used in production of high-temperature ceramics.

Kywords: Al2O3; high-temperaturte ceramics; grain size; thermal applications;

microstructure; fractals; grain contact surface.




M. Arsenović, L. Pezo, S. Stanković, Z. Radojević

PREDVIĐANJE KVALITETA OPEKARSKIH PROIZVODA NA

OSNOVU HEMIJSKOG SASTAVA POLAZNE SIROVINE

Nacionalna konferencija sa međunarodnim učešćem Građevinski materijali u

savremenom graditeljstvu, DIMK, Beograd, 2015, 59-66.

Kvalitet opekarskih sirovina značajno varira u pogledu hemijskih, mineraloških,

granulometrijskih i keramičko-tehnoloških karakteristika. Da bi se utvrdile

matematičke zakonitosti, analizirano je 139 uzoraka opekarskih sirovina iz Srbije.

Utvrđeno je da je matematički model koji najbolje opisuje vezu između sadržaja

makro oksida u sirovinama i osobina pečenih proizvoda u obliku polinoma

drugog reda (r2 vrednosti između 0,926-0,967). Razvijeni modeli su u stanju da

predvide osobine pečenih opekarskih proizvoda u širokom spektru sadržaja

oksida i temperature pečenja. Pomoću analize varijanse dobijenih modela

utvrđeno je da su najvažniji parametri koji utiču na čvrstoću pri pritisku

temperatura pečenja (kvadratni članovi u modelu), kao i sadržaj CaO i SiO2. Na

upijanje vode se pokazalo da su najuticajniji sadržaji CaO i SiO2 (kvadratni

članovi).

Ključne reči: opekarske sirovine, gotovi proizvodi, predviđanje osobina.

M. Vasić, Z. Radojević

PROUČAVANJE UTICAJA REŽIMA SUŠENJA NA KVALITET

OPEKARSKIH PROIZVODA

Građevinski materijali u savremenom graditeljstvu, Beograd, 2015, 101-110.

Proces sušenja opekarskih proizvoda u komornim i tunelskim sušarama spada u

procese sa znatnim utroškom energije. Uvođenje novih termotehničkih

postrojenja visokih performansi zahteva definisanje režima sušenja u zavisnosti

od svojstava sirovine od koje je proizvod oblikovan. U radu su prikazani rezultati

istraživanja keramičko – tehnoloških svojstava jedne domaće opekarske sirovine

a zatim i rezultati proučavanja ponašanja pri sušenju oblikovanih uzoraka.


Eksperimentalna istraživanja su obuhvatila praćenje linearnog skupljanja,

kinetike sušenja oblikovanih pločica kao i određivanje fizičko – mehaničkih

karakteristika osušenih i naknadno pečenih pločica. Analiza dobijenih podataka

omogućila je definisanje predloga režima sušenja koji je usklađen sa prirodom i

karakteristikama ispitivane opekarske sirovine.

Ključne reči: sušenje, opekarski proizvodi, režim sušenja.


T 210

MECHANICAL

ENGINEERING,

HYDRAULICS,

VACUUM TECHNOLOGY,

VIBRATION AND ACOUSTIC

ENGINEERING

T 210

MAŠINSTVO,

HIDRAULIKA,

VAKUUMSKA

TEHNOLOGIJA,

VIBRACIJE

I AKUSTIČKI INŽENJERING




A. Milenković, D. Boljević

PRIKAZ SOFTVERA ZA STATISTIČKU ANALIZU REZULTATA

MONITORINGA BUKE U ŽIVOTNOJ SREDINI

59. konferencija ETRAN 2015. i 2. internacionalna konferencija IcETRAN 2015,

Srebrno jezero, 2015.

U ovom radu je prikazano softversko rešenje SAN−B ver. 2.1 (Statistička analiza

nivoa buke) koje omogućava obradu rezultata monitoringa buke u životnoj

sredini. Softver je napravljen u skladu sa standardima SRPS ISO 1996-1 i SRPS

ISO 1996-2 i njime se vrši obrada i analiza podataka kontinualnih merenja buke.

U radu su obrađeni tehnički detalji koji su u vezi sa samom problematikom obrade

podataka, a najveći deo pažnje je posvećen objašnjenju samog softvera. Grafički

korisnički interfejs (GUI) je urađen u programskom paketu Visual Basic 6.0.

