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Frontiers of Structural and Civil Engineering 2021年第5期15卷 1277-1291页

作者： ali NEMATZADEH Burcu AYTEKIN ali MARDANL-aghabaglou Department of Civil Engineering Bursa Uludag UniversityNilufer-Bursa 16059Turkey

In this paper,the effect of usage of the permeability reducing admixture(PRA)having different action mechanisms on hardened state properties of cementitious systems containing mineral additives is *** this aim,three commercial PRAs were used during *** effective parameters in the first and third PRAs were air-entraining and high-rate air-entraining,*** second one contained the insoluble calcium carbonate residue and had a small amount of the air-entraining *** mixes with binary and ternary cementitious systems were prepared by partially replacing cement with fly ash and *** hardened state properties of mortar mixtures such as compressive strength,ultrasonic pulse velocity,water absorption,drying shrinkage and freeze-thaw resistance were *** ternary cement-based mixture having both fly ash and metakaolin was selected as the most successful mineral-additive bearing mix in regard to hardened state *** this sense,PRA-B,with both insoluble residues and a small amount of air-entraining properties,showed the best performance among the mixtures containing *** combined use of mineral additive and PRA had a more positive effect on the properties of the mixes.

关键词： cementitious system mineral additive permeability reducing admixture mechanical properties durability performance

EFFECT OF POLYMER/CEMENT RATIO AND CURING REGIME ON POLYMER MODIFIED MORTAR PROPERTIES

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Journal of Green Building 2020年第3期15卷 177-193页

作者： Daniel Hatungimana Şemsi Yazıcı ali mardani-aghabaglou Department of Civil Engineering Eng.FacultyEge UniversityBornova-IzmirTurkey Department of Civil Engineering University of Burundi2700 BujumburaBurundi Civil Engineering Department Eng.FacultyBursa UludağUniversityNilüfer-BursaTurkey

Cement is the most consumed building material in the ***,cement manufacture is responsible for 5-7%of the world CO_(2)*** this paper,cement was partially replaced by styrene-butadiene rubber(SBR)polymeric latex in order to reduce cement ***,effects of SBR addition on the strength and physical properties of plain mortar exposed to three different curing regimes are *** different curing regimes were applied to the 40×40×160 mm prismatic mortar specimens:(Ⅰ):Specimens were cured in water until the test age(CW),(Ⅱ):after demoulding,specimens were immersed in water for 2 days and kept in ambient temperature until the time of the test(2DWA)and(Ⅲ)involved 2 days of water curing followed by 1 day in an oven at 50℃and subsequentely placing in ambient temperature until the test time(2W1OA).Results showed that combin-ing 2 days of water curing followed by ambient temperature curing(2DWA)along with 3%SBR polymer content showed good performance in terms of compressive strength,water absorption and void ***,a good performance in terms of flexural strength was observed by combining 2W1OA curing regime with 2%SBR ***,the detrimental effect of water curing regime(CW)in terms of compressive and flexural strength was also observed with the increase of SBR ratio.

关键词： SBR CO_(2)emissions curing regime strength

EFFECT OF RECYCLED CONCRETE AGGREGATE QUaliTY ON PROPERTIES OF CONCRETE

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Journal of Green Building 2020年第2期15卷 57-69页

作者： Daniel Hatungimana Semsi Yazıci ali mardani-aghabaglou Department of Civil Engineering Eng.FacultyEge UniversityBornova-IzmirTurkey Department of Civil Engineering University of Burundi2700 BujumburaBurundi Civil Engineering Department Eng.FacultyBursa UludağUniversityNilüfer-BursaTurkey

The possibility of the use of recycled aggregates from the construction industry in green concrete production is of increasing importance to reduce the negative environmental impact associated with construction and demolition *** objective of this study is to investigate the effect of recycled concrete aggregate(RCA)quality on the properties of hardened concrete properties such as compressive strength,splitting tensile strength,density,water absorption capacity and porosity accessible to *** RCA used in this study was obtained from the crushing of waste concrete with two different compressive strengths(LRCA obtained from the crushing of waste concrete having compressive strengths below 30 MPa and HRCA obtained from the crushing of waste concrete having compressive strengths above 30 MPa).The natural coarse limestone aggregate was 100%replaced with coarse LRCA and *** a result of the study,the use of 100%HRCA and%100 LRCA instead of limestone coarse aggregate in the concrete adversely affected its mechanical and physical *** addition,HRCA showed better performance in terms of compressive strength,tensile strength,water absorption and porosity compared to the use of ***,the percentage of adhered mortar on the surface of LRCA and HRCA was analyzed using a computerized micro tomography device,and it was found that the percentages of attached mortar and aggregates are 61%and 35.5%for LRCA,whilst the attached mortar and aggregate contents for HRCA are 45.9%and 53.7%,respectively.

