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Mechanical properties and self-healing capacity of ultra high performance Fibre Reinforced Concrete with alumina nano-fibres: Tailoring Ultra High Durability Concrete for aggressive exposure scenarios Cement Concrete Comp. (IF 6.257) Pub Date : 2021-01-26 Estefania Cuenca; Leonardo D'Ambrosio; Dennis Lizunov; Aleksei Tretjakov; Olga Volobujeva; Liberato Ferrara
The effects of alumina nano-fibres are investigated in this paper on the mechanical performance of Ultra High Performance Fibre Reinforced Cementitious Concrete and their efficacy in enhancing the durability of the cementitious composite when exposed to extremely aggressive conditions, with main reference to the stimulated autogenous crack sealing and self-healing capacity. A tailored characterization
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Modified blended limestone-Portland cement binders: Evaluation of 4 different sodium silicates Cement Concrete Comp. (IF 6.257) Pub Date : 2021-01-11 J.L. Santana-Carrillo; D.E. Ortega-Zavala; O. Burciaga-Díaz; J.I. Escalante-Garcia
One-part blended cements with 65% limestone and 35% Portland cement (PC) were activated by 3–8%wt. of four powdered sodium silicates of different modulus SiO2/Na2O = 1–3.26. Pastes were cured at 20 °C for 180 days in dry and underwater conditions. The use of moduli <3.26 promoted quick setting and low strength of the pastes. The use of modulus = 3.26 showed the best results in terms of workability
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Design and performance of low shrinkage UHPC for thin bonded bridge deck overlay Cement Concrete Comp. (IF 6.257) Pub Date : 2021-01-22 Le Teng; Mahdi Valipour; Kamal H. Khayat
Ultra-high performance concrete (UHPC) has been successfully used for thin bonded overlay to rehabilitate concrete bridge decks. The performance of the overlay depends on shrinkage and bond to the substrate that can determine the service life of repair. In this study, pre-saturated lightweight sand (LWS) and CaO-based expansive agent (EA) were used to design low shrinkage non-proprietary UHPC. The
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Employing ultrasonic wave as a novel trigger of microcapsule self-healing cementitious materials Cement Concrete Comp. (IF 6.257) Pub Date : 2021-01-22 Na Xu; Zijian Song; Ming-Zhi Guo; Linhua Jiang; Hongqiang Chu; Chun Pei; Peipei Yu; Qingyang Liu; Ziming Li
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Dynamic compressive behaviour of hybrid basalt-polypropylene fibre-reinforced concrete under confining pressure: Experimental characterisation and strength criterion Cement Concrete Comp. (IF 6.257) Pub Date : 2021-01-22 Qiang Fu; Wenrui Xu; Dan Li; Ning Li; Ditao Niu; Lu Zhang; Bingbing Guo; Yongli Zhang
The dynamic compressive behaviour of hybrid basalt-polypropylene fibre-reinforced concrete (HBPRC) under confining pressure was investigated using a Hopkinson compression bar device with active confining pressure. The relationship between the pore structure and the dynamic compressive behaviour of HBPRC was discussed. The results indicate that the dynamic compressive behaviour of HBPRC under confining
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Effect of flow behavior and process-induced variations on shape stability of 3D printed elements – A review Cement Concrete Comp. (IF 6.257) Pub Date : 2021-01-21 Kavya Vallurupalli; Nima Farzadnia; Kamal H. Khayat
Successful implementation of extrusion-based 3D printing (3DP) of concrete requires knowledge of material flow behavior during pumping and extrusion and its influence on shape stability of printed elements. Limited emphasis exists on flow behavior and process-induced variations in material properties (rheology and composition) during printing. This paper delineates the effect of flow behavior and process-induced
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Effect of dispersed micro-fibers on tensile behavior of uncoated carbon textile-reinforced cementitious mortar after high-temperature exposure Cement Concrete Comp. (IF 6.257) Pub Date : 2021-01-16 Ngoc Hieu Dinh; Sang-Hyun Park; Kyoung-Kyu Choi
The mechanical and structural behavior of infrastructure and buildings under high-temperature environment is one of the major concerns in retrofit technologies. The present study aims to experimentally investigate the effectiveness of dispersed micro-fibers on the tensile behavior of uncoated carbon textile-reinforced mortar (TRM) after exposure to high temperatures. The main experimental parameters
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The influence of two types of alkali activators on the microstructure and performance of supersulfated cement concrete: mitigating the strength and carbonation resistance Cement Concrete Comp. (IF 6.257) Pub Date : 2021-01-18 Yang Zhou; Zechuan Peng; Luchuan Chen; Jiale Huang; Tao Ma