Ključne reči: monitoring buke u životnoj sredini; softver.

Aleksandar Milenković, Danica Boljević, Damir Savković

KAMENA VUNA KAO IZOLACIONI MATERIJAL U

GRAĐEVINSKOJ AKUSTICI

Nacionalna konferencija sa međunarodnim učešćem Građevinski materijali u

savremenom graditeljstvu, Beograd, 2015.

U građevinskoj akustici, odnosno zvučnoj zaštiti objekata, koriste se raznorodni

materijali za izolaciju od zvuka, kako vazdušnog kroz zidove i tavanice tako i

zvuka udara kroz međuspratne konstrukcije, a sve u cilju poboljšanja uslova

prijatnijeg življenja i rada u zgradama. Postoji više mogućih načina poboljšanja

tih uslova i u ovom radu će akcenat biti stavljen na izbor ispune za zvučnu

izolaciju u zidovima i podovima. U radu će biti prikazani rezultati laboratorijskih

ispitivanja akustičkih parametara pregradnih zidova i plivajućih podova sa

kamenom vunom različitih zapreminskih gustina, debljina i koeficijenata zvučne

apsorpcije, a u cilju odabira optimalnog rešenja za zahtevani kriterijum zvučne

zaštite.


Ključne reči: zvučna izolacija, kamena vuna, koeficijent zvučne apsorpcije,

pregradni zid, plivajući pod.

D. Boljević, A. Milenković, D. Savković

UTICAJ MINERALNE VUNE NA POBOLJŠANJE ZVUČNE

IZOLACIONE MOĆI LAKIH MONTAŽNIH ZIDOVA

OD GIPS-KARTONSKIH PLOČA

59. konferencija ETRAN 2015. i 2. internacionalna konferencija IcETRAN 2015,

Srebrno jezero, 2015.

U poslovnim objektima laki montažni pregradni zidovi od gipskartonskih ploča

su uglavnom zamenili teške homogene zidove od opeke i bloka. U stambenim

objektima istina i dalje se kao pregradni koriste homogeni zidovi od cigle i bloka,

ali svakako pri adaptaciji stanova laki montažni zidovi su prvi izbor. Ono što

ovakve zidove izdvaja je njihova laka konstrukcija, iako se njihove akustičke

osobine mogu porediti sa „teškim“ zidovima. U zavisnosti od zahteva za vrstom

pregrade odnosno od položaja takvog zida u objektu izbor tipa montažnog zida

nije nimalo lak, s obzirom na to da njihove akustičke osobine zavise od vrste

gipskartonskih ploča, njihove debljine, broja, ali i izbora ispune od mineralne

vune kao izolacionog materijala. U radu su prikazani eksperimentalni rezultati

merenja izolacione moći zida koji pokazuju doprinos mineralne vune kao i uticaj

izbora vrste mineralne vune u zidu od gips-kartonskih ploča, na zvučnu izolaciju.

Ključne reči: zvučna izolacija, mineralna vuna, zvučna apsorpcija, laki montažni

pregradni zid.

D. Boljević, A. Milenković, D. Savković

PRIKAZ REZULTATA MEĐULABORATORIJSKOG POREĐENJA

NACIONALNIH AKREDITOVANIH LABORATORIJA IZ OBLASTI

MERENJA NIVOA BUKE NA OTVORENOM PROSTORU

23. telekomunikacioni forum TELFOR 2015, Beograd, 2015.

Međulaboratorijska poređenja iz oblasti merenja nivoa buke u životnoj sredini u

organizaciji Provajdera za ispitivanje osposobljenosti Instituta IMS u Beogradu

organizovana su u avgustu mesecu ove godine na otvorenom prostoru kao deo


standardnog monitoringa nivoa buke prema ažurnoj verziji metode date u

standardu (SRPS) ISO 1996-2 i za slučaj koji odgovara merenju nivoa buke u

slobodnom polju. U međulaboratorijskom poređenju učestvovalo je sedam

akreditovanih laboratorija, od kojih su četiri bile inostrane, a tri laboratorije iz

Srbije.