关键词： X-Ray computed micro tomography recycled concrete aggregate adhered mortar

EFFECT OF STYRENE-BUTADIENE COPOLYMER(SBR)LATEX ON MECHANICAL AND TRANSPORT PROPERTIES OF PORTLAND CEMENT MORTAR

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Journal of Green Building 2020年第4期15卷 185-197页

作者： Daniel Hatungimana Şemsi Yazici Şevket Orhan ali mardani-aghabaglou Department of Civil Engineering Eng.Sciences FacultyUniversity of Burundi2700 BujumburaBurundi Department of Civil Engineering Eng.FacultyEge UniversityBornova-İzmirTurkey Department of Civil Engineering Eng.FacultyBursa UludağUniversityNilüfer-BursaTurkey

Portland cement is extensively used as a binder in concrete ***,with Portland cement production,5%of the natural resources used in this produc-tion are consumed,constituting 5-7%of the total CO_(2)*** order to mitigate the environmental problems associated with cement production,styrene-butadiene rubber latex was used as cement replacement up to 20%.In this study,compres-sive strength,flexural strength,unit weight,water absorption,open porosity,water sorptivity and the chloride ion permeability of Portland cement mortar mixtures modified by styrene-butadiene rubber(SBR)polymeric latex were *** this purpose,the sand/cement ratio and the water/cement ratio were kept constant as 3/1 and 0.5,*** addition to the control mixture containing no polymer,1,2,3,5,10 and 20 wt.%of cement was replaced with *** this way,seven mortar mixtures were *** curing(wet cure and dry cure)method was applied to the mortar *** showed that up to a 5%replacement level,it is possible to improve the mechanical properties of cement mortars with SBR latex ***,at a 10%and 20%replacement level,SBR had a signifi-cant detrimental effect on the mechanical properties of polymer modified ***,the transport properties decreased with the incorporation rate of SBR latex and the detrimental effect of SBR replacement was more pronounced in 20%SBR mortar mixtures.

关键词： mechanical properties transport properties SBR latex

PERFORMANCE OF STEEL MICRO FIBER REINFORCED MORTAR MIXTURES CONTAINING PLAIN,BINARY AND TERNARY CEMENTITIOUS SYSTEMS

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Journal of Green Building 2016年第4期11卷 109-130页

作者： ali mardani-aghabaglou Cihat Yüksel Hojjat Hosseinnezhad Kambiz Ramyar Department of Civil Engineering Eng.FacultyUludağUniversityNilüfer-BursaTurkey epartment of Civil Engineering Eng.FacultyEge UniversityBornova-İzmirTurkey

Steel micro fibers provide strengthening,toughening and durability improve-ment mechanisms in cementitious ***,there is not much data in the literature regarding how the extent of their effectiveness changes depend-ing on the type of matrix being *** clarifying this point,the influ-ence of a constant volumetric ratio(1%)of 6 mm long steel micro fibers on the performance of 5 mortar mixtures was investigated and were prepared using plain,binary and ternary cementitious systems.A total of 10 mixtures were *** mineral admixtures used in the study include silica fume(SF),metakaolin(MK)and a Class C fly ash(FA).While the replacement levels of SF and MK were 10%by weight of the total mass of the binder,this ratio was chosen as 30%for *** addition to the behavior of the mixtures under compressive,flexural and impact loads,abrasion,water absorption,chloride ion penetration,freez-ing-thawing resistance and drying shrinkage characteristics of the mixtures were *** results indicate that generally the refinement in the pore struc-ture of the matrix provided by mineral admixtures and the increase in resistance against growth and coalescence of micro-cracks provided by fibers produce a syn-ergistic effect and improve the investigated performances of the mixtures.