As a low-carbon cementitious material, the supersulfated cement (SSC) is composed of a thimbleful of cement clinkers and massive industry by-products, i. e: gypsum and slag. However, the concrete made from SSC suffers low strength, poor carbonation resistance, inferior frost resistance, etc. In such a scenario, two types of alkali activators (lactates and sodium hydroxyl) were employed to improve the
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Mechanical property and microstructure of quaternary phase paste blended with metakaolin Cement Concrete Comp. (IF 6.257) Pub Date : 2021-01-15 Wenwen Ding; Yongjia He; Linnu Lu; Fazhou Wang; Shuguang Hu
Calcium aluminate cement (CAC) shows some superior properties compared to Portland cement. However, the conversion of metastable hydrates limits the application of traditional CAC. This study reports a low cost and high strength quarternary phase (Q phase, Ca20Al26Mg3Si3O68)-metakaolin (MK) composite. The mechanical property and microstructure of this composite hydrated at ambient temperature were
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A generic model to determine crack spacing of short and randomly oriented polymeric fiber-reinforced strain-hardening cementitious composites (SHCC) Cement Concrete Comp. (IF 6.257) Pub Date : 2021-01-07 Junxia Li; Jian Weng; Zhitao Chen; En-Hua Yang
Crack spacing is an important property governing the tensile strain capacity of strain-hardening cementitious composites (SHCC). This paper presents a generic model to determine the crack spacing of short and randomly oriented polymeric fiber-reinforced SHCCs, which takes into account of the fiber/matrix interface chemical bond, the fiber/matrix interface slip-hardening behavior, and two-way fiber
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Effect of bauxite aggregate in cement composites on mechanical properties and resistance against high-velocity projectile impact Cement Concrete Comp. (IF 6.257) Pub Date : 2020-12-29 Fengling Zhang; Leong Hien Poh; Min-Hong Zhang
This paper investigates the effect of the bauxite sand and coarse aggregate on the quasi-static mechanical properties and resistance against high-velocity projectile impact of cement composites with 28-day compressive strengths from 34.2 to 197.2 MPa, in comparison to that of the siliceous sand and granite coarse aggregate. Mechanical properties investigated include compressive strength, elastic modulus
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Nanoindentation on micromechanical properties and microstructure of geopolymer with nano-SiO2 and nano-TiO2 Cement Concrete Comp. (IF 6.257) Pub Date : 2020-11-25 Zhiyu Luo; Wengui Li; Yixiang Gan; Xuzhen He; Arnaud Castel; Daichao Sheng
Fly ash-based geopolymers incorporated with 2% nano-SiO2 (NS)/nano-TiO2 (NT) particles were subjected to microstructural and statistical nanoindentation analysis. With the addition of both types of nanoparticles, the compressive strength of geopolymer and the micromechanical properties of N-A-S-H gel were increased. NS exhibited higher reinforcement effect than NT on macro-strength. However, NT more
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Free water effect on the dynamic compressive properties of mortar Cement Concrete Comp. (IF 6.257) Pub Date : 2021-01-11 Xihong Zhang; Yu-wen Chiu; Hong Hao; Jian Cui
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Development of self-stressing Engineered Cementitious Composites (ECC) Cement Concrete Comp. (IF 6.257) Pub Date : 2021-01-11 He Zhu; Duo Zhang; Yichao Wang; Tianyu Wang; Victor C. Li
While high ductility Engineered Cementitious Composites (ECC) have demonstrated effectiveness for infrastructure repair, the microcracking induced by the high material shrinkage may decrease the structural durability of ECC in aggressive environments. The objective of this research is to develop a self-stressing ECC, the expansion of which against the restraint of the repaired structure automatically
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Evolution of elastic and thermal properties of cementitious composites containing micro-size lightweight fillers after exposure to elevated temperature Cement Concrete Comp. (IF 6.257) Pub Date : 2021-01-11 Zhenglai Shen; Hongyu Zhou; Adam Brooks; Dominic Hanna
This paper studies the evolution of elastic and thermal properties of cementitious composites containing micro-size lightweight fillers after exposure to elevated temperatures (up to 800 °C). A multiscale investigation is carried out to study the thermal degradation of cementitious composite materials at multiple scale levels: at cement past level, the dehydration kinetics of cement hydrates (i.e.