Ključne reči: međulaboratorijsko poređenje, monitoring buke, vrednovanje

performansi učesnika.

H. Kurtović, A. Milenković, D. Boljević

PROVERA MOGUĆNOSTI DA SE PRORAČUNOM ODREDI

LABORATORIJSKA VREDNOST IZOLACIONE MOĆI LAKE

DVOSTRUKE PREGRADE

Zbornik radova 59. konferencija ETRAN 2015. i 2. internacionalna konferencija

IcETRAN 2015, Srebrno jezero, 2015.

U proračunima zvučne izolacije između prostorija na osnovu normi EN12354

polazi se od izolacione moći pregrada izmerene u laboratoriji, pa bilo bi od velike

koristi da kao orijentacija može da posluži neki računski postupak koji bi se takve

vrednosti mogle dobiti. Pokazalo se da ni u novijoj ni u starijoj literaturi nema

obrazaca po kojima bi se, bar približno, proračunala laboratorijska izolaciona

moć dvostruke pregrade izložene difuznom zvučnom polju, što je osnovni

podatak potreban za proračun. Izuzetak od male koristi za praksu je slučaj

normalne incidencije. U ovom radu su prikazani rezultati merenja izolacione

moći raznih tipova lakih gipsanih pregrada. Na osnovu dobijenih rezultata

analiziran je jedna metod proračuna izolacione moći koji bi dao približno iste

rezultate. U radu je prikazano šta je sve potrebno poznavati i u čemu su poteškoće

da se ovaj cilj postigne.

Ključne reči: zvučna izolacija, pregrade između prostorija, merenja, proračun.


M. Mijić, A. Milenković, D. Boljević, Ž. Flajs, D. Šumarac

DINAMIČKA POBUDA ENTERIJERSKIH OBLOGA U

PROSTORIJAMA SA OZVUČENJEM U KOME SE KORISTE

SABVUFER ZVUČNICI

Zbornik radova 59. konferencija ETRAN 2015. i 2. internacionalna konferencija

IcETRAN 2015, Srebrno jezero, 2015.

Savremena tehnologija audio sistema ustanovila je kao standard upotrebu

sabvufera u sistemima za ozvučavanja koncertnih i pozorišnih sala. Vremenom

je to postalo sastavni deo estetike savremene muzike, pa su sabvuferi neizostavni

čak i u kafićima. U takvim prostorima je konstatovano da se pri uobičajenim

nivoima reprodukcije zvuka javljaju značajne vibracije enterijerskih obloga, pa

su registrovane pojave oštećenja staklenih svetiljki i sličnih detalja u enterijeru.

Zbog toga je organizovano merenje nivoa vibracija na enterijerskim oblogama u

prostorima u kojima se koriste sabvuferi. U radu su prikazani rezultati takvih

merenja. Zaključeno je da postoji potreba za definisanjem minimalnih

mehaničkih kriterijuma za realizaciju enterijera gipsanim oblogama kojim bise

sprečile negativne posledice nastale primenom sabvufera.

Ključne reči: dinamička pobuda, prostorije sa ozvučenjem, sabvufer zvučnici,

enterijerske obloge.


T 220

CIVIL ENGINEERING,

HYDRAULIC ENGINEERING,

OFFSHORE TECHNOLOGY,

SOIL MECHANICS

T 220

GRAĐEVINARSTVO,

HIDRAULIKA,

PRIOBALNA

TEHNOLOGIJA,

MEHANIKA TLA


RAD U TEMATSKOM ZBORNIKU VODEĆEG

MEĐUNARODNOG ZNAČAJA (M13)

D. Berisavljević, N. Šušić, D. Rakić

SDMT – A TOOL FOR IN SITU IDENTIFICATION OF COLLAPSIBLE

SOILS

Third international conference on the flat dilatometer, DMT’15, Rome, 2015,

457-463.

Loess is a wind blown sediment characterized by an open structure. When

moistured or excessively loaded loess structure may collapse causing major

problems for engineering structures. Identification of vertical and horizontal

distribution of collapse prone zones in this type of soil is a first task of

geotechnical investigations. The paper presents two possible ways of identifying

collapse prone zones based on SDMT results. Reliability of constrained modulus

determined from DMT is also addressed.

