Review
Construction & Building Technology
Shazim Ali Memon, Zere Bekzhanova, Aray Murzakarimova
Summary: This paper discusses the differences between recycled concrete aggregate (RCA) and natural aggregate (NA) in terms of physical, mechanical, and chemical properties. It also covers methods for improving the interfacial transition zone (ITZ) and adherent mortar regions of RCA. The review concludes that carbonation treatment is the most efficient and sustainable method for enhancing RCA.
Article
Construction & Building Technology
Yanxing Han, Sijie Shao, Bodong Fang, Tao Shi, Baiwei Zhang, Xingyu Wang, Xingyu Zhao
Summary: This study investigated the chloride penetration resistance of multi-walled carbon nanotubes (MWCNTs)-reinforced concrete using the rapid chloride migration (RCM) coefficient and immersion methods. The results showed that the chloride diffusion depth and diffusion coefficient of 28-day concrete decreased by 25.7% and 19.1%, respectively, when the MWCNTs content reached 0.15%. The concentration of free chloride ions in MWCNTs-reinforced concrete was consistently lower than the control group in the four different ages of natural immersion. The incorporation of MWCNTs enhanced the concrete's chloride ion penetration resistance by reducing the concentration of chloride ions and the diffusion coefficient, and the interface effect range decreased with the increase in MWCNTs content. The microhardness of the interface increased by 13.2% when the MWCNTs content reached 0.15%. SEM and MIP tests revealed that MWCNTs bridged and filled cracks, compacted the pore structure, and improved the microstructure and chloride ion penetration resistance of concrete.
JOURNAL OF BUILDING ENGINEERING
(2023)
Article
Construction & Building Technology
Xiaoshuang Shi, Ying Feng, Yuhao Zhang, Yanpeng Su
Summary: This study investigates the effects of sulfate attack on the structure and performance of geopolymer recycled concrete (GRC). The results show that GRC with 30% recycled aggregate substitution rate has the best resistance to sulfate attack. Moreover, it is found that the recycled aggregate contributes to the excellent resistance of GRC to sulfate attack.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
Jiarong Shen, Wenyu Li, Qianjun Xu, Shouguang Wang, Peng Qian
Summary: This study presents an experimental and statistical analysis of the initial microcrack characteristics in concrete, focusing on the interfacial transition zone (ITZ) and cement paste. Using image recognition algorithms and statistical analysis, the different behaviors of each type of microcrack are identified, and their effects on the microstructure and macroproperties of concrete are deduced. The findings provide an experimental and theoretical foundation for evaluating the characteristics of microcracks in concrete.
JOURNAL OF MATERIALS IN CIVIL ENGINEERING
(2023)
Article
Construction & Building Technology
Sang-Yeop Chung, Ji-Su Kim, Paul H. Kamm, Dietmar Stephan, Tong-Seok Han, Mohamed Abd Elrahman
Summary: The study utilized three-dimensional micro-CT to investigate the interfacial transition zone (ITZ) in concrete, revealing that the pore and solid characteristics of ITZ can effectively be examined using this method.
JOURNAL OF MATERIALS IN CIVIL ENGINEERING
(2021)
Article
Mechanics
Xun Xi, Ziqing Yin, Shangtong Yang, Chun-Qing Li
Summary: This study predicts the fracture properties of the ITZ in concrete using artificial neural network (ANN) method, showing that the trained ANN model performs well and has good agreement with experimental results. It is found that the randomness of aggregates has minimal effect on the predicted ITZ tensile strength but slightly bigger effect on the predicted ITZ fracture energy.