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Influence of exposure conditions on expansion characteristics of lime-rich calcium sulfoaluminate-belite blended cement Cement Concrete Comp. (IF 6.257) Pub Date : 2021-01-11 Vaishnav Kumar Shenbagam; Rolands Cepuritis; Piyush Chaunsali
Expansive characteristics of calcium sulfoaluminate-belite (CSAB) cement can be harnessed for making shrinkage-compensating concrete. The level of expansion is dependent on several factors, such as the amounts of ye'elimite and calcium sulfate available in CSAB cement. Moreover, calcium sulfate from an external source can also influence the expansion characteristics by increasing the supersaturation
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Carbonation resistance study and inhomogeneity evolution of recycled aggregate concretes under loading effects Cement Concrete Comp. (IF 6.257) Pub Date : 2021-01-07 Renjie Mi; K.M. Liew; Ganghua Pan; Tong Kuang
Carbonation-load coupling effects can aggravate the inhomogeneity of recycled aggregate concrete (RAC) which contains old attached mortar (OAM) and new added mortar (NAM). In this study, these mortars are first distinguished using an iron oxide. Afterwards, accelerated carbonation coupled with four-point bending effects is applied on the RAC samples, and the carbonation depths in compressive, load-free
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Flexural behavior of carbon fiber-reinforced concrete beams under impact loading Cement Concrete Comp. (IF 6.257) Pub Date : 2021-01-06 Zhuoran Wang; Gang Ma; Zhihong Ma; Yu Zhang
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Performance evaluation of bacterial self-healing rigid pavement by incorporating recycled brick aggregate Cement Concrete Comp. (IF 6.257) Pub Date : 2020-12-28 Babar Saleem; Arshad Hussain; Afaq Khattak; Azam Khan
Concrete is the most widely used construction material in the world. Surely, it is extensively employed in the construction of rigid pavements. Repetitive loads on the pavement cause cracks which allow the ingress of harmful compounds and thus reduce the durability of concrete. Hence, this research presents an ecofriendly solution to impart self-healing capability to concrete by using bacteria as a
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Effect of mixing method on the performance of alkali-activated fly ash/slag pastes along with polycarboxylate admixture Cement Concrete Comp. (IF 6.257) Pub Date : 2021-01-03 Yazan Alrefaei; Yan-Shuai Wang; Jian-Guo Dai
The addition sequence of raw materials during mixing is one factor that affects the fresh and hardened properties of ordinary Portland cement (OPC). Similar to OPC, the properties of alkali-activated materials (AAMs) may be susceptible to the mixing procedure, yet the mixing procedure's effect is still unclear. This research aims to investigate how different mixing procedures affect the fresh and hardened
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Diffusivity of cement paste via a continuum-based microstructure and hydration model: influence of cement grain shape Cement Concrete Comp. (IF 6.257) Pub Date : 2021-01-05 Zhigang Zhu; Wenxiang Xu; Huisu Chen; Yuan Wang; Xiaofan Gou; Lin Liu; Yue Gu
A microstructure-guided diffusivity model of cement paste is devised to explore the dependence of the relative diffusivity on the microstructure evolutions of cement paste from fresh state via non-spherical cement particles hydration to hardened state. The microstructure-guided diffusivity model contains three main components: (1) the microstructure of fresh cement paste is generated to simulate the
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Rheo-morphological investigation of Reynolds dilatancy and its effect on pumpability of self-consolidating concrete Cement Concrete Comp. (IF 6.257) Pub Date : 2020-12-24 Masoud Hosseinpoor; Baba-Issa Ouro Koura; Ammar Yahia
Reynolds dilatancy is one of the main mechanisms responsible for the lubrication layer (LL) formation during pumping of self-consolidating concrete (SCC). In this study, the effect of morphological characteristics of coarse aggregate on Reynolds dilatancy of 30 different SCC mixtures was investigated. The Reynolds dilatancy measurements were carried out using a coaxial-cylinders tribometer. New methodology
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Carbonation of calcium sulfoaluminate cement blended with blast furnace slag Cement Concrete Comp. (IF 6.257) Pub Date : 2021-01-04 Joonho Seo; Seonhyeok Kim; Solmoi Park; H.N. Yoon; H.K. Lee
The present study investigated the carbonation of calcium sulfoaluminate (CSA) cement blended with blast furnace slag. Paste samples were prepared by substituting CSA cement with slag at dosages of 0, 30, 50, and 70 wt%. The samples were carbonated for 28 days at a CO2 concentration of 3% after a sufficient pre-curing period. The test results indicated that slag incorporation did not affect the phase