Keywords: dilatometer, loess, collapse, intermediate parameters, constrained

modulus.


RAD U MEĐUNARODNOM ČASOPISU (M23)

G. Hadži-Niković, K. Ðoković, S. Vujić.

EFFECT OF MATRIC SUCTION ON ACTIVE EARTH PRESSURE IN

SILTY SOIL

Journal of Mining Science, 2015, Vol. 2, No. 2, 66-75.

Retaining structures are often driven at shallow depth well above the ground

water table where the soil is in a state of unsaturated condition. Estimation of

active earth pressure, which is very important in design of these structures, is

based on extending Rankine theory of earth pressure with respect a functional

relationship between the active pressure for an unsaturated soil and matric

suction. For an unsaturated silty soil, well and long-term above the ground water

table, it was determined the angle b on the basis of soil water characteristic

curves SWCC. For different depth of retaining walls and various matric suction

values, which can be constant or linear decreasing with depth, active earth

pressure and critical height of vertical unsupported excavation were determined.

The results in this paper confirm that matric suction in terrain decreases the value

of active pressure force on the retaining wall and considerably increases the

critical height of vertical unsupported slope.

Keywords: unsaturated soil, matric suction, soil-water characteristic curve,

laboratory testing, active pressure, stability of vertical slope.

J. Ćirilović, G. Mladenović, C. Queroz

IMPLEMENTATION OF PREVENTIVE MAINTENANCE IN

NETWORK-LEVEL OPTIMIZATION, CASE STUDY OF THE

SERBIAN LOW-VOLUME ROAD NETWORK

Transport Research Record, Vol. 2, 49-55.

Application of appropriate preventive maintenance (PM) treatments, at the right

time, extends the service life of pavements, resulting also in various benefits: (i)

to road users in terms of increase of ride comfort and safety; and (ii) to road

agencies, in the reduction of future maintenance costs and improvement of the

network condition. While PM treatments have usually been applied on the highly


trafficked sections of the Serbian national road network, they have not been

applied on the low volume part of the network.

The objective of this paper is to identify appropriate PM treatments for low

volume roads (LVR), model them into pavement management system (PMS), and

assess the potential benefits of their application compared to the current practice,

using the Serbian LVR network as a case study.

The World Bank’s Road Network Evaluation Tools (RONET) model, designed

to assess the current characteristics of road networks and their future performance

depending on different levels of interventions (and budgets), was selected for this

study. The model was modified under the study to incorporate use of PM

treatments. Modifications included adjustment of the pavement deterioration

curves to incorporate slower deterioration rate due to the application of crack

sealing and pothole patching, as well as surface dressings or thin overlays while

the pavement is still in good condition.

The results indicate that the use of preventive maintenance treatment would

result in increased net benefits and substantial reduction in future road agency

costs compared to the maintenance scenario without preventive maintenance.

Keywords: preventive maintenance, road agency costs, RONET.

Z. Berisavljević, D. Berisavljević, V. Čebašek

SHEAR STRENGTH PROPERTIES OF DIMITROVGRAD FLYSCH,

SOUTHEASTERN SERBIA

Bull. eng. geol. environ., Springer, Vol. 74 (3), 2015, 759-773.

Flysch deposits are common in Serbia. Approximately 15 % of the 250 km of

highways currently under construction will be constructed in flysch. In the most

southern part of the E80 project, close to the border crossing with Bulgaria,

construction of 3-km long cuts, often over 30 m high, is foreseen by the design.

The geology of this part of Serbia is mainly characterized by flysch deposits

represented by a sequence of sandstone and siltstone, interchanging in different

proportions. After excavation of a majority of the cuts, several slopes suffered

from global and structural instabilities. This required re-design of one part of the

cuts. For this purpose, a geological strength index (GSI) was estimated and the

structural features of rock discontinuities were observed on the faces of the


surface excavations. This information and data obtained from laboratory testing

enabled the determination of five characteristic rock mass types. For every type,

shear strength properties were determined based on three criteria: the Hoek–

Brown failure criterion; the Mohr–Coulomb criterion; and an hyperbolic

nonlinear envelope. During the process of converting the Hoek–Brown

parameters to the parameters of hyperbolic envelope, the Levenberg–Marquardt

algorithm (LMA) was utilized to solve for the nonlinear regression problem.