关键词： steel micro fiber mineral admixtures mechanical and transport properties durability performance

DURABILITY PERFORMANCE AND DIMENSIONAL STABILITY OF POLYPROPYLENE FIBER REINFORCED CONCRETE

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Journal of Green Building 2018年第2期13卷 20-41页

作者： ali mardani-aghabaglou SüleymanÖzen Muhammet Gökhan Altun Department of Civil Engineering Uludag UniversityNilufer-BursaTurkey

In this study, the durability performance and dimensional stability of polypropylene fiber reinforced concrete mixture were investigated. For this purpose, two series of concrete mixtures, including a 0.45 water/cement ratio was prepared both in the absence and presence of fiber. A CEMI 42.5 R type portland cement and crushed limestone aggregate with a maximum particle size of 25 mm were used. In addition to the control mixture without fiber, three different concrete mixtures were prepared by adding polypropylene fiber as 0.4%, 0.8% and 1% of total volume into the mixture. The time-dependent fresh state properties, strength, ultrasonic pulse velocity, transport properties, drying shrinkage and freeze-thaw resistance of concrete mixtures, sodium sulfate attack and abrasion were investigated comparatively. Test results demonstrated that utilization of fiber affected the fresh properties of the concrete mixtures negatively. However, the 0.8% fiber-bearing mixture showed the highest performance in terms of durability and dimensional stability. Beyond this utilization ratio, the durability performance of the concrete mixture was negatively affected. The risk of nonhomogeneous dispersion of the fiber in the mixture was relatively high in the excess fiber-bearing mixture. Consequently, with the formation of flocculation in the mixture the void ratio of concrete mixture increased.

关键词： fresh properties durability performance dimensional stability polypropylene fiber reinforced concrete

EFFECT OF CEMENT FINENESS ON PROPERTIES OF CEMENTITIOUS MATERIALS CONTAINING HIGH RANGE WATER REDUCING ADMIXTURE

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Journal of Green Building 2017年第1期12卷 142-167页

作者： ali mardani-aghabaglou Arif Emre Son Burak Felekoglu Kambiz Ramyar Department of Civil Engineering Eng.FacultyUludağUniversityNilüfer-BursaTurkey Department of Civil Engineering Eng.FacultyEge UniversityBornova-IzmirTurkey Department of Civil Engineering Eng.FacultyDokuz Eylul UniversityBuca-IzmirTurkey

The effect of cement fineness on the fresh state and rheological properties as well as compressive strength of cementitious systems was investigated.A CEM I 42.5R portland cement containing 7.92%C_(3)A and sulfate resisting cement containing 3.58%C(3)A were *** cements were ground to 4 different Blaine finenesses,ranging from 2800 to 4500 cm^(2)/*** the absence of water-reducing admixture,the water requirement of mixtures increased with an increase in the cement ***,the fresh state properties of the mixtures were affected ***,surprisingly,a reverse behavior was observed in the mixtures containing water-reducing admixtures,that is,an increase of the cement fineness increased the effectiveness of the admixture;consequently,the fresh state properties of the mixtures were *** seems to have been caused from the higher adsorption of the admixture on finer cement grains than on the coarser ***,as expected,the strength of the mortar and concrete mixtures increased along with the increase in cement fineness and its C3A content.

关键词： cement-admixture compatibility fresh properties rheological parameters

COMPARISON OF FRESH AND HARDENED PROPERTIES OF SELF-COMPACTING CONCRETE MIXTURE FROM DIFFERENT ASPECT RATIO OF STEEL FIBER VIEW POINT

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Journal of Green Building 2021年第1期16卷 115-138页

作者： Hassane Amidou Ouedraogo SüleymanÖzen Veysel Kobya Serkan Sagiroglu ali mardani-aghabaglou Department of Civil Engineering Eng.FacultyBursa UludağUniversityNilüfer-BursaTurkey

Self-compacting concrete(SCC)is a type of concrete which is frequently preferred in different applications due to its advantages such as its fluidity and transition in tight openings between steel reinforcing ***,it is vital that SCC maintains its fresh state characteristics when its transportation phase is taken into *** reinforced in SCC affects the properties of fresh concrete negatively while it had a positive effect on its dynamic *** this study,the effect of steel fibers having different aspect ratios on the time dependent fresh properties and mechani-cal properties of self-compacting concrete mixtures was *** addition to the control mixture without fiber,in the mixtures containing fiber,three different twin-hook steel fibers with aspect ratios of 54,64 and 50 were used as 0.6%of total *** all of the SCC mixtures,the water/cement ratio,cement dosage and slump-flow value were kept *** time dependent rheological properties of the mixtures were *** compressive,split-tensile and flexural strengths as well as fracture energy,the load deflection relation under flexural load and load-crack opening displacement,modulus of elasticity of SCC mixtures were also ***,the water absorption capacity and depth of penetration of water under pressure of mixtures were *** the basis of the results,the fiber utilization and its aspect ratio had no significant effect on compressive strength and modulus of elasticity of the SCC *** split-tensile,flexural strengths and fracture energy of SCC mixtures increased by using fiber;the permeability properties of SCC mixture increased by fiber utilization.