ENGINEERING FRACTURE MECHANICS
(2021)
Article
Construction & Building Technology
Pushkraj Anil Nemade, Dinakar Pasla, Anush K. Chandrappa
Summary: The rapid growth of infrastructure has led to the depletion of natural aggregates in cement concrete. Efforts have been made to replace natural aggregates with industrial by-products, such as steel slag aggregates. However, the utilization of Linz Donawitz (LD) slag aggregates in concrete is very limited due to their expansive nature, which may result in durability issues. In this study, the compressive strength and durability of concrete with 100% LD slag coarse aggregate were investigated. The results showed that LD slag concrete exhibited higher strength, lower permeability, and lower water absorption compared to control concrete, indicating enhanced durability.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Review
Construction & Building Technology
Yashar Asghari, Seyed Esmaeil Mohammadyan-Yasouj, Seyed Saeid Rahimian Koloor
Summary: Self-consolidating concrete (SCC), which requires no vibration and has good filling ability, offers advantages over regular concrete in terms of construction time, labor cost, and noise pollution. The production of cement, due to population growth and increased demand, leads to higher carbon dioxide (CO2) emissions and air pollution. Supplementary Cementitious Materials (SCMs), such as Metakaolin (MK), have been proposed as alternatives to reduce cement usage and CO2 emissions. This study reviews the use of MK in SCC, examining its effects on fresh, hardened, and durability properties, as well as microstructure, and provides comprehensive data on the behavior of SCCs incorporating MK.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
H. Momotaz, M. M. Rahman, M. R. Karim, Y. Zhuge, X. Ma, P. Levett
Summary: This paper investigates the effect of using recycled aggregates on the mechanical and chemical properties of concrete. It is observed that tyre-derived aggregates form weaker bonds with cement paste, and the interfacial transition zone (ITZ) has a considerably lower elastic modulus than cement paste. Many nano-pores are found on the tyre-derived aggregate's surface, which may contribute to inferior performance compared to conventional concrete. The study also suggests that reducing the water-binder ratio may improve the mechanical behavior of cement paste by reducing the number of nano-pores.
JOURNAL OF BUILDING ENGINEERING
(2023)
Article
Construction & Building Technology
Jianguo Han, Peiyu Yan
Summary: The study found that both WRA overdosage and vibration can decrease the segregation resistance of SCC, with vibration having a more significant impact. Bulk density distribution analysis and image analysis are effective ways to evaluate the segregation resistance of SCC. Segregation will decrease the permeability of SCC, while increasing the sand to paste volume ratio (STPVR) can improve the segregation resistance against WRA overdosage.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Green & Sustainable Science & Technology
Zhennan Su, Xianhai Li, Qin Zhang
Summary: The application of thermally activated coal gangue powder in cement can optimize the pore structure and microscopic morphology of concrete, and improve its flexural and compressive strengths. The active Al2O3 and SiO2 in coal gangue can react with the hydration product of cement, leading to the formation of calcium silicate hydrate gel, which fills and transforms the pores in the interfacial transition zone, and strengthens the bond between the matrix and aggregate.
JOURNAL OF CLEANER PRODUCTION
(2022)
Article
Materials Science, Composites
Wengui Li, Zhiyu Luo, Yixiang Gan, Kejin Wang, Surendra P. Shah
Summary: This paper investigates the mechanical properties of ITZ and geopolymer paste by using regular aggregates to prepare modelled geopolymer composites, revealing the differences between them under different silica modulus conditions. Nanoscratch technique is adopted for a quick scan of long distances, providing stable results with a given number of test data. Deconvolution analysis shows that abnormal properties of paste in geopolymer with a silica modulus of 1.0 could be related to defects.
COMPOSITES SCIENCE AND TECHNOLOGY
(2021)
Article
Construction & Building Technology
Suhui Zhang, Qiang Yuan, Qiuyi Li, Fei Zhang, Zonglin Xie
Summary: The microstructural characteristics of the bonding interfacial transition zone (ITZ) between magnesium ammonium phosphate cement (MPC) and ordinary Portland concrete (OPC) were investigated using BSE-EDS and microhardness methods. The ITZ was divided into two types: ITZ-P (MPC bonding to OPC paste) and ITZ-A (MPC bonding to aggregate). The microhardness analysis revealed that the peak interval of microhardness in ITZ-P (113.1 MPa) was higher than that in ITZ-A (87 MPa). The observation of denser hydration products and lower porosity in ITZ-P, as well as the enriched pore area in ITZ-A, supported these findings. Quantitative analysis showed that the denser hydration products accounted for 41.4% and the porosity was 4.3% in ITZ-P, compared to 29.3% and 12.5% in ITZ-A. The exposure of more aggregate hindered the attachment of the hydration products of MPC.