Verification of the parameters was performed on several examples. The median

angle pressure increases exponentially with the GSI value and ranges between

the value characteristic for clays and well-graded gravel. The maximum angle

difference is obtained for a GSI value of 30. The average normal effective stress

acting on the failed slopes, expressed in the form of the stress level ratio (SLR),

is below 0.5. This indicates that the curved part of the shear strength envelope is

utilized during the shearing. As such, the linear segment overestimates the shear

strength.

Keywords: Road cut, GSI, Shear strength, Nonlinear envelope.




Hadži-Niković G ., Rakić D., Đoković K.

EFFECT OF CHANGES IN MATRIC SUCTION ON SLOPE

STABILITY IN NATURAL UNSATURATED SOIL

XVI Conf. ECSMGE – Geotechnical Engineering for Infrastructure and

Development, Edinburgh, 2015, 1561-1566.

Stability analyses were performed for a real engineering-geological cross-section

of unsaturated Quaternary silt sediments. Unsaturated shear strength is a function

of the two stress variables: net normal stress and matric suction. Constitutive

equations (unsaturated shear strength – matric suction) and (angle b – matric

suction) were defined for these silty soils. These equations were established on

the basis of primary constitutive relationships for unsaturated soils by soil-water

characteristic curves (effective degree of saturation – matric suction). Soil-water

characteristic curves were obtained from results of experimental tests on draining

saturated soil samples under different pressures, performed for the first time in

Serbia, in a 15 bar pressure plate extractor, according ASTM. Effective shear

strength parameters c’ and ’ were also experimentally obtained from direct shear

tests. Stability analyses were performed using the GLE method for different

climate conditions, before and after rainfall, i.e. for different values of matric

suction. Stability analyses were performed for the same groundwater level, too.

It was confirmed that rainfall decreases the angle b and stability of natural

unsaturated soil slopes. Decreasing the b angle of unsaturated soil, due to

rainfall, decreases the safety factor of the slope faster for coarse-grained soil than

for finegrained soil.

Keywords: unsaturated soil, matric suction, slope stability, natural unsaturated

soil.


K. Đoković, J. Ćirilović, N. Šušić, G. Hadži-Niković

CORRELATIONS DEPENDENCE OF INDEX PROPERTIES AND

COMPACTION PARAMETERS OF SOIL

9th International Conference: Assesment, maintance and rehabilitation of

structures and settlements, Zlatibor, Serbia, 2015, 99-106.

The paper presents an application of regression analysis for the estimation of the

compaction parameters: maximum dry density (MDD) and optimum moisture

content (OMC) from index properties of the soils: liquid limit (LL), plastic limit

(LP), plasticity index (PI), grain-size distribution and specific gravity (Gs). The

samples belong to various clay types, and were obtained from cores from four

earthfill dams: Rovni, Selova, Prvonek and Barje, and were control samples

during soil compaction. The developed models can be used to estimate the

compaction parameters: (i) in the preliminary stages of the project development,

and (ii) in the course of the preliminary assessment of the suitability of a material

from borrow pits for use in earthfill structures.

Keywords: clay, compaction, earthfill dams, regression analyses.

K. Đoković, L. Čaki, N. Šušić, G. Hadži-Niković

RESEARCH DISPERSIVE FINEGRAIN SOILS BY PINHOLE TEST

6th International Conference Geotechnics in Civil Engineering, Vršac, 2015, 169-

174.

Dispersive clays are unfavorable soils for the construction of earth structures,

especially the core of earth dams, river embankments and road embankments. In

the study of dispersive soils one of the main problems is the identification of this

soil. Namely, the dispersive soils can not be identified by the standard

identification-classification tests such as sieve analysis or tests of plasticity. The

paper presents the results of identification and classification dispersive fine grain

soil by pinhole test.

Keywords: dispersive clays, pinhole test.


N. Šušić, D. Berisavljević, M. Prica, K. Đoković

DLT-TEST: DETERMINING PILE BEARING CAPACITY USING A

DYNAMIC METHOD

Over the past several years, the use of DLT method for determining pile load-

bearing capacity has been intensified both globally and domestically, as an

alternative to static load tests. The main advantage of the DLT over static tests is

reflected in the fact that it saves both time and money. The paper presents

theoretical bases of the DLT method as well as the manner of its application in-

situ. In conclusion, the paper offers an analysis of results and a procedure for

determining bearing capacity of piles, using the DLT method.

