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
Jian Liu, Kunlin Ma, Jingtao Shen, Youjun Xie, Guangcheng Long
Summary: Carbonation is an important method to enhance recycled aggregate. The strengthening effect of carbonation on interfacial transition zones (ITZs) in recycled concrete (RC) was investigated. The microhardness, width, and micromorphology of three types of ITZs were analyzed. The results showed that carbonation had different effects on the ITZs. Carbonation did not effectively strengthen ITZ1, but significantly enhanced ITZ2 and ITZ3. Soaking recycled aggregate in CH saturated solution pretreatment further improved the enhancement effect.
JOURNAL OF BUILDING ENGINEERING
(2023)
Article
Construction & Building Technology
Song Gao, Jia Guo, Yaguang Zhu, Zuquan Jin
Summary: Applying recycled aggregate aligns with green and environmental protection concept, but it also brings a complex interface structure that deteriorates the performance of recycled aggregate concrete. By investigating the properties of the interfacial transition zones (ITZs) and using digital image correlation (DIC) technology, the study analyzed the influence on the performance of recycled aggregate concrete. The experimental results showed that targeted strengthening of ITZs improved the mechanical properties and reduced porosity, with mortar strengthening being more effective.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
Jing Hu, Pengfei Liu, Qibo Huang, Zhendong Qian, Sang Luo
Summary: Studying the effect of recycled aggregates (RA) on the interfacial zone failure of asphalt mixture can enhance the utilization of construction and demolition wastes (CDW) in pavement engineering. Results show that increasing RA percentage causes more interface failure, with the damage of cement mortar and its interface with asphalt mortar being the primary resources of failure.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Construction & Building Technology
Jian Liu, Kunlin Ma, Jingtao Shen, Jianbin Zhu, Guangcheng Long, Youjun Xie, Baoju Liu
Summary: This study investigated the influence of carbonation and chemical enhancement on the microstructure of recycled concrete aggregate (RCA). The results showed that carbonation had limited strengthening effect on the interfacial transition zone (ITZ) between old aggregate and new paste (ITZ1), while soaking RCA in Na2SiO3 saturated solution and CEM-SF slurries improved ITZ1. Both carbonation and chemical enhancement had obvious improvement on ITZ2. Soaking in CEM-SF slurries had a better improvement effect on ITZs.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
Qibo Huang, Zhendong Qian, Jing Hu, Dong Zheng, Leilei Chen, Meng Zhang, Jinzhu Yu
Summary: This study investigated the interfacial transition zones (ITZs) in recycled concrete aggregate asphalt mixture (RCAM) using nanoindentation test, backscattered electron image-analysis (BSE), and energy dispersive spectroscopy (EDS). The results showed that the thickness and elastic modulus of ITZs in RCAM varied with different components in recycled concrete aggregate (RCA), and the elastic modulus increase could indicate reduced asphalt exfoliation degree. Additionally, the study highlighted the potential effects of aggregate compositions and morphologies on ITZ and adhesion between RCA and asphalt.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Construction & Building Technology
Kai Wu, Yuan Hu, Lintao Zhang, Yufeng Su, Jianguo Han, Zhenghong Yang, Geert De Schutter
Summary: This study found that utilizing steel slag and recycled concrete as fine aggregate has a significant impact on the compressive strength and chloride migration coefficient of concrete, with steel slag aggregate concrete showing better performance. The research results indicate that the use of supplementary cementitious materials in natural aggregate concrete can improve chloride resistance ability.
STRUCTURAL CONCRETE
(2021)
Article
Construction & Building Technology
Hongru Zhang, Xin Xu, Shangliang Su, Weilai Zeng
Summary: The study aimed to improve the performance of recycled aggregate concrete (RAC) against internal steel corrosion by treating the recycled aggregate (RA) with different methods, showing that using a sulfoaluminate cement treatment resulted in more significant enhancement in resistance to steel corrosion compared to using a water glass solution.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Construction & Building Technology
Hancheng Dan, Mengjin Li, Jiawei Tan, Hanbo Dan, Zhiming Ma, Shenglong Ma
Summary: Geopolymer technology is advantageous in stabilizing recycled asphalt pavement (RAP) for road construction materials. This study combines molecular dynamics simulations and experimental characterization to investigate the properties of the interfacial transition zone (ITZ) in geopolymer-stabilized RAP. The findings suggest that aging asphalt molecules on the RAP surface have an affinity for Na+ present in geopolymers, leading to interfacial interactions. The simulation results were verified by SEM-EDS analysis, indicating the growth of C(N)-A-S-H at the interface and strong affinity and external chemical bonding.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
Hongru Zhang, Bingjian He, Baojun Zhao, Paulo J. M. Monteiro
Summary: This study investigates the use of diatomite to enhance the performance of recycled aggregate concrete (RAC). The addition of calcined diatomite as a partial replacement of ordinary Portland cement (OPC) in the RAC mixture significantly improves its strength and impermeability. The nucleation effects and high pozzolanic reactivity of diatomite contribute to the more complete hydration of cement in RAC, while reducing the proportion of large capillary pores and decreasing the average porosity of the new interfacial transition zone (ITZ).
CONSTRUCTION AND BUILDING MATERIALS
(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
Chemistry, Physical
Chengyan Hou, Haibo Zhang
Summary: This study investigates the impact of silane coupling agents on the surface properties of aggregates and the performance of mortar. The results show that different types of silane have a significant effect on the surface properties of aggregates, and the improvement in mortar performance varies with different silane-modified aggregates.
Article
Construction & Building Technology
Hanbing Zhao, Wengui Li, Yixiang Gan, Kejin Wang, Zhiyu Luo
Summary: This study investigates the microtopography and bonding behaviours of interfacial transition zones (ITZs) using modelled recycled aggregate concrete (MRAC). It shows that waste glass powder (WGP) can improve concrete properties by reacting with the old mortar to reduce porosity and cracks, and generating calcium silicate hydrate (C-S-H) gel.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
Surong Luo, Qian Lin, Tengwei Lin, Dehui Wang, Shijie Wang
Summary: Presoaking recycled coarse aggregate in calcium hydroxide and increasing carbonation pressure can improve the carbonation effectiveness. The optimal carbonation condition is a pressure of 4 bar and a concentration of calcium hydroxide solution of 0.04 mol/kg. Pressurized carbonation with presoaking in calcium hydroxide solution enhances the toughness and crack propagation process of recycled coarse aggregate concrete, while simple pressurized carbonation deteriorates the toughness.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
Xianfeng Wang, Guanhong Du, Lianmin Cai, Jun Ren, Weilun Wang
Summary: This study evaluates the performance of crystallizer treatment on recycled concrete aggregate (RCA) and the durability and permeability of corresponding recycled aggregate concrete (RAC). The results show that crystallizer treatment significantly improves the chloride diffusion resistance of RAC and improves its permeability by compacting the microstructure and reducing the pore size.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
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)