JOURNAL OF BUILDING ENGINEERING
(2023)
Article
Construction & Building Technology
Yingyao Tan, Takafumi Sugiyama, Katsufumi Hashimoto
Summary: This study conducted a natural diffusion test using a minute cylindrical specimen to determine the leaching of calcium ions in concrete. The effects of the interfacial transition zone (ITZ) were investigated by inserting limestone aggregate inside the specimens. The mass transfer changes were evaluated using synchrotron X-ray computed tomography, and the diffusion coefficients were obtained through simulation.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
Yan-Shuai Wang, Kai-Di Peng, Yazan Alrefaei, Jian-Guo Dai
Summary: This paper focuses on understanding the interfacial transition zone (ITZ) between geopolymer mortars and ordinary Portland cement concrete, analyzing failure modes of the bond interface and microscopic and chemical interactions between the materials. The occurrence of newly-formed gels and second hydration mechanisms at ITZs are also discussed.
CEMENT & CONCRETE COMPOSITES
(2021)
Article
Construction & Building Technology
Qi Jiang, Wei Liu, Shaopeng Wu, Xuanwen Gou
Summary: This study analyzes the erosion mechanisms of NaCl solution on asphalt concrete and finds that NaCl solution softens asphalt and promotes the intrusion of crystalline salt into it. Salt crystallization alters the surface roughness of aggregates, resulting in a decrease in skid resistance but an improvement in compressive strength. Additionally, the concentration of NaCl solution initially has no significant impact on the mechanical performance of asphalt concrete, but its domination gradually increases with the intensification of cyclic effects.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Lili Kan, Lan-qing Dai, Ning Kong, Bin Peng, Fei Wang
Summary: This paper investigates the effect of freezing and thawing cycles on the tensile behavior of cracked ultra-high performance concrete (UHPC). The results show that long-term freezing and thawing action deteriorates the cracking strength, tensile strength, tensile strain, and strain energy of cracked UHPC. On the other hand, the action of water generally favors the development of tensile properties of UHPC. The crack distribution tends to be unsaturated under freezing and thawing environment, and the re-hydration reaction is hindered. The pore structure near the crack varies under different environments.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Xin Xiao, Jingwei Li, Qingke Meng, Xiangshan Hou, Yanhui Liu, Xujiang Wang, Wenlong Wang, Shengtao Lu, Yuzhong Li, Yanpeng Mao, Tong Li
Summary: Preparing gypsum-based self-leveling mortar (GSLM) using beta-hemihydrate gypsum and solid wastes-derived sulfoaluminate cement (WSAC) can improve the mechanical performance of the mortar, but phosphorus impurities can weaken the hydration speed and degree.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Sihang Bao, Junzhen Di, Yanrong Dong, Ziqing Gao, Qing Gu, Yuanfang Zhao, Hongyu Zhai
Summary: Tailings dam break and leakage accidents pose a threat to the safety of people in mining areas and cause severe environmental pollution. This study focuses on solidifying tailing sand using microbial induced calcite precipitation (MICP) to improve strength and fix heavy metals. The curing time of MICP bio-cemented tailings is found to significantly impact the strength of tailings, while its effect on heavy metal fixation is minimal. The optimized MICP curing time is 10 days, resulting in improved strength and cementation of tailings particles.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Ferhat Benmahiddine, Fares Bennai, Achraf Charaka, Ameur El Amine Hamami, Abdelkader Tahakourt, Rafik Belarbi
Summary: This paper studied the effects of hysteresis on the hygrothermal behavior at the building scale. Through laboratory validation and numerical simulations, it was found that hysteresis has a significant impact on the relative humidity and total heat fluxes in buildings, while it does not have a noticeable effect on temperature variations.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
You Gao, Wei He, Xiayang Zhang, De'an Sun, Pei Li
Summary: This study determined the boundary line between the swelling and compression deformation zone in lateritic clay through wetting tests, and proposed a simple bimodal SWRC model. It also found that the existing strength model underestimated the tested values in the medium to high suction range, therefore a segmented strength equation was introduced for enhanced predictions of the strength properties of lateritic clay.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Prabhath Ranjan Kumar Soda, Asheer Mogal, Kalyan Chakravarthy, Nikhil Thota, Nimish Bandaru, Sanjay Kumar Shukla, K. M. Mini