Keywords: pile, bearing capacity, dynamic method, principles, stress waves,

weights, sensors.

R. Spielhofer, N. Vajdić, J. Ćirilović, G. Mladenović

CROSS-ASSET RISK ASSESSMENT (X-ARA)

IABSE Conference – Structural Engineering: Providing Solutions to Global

Challenges, 2015, Geneva, Switzerland, 977-985.

This paper presents an outline of the CEDR Transnational Road Research

Programme funded research project “X-ARA – cross asset risk assessment”.

Objective and scope of the project are described and the approach is outlined. The

main part of this paper presents the findings of a desk study, carried out during

the project, on literature related to risk assessment in asset management and the

current practice on risk assessment of several European road operators.

Keywords: Asset management, cross asset management, risk assessment, road

infrastructure.


RAD U ČASOPISU NACIONALNOG

ZNAČAJA (M52)

Z. Berisavljević, D. Berisavljević, V. Čebašek, D. Rakić

ANALIZE STABILNOSTI POKOSA METODAMA GRANIČNE

RAVNOTEŽE I SMANJENJA PARAMETARA ČVRSTOĆE TLA

Građevinar, Croatian association of civil engineers, Vol. 67, 2015, 975-983.

U ovom su radu predstavljeni rezultati usporedne analize stabilnosti pokosa

metodama granične ravnoteže i smanjenja parametara čvrstoće tla. Razmatrano

je nekoliko pokosa uzetih iz literature ili iz geotehničke prakse. Analiziran je

utjecaj vlačnog naprezanja, raspodijeljenog opterećenja, veličina konačnog

elementa i parametri modela na lokaciji te oblik kritičnog loma i odgovarajuće

vrijednosti faktora sigurnosti. Obje navedene metode daju slične rezultate ako se

ispravno primijene u odgovarajućim računalnim programima.

Ključne reči: granična ravnoteža, smanjenje parametara čvrstoće, dilatancija,

optimizacija, Bezijeova krivulja, vlačna zona.




D. Berisavljević, N. Šušić, D. Rakić, G. Hadži-Niković, Z. Berisavljević

ODREĐIVANJE VRSTE TLA I MIROSTRUKTURE IZ SDMT OPITA

Šesto naučno-stručno međunarodno savetovanje Geotehnički aspekti

građevinarstva, Savez građevinskih inženjera Srbije, 2015, 175-185.

U radu je prikazan dijagram za određivanje vrste tla i prisustva mikrostrukture u

tlu na osnovu rezultata SDMT opita. Vrsta tla se određuje iz veličina prelaznih

parametara (ID i KD) koji su rezultat mehaničkog DMT opita, a prisustvo

mikrostrukture se određuje na osnovu veličine maksimalnog modula smicanja

(G0) koji se dobija merenjem brzine smičućih talasa (Vs) u tlu korišćenem

seizmičkog modula prilikom izvođenja opita. Validacija dijagrama izvršena je

primenom rezultata dobijenih iz SDMT opita izvedenih na teritoriji Republike

Srbije i rezultata preuzetih iz literature.

Ključne reči: seizmički dilatometar (SDMT), mikrostruktura, maksimalni modul

smicanja (G0).

Z.Berisavljević, D.Rakić, N.Šušić, D.Berisavljević

DEFINISANJE PARAMETARA ČVRSTOĆE NA SMICANJE

HETEROGENE FLIŠNE STENSKE MASE - DEO I (INŽENJERSKO

GEOLOŠKE KARAKTERISTIKE)



Ovo je prvi deo studije pod nazivom: “Definisanje parametara čvrstoće na

smicanje heterogene flišne stenske mase”. U ovom delu prikazane su

inženjerskogeološke karakteristike heterogenih flišnih sedimenata okoline

Dimitrovgrada. Flišni sedimenti su veoma zastupljeni u našoj zemlji. Procenjuje

se da je oko 15-20% trase autoputnih koridora izvedeno, ili će biti izvedeno, u

flišu. Iz ovog razloga je veoma važno poznavati parametre smičuće čvrstoće fliša,

koji su neophodni za procenu stabilnosti kosina. Litološka heterogenost i

tektonska oštećenost čini ove materijale izuzetno nezahvalnim za rad. U

zavisnosti od procentualnog učešća pešćčara i siltita izdvojeno je pet bitno


različitih strukturnih tipova. GSI vrednost je određena na bazi kvantifikovanog

GSI dijagrama. Ispitivanje mineraloškog sastava pod mikroskopom omogućilo je

detaljniju karakterizaciju stenske mase.