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Prediction of the autogenous shrinkage and microcracking of alkali-activated slag and fly ash concrete Cement Concrete Comp. (IF 6.257) Pub Date : 2020-12-24 Zhenming Li; Tianshi Lu; Yun Chen; Bei Wu; Guang Ye
This study aims to predict the autogenous shrinkage of alkali-activated concrete (AAC) based on slag and fly ash. A variety of analytical and numerical models are available for the prediction of autogenous shrinkage of ordinary Portland cement (OPC) concrete, but these models are found to show dramatic discrepancies when applied for AAC due to the different behaviours of these two systems. In this
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Low hydration exothermic well cement system: The application of energy storage microspheres prepared by high-strength hollow microspheres carrying phase change materials Cement Concrete Comp. (IF 6.257) Pub Date : 2020-12-23 Yuhuan Bu; Rui Ma; Huajie Liu; Chuanhua Ma; Xuezhan Zhao
An energy storage microsphere, prepared by encapsulating phase change materials in high-strength hollow microsphere, was proposed in this paper. The research objective was designed to utilise energy storage microspheres (ESM) in the cement mixture to achieve low hydration exothermic, without negatively affecting other properties. In this study, ESM were prepared and the difference between sealed and
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Effect of improved autogenous mortar self-healing in the alkali-aggregate reaction Cement Concrete Comp. (IF 6.257) Pub Date : 2020-12-28 Guilherme S. Munhoz; Mateus E.G. Dobrovolski; Eduardo Pereira; Ronaldo A. Medeiros-Junior
This article evaluated the effect of improved autogenous mortar self-healing in the alkali-aggregate reaction (AAR). Prismatic mortar specimens were cast with different contents of polypropylene microfiber and crystalline admixture. The crack-induction method (for subsequent self-healing) was the AAR accelerated mortar bar test itself. After AAR-testing, the specimens were submitted to wetting and
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Meso-scale mechanical deterioration of mortar subjected to freeze thaw cycles and sodium chloride attack Cement Concrete Comp. (IF 6.257) Pub Date : 2020-12-28 Yi Wang; Junhui Li; Tamon Ueda; Dawei Zhang; Jun Deng
This paper aims to quantitatively examine the effect of sodium chloride (NaCl) on the frost-induced mechanical deterioration of mortar. After the freeze thaw cycles (FTCs), the mechanical properties of sealed specimens (70 × 30 × 5 mm) saturated with NaCl solutions were investigated. As found, the specimens with a lower water-to-cement ratio (W/C) show no clear reductions in their flexural strength
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Effect of thermal treatment of SiC nanowhiskers on rheological, hydration, mechanical and microstructure properties of Portland cement pastes Cement Concrete Comp. (IF 6.257) Pub Date : 2020-12-28 Nagilla Huerb de Azevedo; Paulo Ricardo de Matos; Philippe J.P. Gleize; Andrea Murillo Betioli
The properties of silicon nanowhiskers suggest that they are ideal candidates for high-performance cementitious composites. In this study, we used SiC nanowhiskers (SiC NWs) without treatment and treated them at 500 °C. The SiC NWs were dispersed in water, and the corresponding effects of dispersion at 0.25, 0.50, and 1.00 wt% of cement were investigated. The rheological properties and fluidity of
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Experimental study on mechanical property and microstructure of cement mortar reinforced with elaborately recycled GFRP fiber Cement Concrete Comp. (IF 6.257) Pub Date : 2020-12-28 Boyu Zhou; Mo Zhang; Li Wang; Guowei Ma
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Modeling the fire-induced spalling in concrete structures incorporating hydro-thermo-mechanical stresses Cement Concrete Comp. (IF 6.257) Pub Date : 2020-12-26 Venkatesh Kodur; Srishti Banerji
This paper presents a numerical approach for predicting spalling in concrete structural members under fire conditions. The proposed approach evaluates spalling by taking into account the stresses generated due to pore pressure, thermal gradients, and structural loading under fire conditions. This approach is incorporated as a spalling sub-model into a macroscopic finite element based model that is
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Enhanced effect of carbon nanofibers on heating efficiency of conductive cementitious composites under ohmic heating curing Cement Concrete Comp. (IF 6.257) Pub Date : 2020-12-21 Weichen Tian; Yushi Liu; Beimeng Qi; Wei Wang
Ohmic heating (OH) curing method has been proved to cure conductive fibers enhanced cementitious composites by electric-heating conversion under ultralow temperature, and this curing effect depends greatly on the heating efficiency. This paper presents a novel idea of utilizing carbon nanofibers (CNFs) to regulate and control the heating efficiency of carbon fibers (CFs) enhanced cementitious composites