关键词： self consolidating concrete steel fiber aspect ratio fresh state properties mechanical properties.

DETERMINATION OF RADON AND NATURAL RADIOACTIVITY CONCENTRATION IN SOME BUILDING MATERIALS USED IN IZMIR,TURKEY

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Journal of Green Building 2020年第1期15卷 107-118页

作者： Daniel Hatungimana Caner Taşköprü Mutlu İçhedef Müslim Murat Saç Şemsi Yazıcı ali mardani-aghabaglou Department of Civil Engineering Eng.FacultyEge UniversityBornova-IzmirTurkey Institute of Nuclear Sciences Ege UniversityBornova-IzmirTurkey Department of Civil Engineering Eng.FacultyBursa UludağUniversityNilüfer-BursaTurkey Civil Engineering Department University of Burundi2700 BujumburaBurundi

The aim of this study is to determine the radon and natural radioactivity concentra-tions of some building materials and to assess the radiation hazard associated with those mortar materials when they are used in the construction of *** measurements were realized by using LR-115 Type 2 solid state nuclear track *** activity concentrations of these materials were found to vary between 130.00±11.40 and 1604.06±40.5 Bq m^(-3).The natural radioactivity in selected mortar materials was analyzed by using scintillation gamma *** activity concentrations for 226Ra,232Th and 40K for the studied mortar materials ranged from ND to 48.5±7.0 Bq kg^(-1),ND to 41.0±6.4 Bq kg^(-1)and ND to 720.4±26.8 Bq kg^(-1),*** equivalent activities,external and internal hazard indexes,gamma and alpha indexes and absorbed gamma dose rates were calculated to assess the radiation hazard of the natural radioactivity in studied *** calculated Raeq values of all samples were found to be lower than the limit of 370 Bq kg-1 set for building *** estimated hazard index values were found to be under the unity and the absorbed dose rate values were also below the worldwide average of 84 nGy h^(-1).

关键词： Radium activity solid state nuclear track detector hazard index absorbed dose rate

Effect of nonionic side chain length of polycarboxylate-ethe卜based high-range water-reducing admixture on properties of cementitious systems

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Frontiers of Structural and Civil Engineering 2020年第6期14卷 1573-1582页

作者： Sileyman OZEN Muhammet Gokhan ALTUN ali mardani-aghabaglou Kambiz RAMYAR Deparment of Civil Engineering Faculty of Enginering and Natural SciencesBursa Technical UniversinYildirim Bursa 16330Turkey Deparment of Civil Engineering Faculty of EngineeringBursa Uludag UniversityNilufer.Bursa 16059Turkey Department of Civil Engineering Faculty of EngineeringEge UniversityBornova-lzmir 35040Turkey

Despite the large variations in the behaviors of water-reducing admixtures upon changes in their structures,most previous reports on the cement-admixture compatibility did not provide suficient information on the structure of the ***,the evaluation and generalization of the reports on the cement-admixture compatibility are *** this study,three different polycarboxylate-ether-based water-reducing admixtures with the same free nonionic content,anionic/nonionic molar ratio,and main chain length and different side chain lengths were *** compatibility of these admixtures with a CEM I 42.5R-type cement was *** addition,an analysis of variance was performed on the experiment results to evaluate the contributions of the admixture type,admixture/cement ratio,and elapsing time to the Marsh funnel flow time,mini-slump,slump flow,and compressive *** water-reducing admixtures having long or short side chains reduced the initial flow characteristics of the cementitious ***,the admixture having the shortest side chain was better with regard to flow *** side chain length of the admixture did not have significant effects on the compressive strength and water absorption capacity of the mortar mixtures and mini-slump performances of the cement paste *** the behaviors of the admixtures in the cementitious systems,an optimal admixture side chain molecular weight is proposed.

关键词： water-reducing admixture side chain length cement paste fluidity compressive strength