Summary: This study investigates the use of encapsulated bacteria to improve the self-healing ability of concrete. Through various tests, it is found that using 20% cement-coated alginate beads (CCAB) and 5% nanosilica (NS) can achieve optimal strength and healing. This research is significant for enhancing the durability of concrete.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Shizhe Wang, Haiping Wu, Wen Yang, Wei Wang, Zhibo Zhu, Kun Nie, Luoxin Wang, Hua Wang, Jing Wu
Summary: In this study, photothermal-heat storage concrete (PHSC) was developed with excellent photothermal conversion performance and heat storage capacity. By absorbing and storing solar energy during the day and releasing it at night, PHSC can effectively reduce energy consumption in buildings.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Robin Deb, Jialuo He, Geetika Mishra, Yaghoob (Amir) Farnam
Summary: Incorporation techniques of phase change materials in cementitious composites have a significant influence on thermal properties. This study investigated the thermal behavior of low-temperature PCM when subjected to varying temperature change rates and pore confinement inside the porous network of lightweight aggregates. The results showed that ramp rates affect the nucleation and crystallization growth process during the phase transition, and the pore structure of the aggregates affects the supercooling phenomenon and confinement pressure of the PCM.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Eduardo Ferreira, Payam Sotoudeh, Dagmar Svecova
Summary: This study investigates the fatigue behavior of concrete under different stress reversal conditions. The results indicate that stress reversal generally causes more severe damage and reduces the cycles to failure compared to tensile fatigue. Additionally, adding some level of compression contributes to the energy required for failure under stress reversal fatigue. Specimens with higher concentration of fractured aggregates achieve longer fatigue lives.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Mag Raj Gehlot, Sandeep Shrivastava
Summary: This study evaluates the compatibility relationship between plaster bonds and the substrate under an accelerated aging environment, and finds that incorporating an appropriate amount of granite cutting waste can improve the strength parameters and adhesion of the cement mortar.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Min Zhang, Qirui Luo, Mingke Deng, Shixing Zhao
Summary: This study investigated the bond behavior between carbon FRCM composites with added short fibers and concrete substrates. The effects of different factors were considered and 36 specimens were tested and discussed. The experimental results were analyzed in terms of failure mode, load-slip curve, and characteristic parameters, and the contribution of weft yarns was taken into account in the developed bondslip model.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Dengkai Liu, Hongniao Chen, Ray Kai Leung Su
Summary: The susceptibility of building stones to fire and high temperature was investigated in this study by examining their physical and mechanical properties. The results show that both compressive and tensile properties of stones are affected by temperature changes. The tensile strength is particularly sensitive to temperature changes, requiring special attention to the components subjected to tensile stress in stone buildings. Principal component analysis was used to predict the mechanical properties of stones, providing a new method for calculating the residual mechanical properties after high temperature or fire.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Joso Maria Raposo, Eduardo Cavaco, Luis Costa Neves, Eduardo Julio
Summary: This paper investigates the correlation between the friction coefficient and the surface roughness of concrete-to-concrete interfaces. Experimental tests were performed on specimens with different surface treatments, and the surface roughness parameters were analyzed and correlated with the shear strength and friction coefficient. The results showed that certain roughness parameters had a strong positive correlation with the friction coefficient, while others had little or no correlation. A novel combined roughness parameter with optimized correlation was proposed.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Construction & Building Technology
Chiara Riccardi, Massimo Losa
Summary: The interest in using bio materials in asphalt pavements is growing due to economic reasons and environmental benefits. This study aimed to review the use of bio extenders as additives in binders, with a focus on replacements greater than 20% of fossil binder. The properties of bio-extended binders were found to vary substantially depending on the biomass source and production process.
CONSTRUCTION AND BUILDING MATERIALS
(2024)