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Characterization of microstructural damage evolution of freeze-thawed shotcrete by an integrative micro-CT and nanoindentation statistical approach Cement Concrete Comp. (IF 6.257) Pub Date : 2020-12-25 Mengxin Liu; Dongxu Liu; Pizhong Qiao; Lizhi Sun
It is crucial to investigate the evolution of microstructure to understand the deterioration mechanisms of shotcrete under cyclic freezing and thawing (F-T). In this study, nanoindentation and X-ray micro-CT techniques are integrated to characterize microstructural damage of shotcrete and its evolution due to F-T actions. An integrated statistical method of nanoindentation and micro-CT (NI-MCT) is
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Use of magnesium-silicate-hydrate (M-S-H) cement mixes in 3D printing applications Cement Concrete Comp. (IF 6.257) Pub Date : 2020-12-25 Biranchi Panda; Cem Sonat; En-Hua Yang; Ming Jen Tan; Cise Unluer
This study focused on the development of 3D printed building components incorporating MgO–SiO2 binders. The effects of parameters such as MgO/SiO2 and water/binder ratios and superplasticizer dosage were evaluated to produce 3D printable MgO–SiO2 binders. The assessment of rheological and mechanical properties, which led to an optimum mix that satisfied the printability criteria, was supported by microstructural
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Development and testing of fast curing, mineral-impregnated carbon fiber (MCF) reinforcements based on metakaolin-made geopolymers Cement Concrete Comp. (IF 6.257) Pub Date : 2020-12-17 Jitong Zhao; Marco Liebscher; Albert Michel; Dominik Junger; Ana Carolina Constâncio Trindade; Flávio de Andrade Silva; Viktor Mechtcherine
Mineral-impregnated, carbon fiber composites (MCF) are a promising alternative to conventional concrete reinforcements. For the efficient industrial production of MCF, sufficient processing time for the impregnation suspension must be ensured. In the present investigation, a metakaolin-made geopolymer (GP) has been developed and tested for this purpose. The impregnation of carbon-fiber yarns was performed
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Pore structure, adsorption, and water absorption of expanded perlite mortar in external thermal insulation composite system during aging Cement Concrete Comp. (IF 6.257) Pub Date : 2020-12-16 Houren Xiong; Kelong Yuan; Jinming Xu; Minjie Wen
Pore structure is an important factor that affects both vapor adsorption and water absorption performances of the expanded perlite insulation mortar. This study aims to explore the change in the pore structure of the expanded perlite insulation mortar in heat-rain cycles and investigate the effects on capillary water absorption and vapor adsorption performances. The expanded perlite insulation mortar
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Damping characteristics of PVA fiber-reinforced cementitious composite containing high-volume fly ash under frequency-temperature coupling effects Cement Concrete Comp. (IF 6.257) Pub Date : 2020-12-24 Wu-Jian Long; Hao-Dao Li; Liu Mei; Weiwen Li; Feng Xing; Kamal H. Khayat
The service life of concrete structures is often threatened by unfavorable dynamic loads. Optimizing the material damping can improve the vibration damping of the structure. In this study, a polyvinyl alcohol fiber-reinforced high-volume fly ash (PVA-HVFA) cementitious composite was developed with high damping characteristics and moderate mechanical properties. The coupling effects of frequency and
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The fire resistance of high-strength concrete containing natural zeolites Cement Concrete Comp. (IF 6.257) Pub Date : 2020-12-15 Alexandra R.L. Kushnir; Michael J. Heap; Luke Griffiths; Fabian B. Wadsworth; Alessio Langella; Patrick Baud; Thierry Reuschlé; Jackie E. Kendrick; James E.P. Utley
More sustainable and environmentally friendly concretes are essential to reduce the climatic and environmental impact of the growing demand for concrete to fuel urban sprawl. This manuscript reports on an experimental study designed to test the fire resistance of one such concrete, prepared to contain natural zeolite-bearing tuff. The fire resistance of concretes containing natural zeolites has received
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Effect of alkali reactions on the rheology of one-part 3D printable geopolymer concrete Cement Concrete Comp. (IF 6.257) Pub Date : 2020-12-14 Shravan Muthukrishnan; Sayanthan Ramakrishnan; Jay Sanjayan
Yield strength development of 3D printable concrete by the early age activation reactions plays a vital role in the printability of geopolymer concrete. This study presents a rheo-chemical approach to investigate the early age strength development due to alkali reactions for the formulation of suitable 3D printable one-part geopolymer concrete. The influence of design parameters, including activator