Ključne reči: smičuća čvrstoća, GSI, SCR parameter.

Z.Berisavljević, D.Rakić, N.Šušić, D.Berisavljević

DEFINISANJE PARAMETARA ČVRSTOĆE NA SMICANJE

HETEROGENE FLIŠNE STENSKE MASE - DEO I (GEOTEHNIČKE

KARAKTERISTIKE)



Ovo je drugi deo studije pod nazivom: “Definisanje parametara čvrstoće na

smicanje heterogene flišne stenske mase”. Parametri smičuće čvrstoće definisani

su prema tri kriterijuma: Mohr-Coulomb-ovom, Hoek-Brown-ovom i nelinearnoj

anvelopi hiperboličkog tipa. Koristeći dostupne literaturne podatke određene su

gornja i donja granična vrednost parametara za generalnu flišnu sekvencu uz

pomoć nelinearne hiperboličke anvelope. Verifikacija parametara prikazana je u

posebnom radu i ovde nije detaljnije razmatrana.

Ključne reči: smičuća čvrstoća, GSI, hiperbolička anvelopa, LMA algoritam.


BITNO POBOLJŠAN PROIZVOD

ILI TEHNOLOGIJA (M84)

K. Đoković, L. Čaki, N. Šušić, G. Hadži-Niković

MODIFIKOVANI PIN-HOLE APARAT ZA ODREĐIVANJE

DISPERZIVNOSTI FINOZRNOG TLA

Odluka Instituta IMS br. 3-15670 od 31.12.2014.


T 230

BUILDING CONSTRUCTION T 230

VISOKA GRADNJA




M. Drpić, D. Ivanišević

PASIVNA ZAŠTITA OD POŽARA U GRAĐEVINARSTVU U OKVIRU

TEHNIČKE REGULATIVE U SRBIJI I U EVROPI

Građevinski materijali u savremenom graditeljstvu, Beograd, 2015, 11-18.

Pasivna zaštita od požara u građevinarstvu u skladu sa tehničkom regulativom u

Srbiji propisana je u okviru nekoliko pravilnika i SRPS standarda. U

međuvremenu, preuzet je veliki broj EN standarda i Evrokodova – kao SRPS EN.

Uloga nacionalne regulative u okviru pasivne zaštite od požara u građevinarstvu

je da se preuzmu opšti principi i da se uspostave specifična nacionalna pravila.

Ključne reči: pasivna zaštita od požara; građevinarstvo; nacionalna pravila.

M. Todorović

TEHNIČKI PREGLED OBJEKTA

IX međunarodno naučno-stručno savetovanje Ocena stanja, održavanje i

sanacija građevinskih objekata i naselja, Zlatibor, 2015, 509-516.

U radu je prikazana zakonska osnova za proceduru tehničkog pregleda objekata

kroz različite periode, od 1931.god. do danas važećeg Zakona o planiranju i

izgradnji i Pravilnika koji reguliše tehnički pregled objekta. Na jednom

konkretnom primeru iz prakse date su manjkavosti ili propusti istog kao i neki

predlozi za nova rešenja u ovoj oblasti.

Ključne reči: tehnički pregled, upotrebna dozvola, petlja Radnička.


T 450

METAL TECHNOLOGY,

METALLURGY,

METAL PRODUCTS

T450

TEHNOLOGIJA METALA,

METALURGIJA,

PROIZVODI OD METALA


RAD U VRHUNSKOM MEĐUNARODNOM

ČASOPISU (M21)

B. Međo, M. Rakin, N. Gubeljak, Y. Matvienko, M. Arsić, Ž. Šarkoćević,

A. Sedmak

FAILURE RESISTANCE OF DRILLING RIG CASING PIPES WITH

AN AXIAL CRACK

Engineering Failure Analysis, Elsevier, 2015.