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3D printed mesh reinforced geopolymer: Notched prism bending Cement Concrete Comp. (IF 6.257) Pub Date : 2020-12-07 Henrique A. Santana; Nilson S. Amorim Júnior; Daniel V. Ribeiro; Marcelo S. Cilla; Cleber M.R. Dias
Geopolymer binders, having high mechanical performance and associated low carbon dioxide (CO2) emission, are a promising alternative to Portland cement. However, the brittle fracture of geopolymer matrices may cause catastrophic failure. In this context, seeking to unite the concepts of textile concrete technology and additive manufacturing, this work proposes the development of composites of geopolymer
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Mesoscale simulation of pull-out performance for corroded reinforcement with stirrup confinement in concrete by 3D RBSM Cement Concrete Comp. (IF 6.257) Pub Date : 2020-12-09 Kumar Avadh; Punyawut Jiradilok; John E. Bolander; Kohei Nagai
The confining effect of concrete cover and stirrups reduces the rate of bond deterioration due to corrosion. However, the large dispersion in recorded experimental data makes it difficult to clearly separate the influence of cover depth and stirrup confinement on bond degradation. This study utilises the discrete 3D Rigid Body Spring Model (RBSM) to conduct a meso-scale investigation regarding the
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Exploring the coupled mechanism of fibers and bacteria on self-healing concrete from bacterial extracellular polymeric substances (EPS) Cement Concrete Comp. (IF 6.257) Pub Date : 2020-12-13 Yilin Su; Chunxiang Qian; Yafeng Rui; Jianhang Feng
With the development of the sustainable cement industry, the self-healing properties of concrete have received widespread attention. In many studies, both microorganisms and fibers play an important role in promoting the self-healing ability of concrete. In particular, some recent studies have tried to load microorganisms with fibers for improving the self-healing ability of concrete; and these studies
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Cement nanocomposites containing montmorillonite nanosheets modified with surfactants of various chain lengths Cement Concrete Comp. (IF 6.257) Pub Date : 2020-12-14 Jeong-A Oh; Yan Zhuge; Sherif Araby; Ruoyu Wang; Huimin Yu; Wei Fan; Ming Liu; Sang-Heon Lee; Md Joherul Alam; Jun Ma
To investigate the dispersion of montmorillonite (MMT) nanosheets in cement, MMT was modified with three organic surfactants of various alkyl chain lengths (C1-OMMT, C10-OMMT and C16-OMMT) and then compounded with cement. Of all nanocomposites, the one containing 0.5 wt% of C10-OMMT exhibited the most significant enhancement in compressive strength by 11.2% and in the hydration degree by 11% with low
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Effect of iron (III) oxide concentration on the performance of meta-resonators embedded in cementitious matrix Cement Concrete Comp. (IF 6.257) Pub Date : 2020-12-08 Yee Loon Sum; Vanessa Rheinheimer; Boon Hee Soong; Paulo J.M. Monteiro
Efforts are currently underway to improve the performance of small electric antennas and resonator-based antennas embedded in the civil infrastructure. One of the main limitations of these small antennas is that they have narrow bandwidths which limit their use when embedded in concrete. The present work shows that by changing the amount of iron (III) oxide microparticles in a cementitious matrix,
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Improving the utility of MIP analysis for cementitious systems through Gaussian process regression modeling to predict electrical resistivity Cement Concrete Comp. (IF 6.257) Pub Date : 2020-11-19 Caitlin M. Tibbetts; Benjamin E. Watts; Christopher C. Ferraro; Ethan D. Huber
Durability of concrete is a key design parameter and is strongly related to the penetrability of the cementitious binder matrix. This research evaluated methods to estimate the durability of concrete in service, using different procedures to characterize the penetrability of concrete, mortar, and paste. Mercury intrusion porosimetry (MIP) was compared to several standardized testing methods (surface
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Evaluating the thermal efficiency of microencapsulated phase change materials for thermal energy storage in cementitious composites Cement Concrete Comp. (IF 6.257) Pub Date : 2020-12-07 Mohammad Balapour; Angela W. Mutua; Yaghoob Farnam
Microencapsulated phase change materials (MCPM) have been shown to be a promising material that can be used in cementitious composites for thermal energy storage. This paper evaluates the thermal efficiency of MPCM incorporated in the cementitious composite and quantitatively identifies the influential mechanical and chemical damages that can lead to reductions in thermal efficiency of MPCM with melamine
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Progress, current thinking and challenges in geopolymer foam concrete technology Cement Concrete Comp. (IF 6.257) Pub Date : 2020-11-29 K. Dhasindrakrishna; Kirubajiny Pasupathy; Sayanthan Ramakrishnan; Jay Sanjayan
Geopolymer foam concrete (GFC) has attracted significant research interest in various fields, thanks to their porous structure which brings the inherent merits of lightweight, acoustic and thermal insulation, and fire resistance. This review is focussed on three primary functional properties of GFC, namely mechanical properties (compression and flexural strengths), serviceability (thermal conductivity
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The long-term failure mechanisms of alkali-activated slag mortar exposed to wet-dry cycles of sodium sulphate Cement Concrete Comp. (IF 6.257) Pub Date : 2020-12-09 Qing Li; Xinyuan Li; Kai Yang; Xiaohong Zhu; Juan Pablo Gevaudan; Changhui Yang; Muhammed Basheer
This study investigates the long-term (570 days) performance of alkali-activated slag (AAS) mortar materials exposed to combined wet-dry cycles and sodium sulphate solutions (i.e. 5 wt% and 10 wt%). Physical and mechanical characteristics of AAS mortars (i.e. visual appearance, compressive/flexural strength, mass change, capillary porosity, water sorptivity) as well as mineralogical and chemical parameters
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Co-disposal of MSWI fly ash and spent caustic through alkaline-activation consolidation Cement Concrete Comp. (IF 6.257) Pub Date : 2020-11-30 Xiang Tian; Feng Rao; Carlos Alberto León-Patiño; Shaoxian Song
This work investigates spent caustic as an alkaline activator for the consolidation of municipal solid waste incineration (MSWI) fly ash through the alkaline activation process. The effects of comparable alkalinity of NaOH solution and spent caustic, and the addition of blast furnace slag (BFS) on consolidation MSWI fly ash were investigated. Compressive strength measurement for alkali-activated MSWI
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Meso-scale modelling of static and dynamic tensile fracture of concrete accounting for real-shape aggregates Cement Concrete Comp. (IF 6.257) Pub Date : 2020-12-03 Sadjad Naderi; Mingzhong Zhang
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Determining the freeze-thaw performance of mortar samples using length change measurements during freezing Cement Concrete Comp. (IF 6.257) Pub Date : 2020-11-14 Rita Maria Ghantous; Mehdi Khanzadeh Moradllo; Hope Hall Becker; M. Tyler Ley; W. Jason Weiss
The Freeze-thaw (FT) performance of cementitious materials is dependent on the degree of saturation (DOS). It has been proposed that FT damage can occur during freezing when the DOS is greater than a critical DOS (DOSCR). In a previous study, a systematic methodology has been developed to determine the DOSCR of cement paste samples using high precision length change measurements during freezing and
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Beneficial and detrimental effects of molybdate as an inhibitor on reinforcing steels in saturated Ca(OH)2 solution: Spontaneous passivation Cement Concrete Comp. (IF 6.257) Pub Date : 2020-11-28 Miao Wu; Haifeng Ma; Jinjie Shi
The influence of molybdate on the spontaneous passivation of the low-carbon steel and a novel 10% Cr steel in saturated Ca(OH)2 solution was investigated in this study. The results show that molybdate promotes spontaneous passivation of low-carbon steel at the early exposure time and its passivation capability can be further enhanced with increasing concentration of molybdate. Unexpectedly, when adding
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Effect of relative humidity and porosity on the logarithmic creep of the layered C–S–H minerals tobermorite and jennite Cement Concrete Comp. (IF 6.257) Pub Date : 2020-11-26 Zhao Chen; Luca Sorelli
Tobermorite is a natural mineral found in the microstructure of special concretes, such as autoclaved concrete and oil well cement, and along with jennite has been extensively studied for their analogy to the layered atomic structure of C –S –H. By employing creep microindentation tests, which allow measuring the logarithmic creep, this work aims at further investigating the viscoelastic behavior of
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Influence of steel slag on the properties of alkali-activated fly ash and blast-furnace slag based fiber reinforced composites Cement Concrete Comp. (IF 6.257) Pub Date : 2020-11-23 Yujing Zhao; Tao Shi; Liying Cao; Lili Kan; Min Wu