Working conditions of casing pipes in drilling rigs can significantly influence the

initiation and development of damage in the material, and therefore also the safe

service of the entire system. In this work, an integrity assessment of a pipe with

initial defect (machined surface crack) is presented. The position of this defect is

on the external surface; unlike transport pipes, where internal surface is often

endangered due to the contact with the fluid, casing pipes are also often exposed

to damages at the external surface. A pipe segment exposed to internal pressure

is examined experimentally and numerically, using the finite element method.

Experimental setup included tracking of crack mouth opening displacement

(CMOD) values, as well as J integral. Criteria for pipe failure are determined on

the finite element (FE) models of the pipe; fracture initiation and plastic collapse

are considered as failure mechanisms. Several 3D models with different crack

sizes are evaluated. 2D plane strain models are also examined, to determine the

applicability limits of this simpli-fied approach. Integrity assessment criteria for

the analysed geometries are discussed. Assessment of fracture resistance of the

pipeline material is also considered in this work. Besides the standard SENB

specimens, Ring specimens cut from the pipe are tested, and the results are

compared. Both specimen geometries are modelled using local approach to

fracture, by application of the micromechanical Complete Gurson model (CGM),

devel-oped by Z.L. Zhang. It is shown that the Ring specimens have similar

fracture conditions under bending load as SENB specimens. Since they are much

simpler to fabricate from the pipe than standard specimens, it is concluded that

they can be used for assessment of fracture of the pipes with axial cracks.

Keywords: Cracked pipe, Finite element analysis, Pipe-ring specimen,

Micromechanical modelling.


Z. Odanović, M. Ristivojević, V. Milošević-Mitić

INVESTIGATION INTO THE CAUSES OF FRACTURE IN RAILWAY

FREIGHT CAR AXLE

Engineering Failure Analysis, 2015, Vol. 55, 169–181.

Railway axles are vital parts of railway. Their failure in the form of dynamic

fracture is commonly of disastrous outcomes for railway vehicles. Accordingly,

railway axles are designed to be highly reliable, while the maintenance system

requires regular inspection in terms of crack initiation. However, due to complex

exploitation conditions, complex stress state and multiple stress concentration,

railway axles often experience fatigue failures. This occurrence has been studied

in a large number of papers. This paper too sheds light on the causes of fracture

occurrence in the axle of railway freight car for coal transport in a thermal power

plant. Detailed analyses were conducted on the axle fracture surface and

mechanical properties. Also, microstructure of the axle material, as well as on

exploitation conditions and stress state was examined. Calculations indicated

that, apart from working load impact, the influence of press fit joints, especially

of the one between the labyrinth seal and the axle is of crucial importance for the

analysis of railway axle stress state. The entire numerical–experimental analysis

has shown that the considered axle failure was caused by inadequate

maintenance, insufficient axle strength and adverse stress state in the railway axle

critical cross-sections.

Keywords: railway engineering, stress concentrations, failurediagnostics, finite

element analysis, non-destructive testing

M. Burzić, M. Mango, J. Bernetić, Z. Burzić, M. Arsić

EFFECT OF VARIABLE LOAD ON CRACK INITIATION

MICROALLOYED STEEL S 690-QL

Metallurgy, Croatian Metallurgical Society, 2015, Vol. 54, No. 1, 55-58.

The accumulation of damage in the form of initiation and growth of micro-cracks

is the first stage of destruction that ends when the merger microcracks form macro

cracks. Cracks formed in the cycle number N=104-105 are the result of low cycle

fatigue. From the need to evaluate low cycle fatigue life was carried out to

investigate the low cycle fatigue microalloyed high-strength steel S690QL in the


heat-treated. The development of new methods of testing materials, and methods

relevant for assessing the behavior of structural material exploitation, enabled

better

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REVIEW NAUČNIH I STRUČNIH - Institut IMS rezultata 2015.pdfT 153 KERAMIČKI I PRAŠKASTI MATERIJALI..... 19 Rad u vrhunskom međunarodnom časopisu (M21)..... 20 Saopštenje sa međunarodnog