This work focuses on studying the alkali-activated fiber reinforced composites (AAFRCs) with steel slag (SS) as a precursor material. Apart from finding a sustainable way to reuse the enormous amount of industrial by-product SS, it is also the aim to develop material systems with excellent ductility that may be used in a variety of applications. Using SS as a partial replacement (0%–25%) for fly ash
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Anisotropic electrical and piezoresistive sensing properties of cement-based sensors with aligned carbon fibers Cement Concrete Comp. (IF 6.257) Pub Date : 2020-11-21 Jinxia Xu; Tianjiao Yin; Yang Wang; Liyuan Liu
This paper aims to examine the effect of orientation and alignment of carbon fibers contained in a cement-based sensor under a magnetic field (MF) on the electrical and piezoresistive sensing properties of the resulting cement-based composite. The electrical conductivity and piezoresistive responses in two directions of aligned carbon fiber cement-based composites, i.e., parallel and perpendicular
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Macro–meso–micro experimental studies of calcined clay limestone cement (LC3) paste subjected to elevated temperature Cement Concrete Comp. (IF 6.257) Pub Date : 2020-11-19 Run-Sheng Lin; Yi Han; Xiao-Yong Wang
In this study, the macro properties (residual compressive strength), meso properties (mesoscopic images), and micro properties (reaction products and pore structures) of paste specimens with various limestone and calcined clay contents at elevated temperatures (20, 300, 550, and 900 °C) are experimentally investigated. According to the experimental results, (1) the strengths of all samples increase
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Iron mineral admixtures improve the sulfuric acid resistance of low-calcium alkali-activated cements Cement Concrete Comp. (IF 6.257) Pub Date : 2020-11-19 Juan Pablo Gevaudan; Briana Santa-Ana; Wil V. Sruba
We investigated the sulfuric acid resistance of low-calcium alkali-activated materials (i.e., geopolymers) supplemented with an iron mineral admixture (i.e., hematite). Geopolymers without and with 5% hematite were produced at two alkali contents (Na:Al = 0.86 and 1.39). Acid degradation reactions were comprehensibly studied through three replenishes of acid. Results demonstrate that hematite is chemically
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Combined impact of carbonation and crack width on the Chloride Penetration and Corrosion Resistance of Concrete Structures Cement Concrete Comp. (IF 6.257) Pub Date : 2020-10-13 Abbas S. AL-Ameeri; M. Imran Rafiq; Ourania Tsioulou
Chloride-induced corrosion of steel rebar embedded in concrete is one of the major concerns influencing the durability of reinforced concrete structures. It is widely recognized that the carbonation in concrete affects the chloride diffusivity and accelerates chloride-induced reinforcement corrosion. The service load-related cracks also have a dominant influence on reinforcement corrosion. This study
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Sprayable engineered cementitious composites (ECC) using calcined clay limestone cement (LC3) and PP fiber Cement Concrete Comp. (IF 6.257) Pub Date : 2020-11-10 He Zhu; Kequan Yu; Victor C. Li
Sprayable engineered cementitious composites (ECC) has demonstrated in field applications as a promising repair material. However, the large cement dosage that leads to a high carbon footprint and potential restrained shrinkage cracking suggests needed improvements. In this study, a sprayable ECC was developed using calcined clay limestone cement (LC3), calcium sulfoaluminate (CSA) expansive additive
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Extrusion-based concrete 3D printing from a material perspective: A state-of-the-art review Cement Concrete Comp. (IF 6.257) Pub Date : 2020-10-22 Manu K. Mohan; A.V. Rahul; Geert De Schutter; Kim Van Tittelboom
This paper provides a comprehensive review of the material behaviour for extrusion-based concrete 3D printing spanning from the early age to long-term performance. We begin with a discussion on the recent progress on the understanding of early-age behaviour. Following this, the mechanical response in the hardened state, and the different strategies to introduce reinforcement are reviewed. Finally,
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Relationship between oxygen content of graphene and mechanical properties of cement-based composites Cement Concrete Comp. (IF 6.257) Pub Date : 2020-10-23 Luca Lavagna; Daniele Massella; Emanuele Priola; Matteo Pavese
Cement composites were realized containing graphene-based materials having different oxygen content (from 0 to 45%). It was found that the polarity of the reinforcement influences both the dispersion in water and the chemical interaction with the hydrated cement matrix, and thus the mechanical performance of the composites. In particular, the reinforcements with the highest oxygen content result aggregated
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