Yadong Bian¹, Xuan Qiu¹, Jihui Zhao^2,*, Zhong Li², Jiana Ouyang²

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.1, pp. 45-58, 2024, DOI:10.32604/fdmp.2023.029299

Abstract In this paper, the durability of cement mortar prepared with a recycled-concrete fine powder (RFP) was examined; including the analysis of a variety of aspects, such as the carbonization, sulfate attack and chloride ion erosion resistance. The results indicate that the influence of RFP on these three aspects is different. The carbonization depth after 30 days and the chloride diffusion coefficient of mortar containing 10% RFP decreased by 13.3% and 28.19%. With a further increase in the RFP content, interconnected pores formed between the RFP particles, leading to an acceleration of the penetration rate of CO₂ and Cl⁻ . When… More > Graphic Abstract

Zhenqing Shi¹, Guomin Sun¹, Jianyong Pang^2,*

Structural Durability & Health Monitoring, Vol.17, No.3, pp. 239-255, 2023, DOI:10.32604/sdhm.2023.022816

Abstract Applying recycled concrete for engineered projects not only protects the ecological environment but also improves the utilization rate of waste concrete to satisfy sustainable development requirements. However, the mechanical properties of recycled concrete are not as good as those of ordinary concrete. To enhance the former’s performance and increase its popularity and application in engineering fields, notable advances have been made by using steel, synthetic, plant, and mineral fiber materials. These materials are added to recycled concrete to improve its mechanical properties. Studies have shown that (1) steel fibers have a distinct reinforcing effect and improve the strength, toughness, and… More >

Xiaoyan Liu^1,*, Li Liu¹, Junqing Zuo², Pingzhong Zhao¹, Xian Xie¹, Shijie Li¹, Kai Lyu^3,*, Chunying Wu⁴, Surendra P. Shah⁵

Journal of Renewable Materials, Vol.10, No.10, pp. 2685-2698, 2022, DOI:10.32604/jrm.2022.019527

Abstract Due to the existence of the attached mortar, the performance of the recycled concrete aggregate (RCA) is inferior to the natural aggregate, which significantly limits its wide application in industry. In this study, five kinds of modified solutions were used to modify the surface of RCA, and the modification effects were compared. The results showed that sodium silicate, nano-silica (NS), Bacillus pasteurii and soybean powder had relatively good modification effects on RCA, which could reduce the crushing value and water absorption, and increase apparent density. The composite solution (15% sodium silicate and 2% NS) and soybean powder solution had better… More >

Chao Liu^1,2,*, Huawei Liu^2,*, Jian Wu¹

Journal of Renewable Materials, Vol.10, No.5, pp. 1397-1414, 2022, DOI:10.32604/jrm.2022.018386

Abstract In this paper, recycled bricks and recycled concrete were applied to prepare eco-friendly recycled mixed powder (RMP) cementitious material, as a supplementary to replace conventional cement for improve the recycling of construction and demolition waste. Based on the effect of cementitious materials on the hydration of silicate cement, the effects of RMP on the workability, mechanical properties and microstructure of recycled mixed powder concrete (RMPC) with the different replacement ratios and the 8:4 and 6:4 mixing ratio of recycled brick powder (RBP) and recycled concrete powder (RCP) were investigated. The results showed that the fluidity of the mix decreased with… More >

Chunyang Liu^1,2,*, Yangyang Wu¹, Yingqi Gao¹, Zhenyun Tang³

FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.5, pp. 947-958, 2021, DOI:10.32604/fdmp.2021.016283

Abstract In order to study the performances of high-strength concrete beams including steel fibers and large-particle recycled aggregates, four different beams have been designed, tested experimentally and simulated numerically. As varying parameters, the replacement rates of recycled coarse aggregates and CFRP (carbon fiber reinforced polymer) sheets have been considered. The failure mode of these beams, related load deflection curves, stirrup strain and shear capacity have been determined through monotonic loading tests. The simulations have been conducted using the ABAQUS finite element software. The results show that the shear failure mode of recycled concrete beams is similar to that of ordinary concrete… More >

Xi Chen^1,2, Ying Li^1,2,*, Hualei Bai^1,2, Liyuan Ma^1,2

Journal of Renewable Materials, Vol.9, No.12, pp. 2189-2208, 2021, DOI:10.32604/jrm.2021.015394

Abstract Recycled concrete powder (RCP) is used more and more in cement-based materials, but its influence on the hydration process is still unclear. Therefore, this paper studied the influence of recycled concrete powder (RCP) on the hydration process of cement and provides a theoretical basis for the hydration mechanism of cement composite materials. The hydration heat method was used to systematically analyze the thermal evolution process of cement paste with or without RCP. Hydration products were identified using X-ray diffraction (XRD) and thermal analysis (TG–DSC). The pore structure change of cement pastes was analyzed by mercury intrusion porosimetry (MIP) method. The… More > Graphic Abstract

Tao Li^1,2,*, Sheliang Wang², Fan Xu^2,*, Binbin Li³, Bin Dang¹, Meng Zhan⁴, Zhiqi Wang⁵

Journal of Renewable Materials, Vol.9, No.8, pp. 1413-1432, 2021, DOI:10.32604/jrm.2021.012744

Abstract To improve the resource utilization of recycled aggregate concrete (RAC) and make use of the unique pozzolanic activation characteristics of iron ore tailing (IOT), the constitutive curves of tailing recycled concrete (TRC) before and after carbonization were analyzed theoretically, experimentally and microscopically. Firstly, according to the experimental data, the damage constitutive and related damage parameters of TRC were theoretically established by Weibull probability distribution function. Secondly, the comprehensive damage parameter b under different working conditions was studied. Finally, the damage mechanism was formed by EDS and SEM. The results showed that the damage constitutive model based on Weibull probability distribution… More >

Qiong Liu, Jianzhuang Xiao^*, Amardeep Singh

Journal of Renewable Materials, Vol.9, No.7, pp. 1309-1327, 2021, DOI:10.32604/jrm.2021.015326

Abstract The failure characteristics of recycled concrete containing brick aggregates are still indistinct, especially how the angular aggregates effect the crack propagation. Based on the concept of modeled concrete, the development of cracks in concrete containing the natural aggregate and brick aggregate under a compression loading was studied. The strain distribution was analyzed with the Digital Image Correlation (DIC). The modeled aggregates include circular and squared ones, and the squared modeled aggregates were placed in different orientations, including 0°, 22.5° and 45°. The results show that when the aggregate is placed at 45°, the upper and lower vertices of the aggregate… More >

Xinzhan Chen¹, Xiangqing Kong^1,2,*, Ying Fu^2,*, Wanting Sun¹, Renguo Guan²

Journal of Renewable Materials, Vol.9, No.6, pp. 1169-1188, 2021, DOI:10.32604/jrm.2021.014809

Abstract This paper experimentally investigated the flexural behavior of reinforced recycled aggregate concrete (RAC) beams reinforced with glass fiber-reinforced polymer (GFRP) bars. A total of twelve beams were built and tested up to failure under four-point bending. The main parameters were reinforcement ratio (0.38%, 0.60%, and 1.17%), recycled aggregate replacement ratio (R = 0, 50%, and 100%) and longitudinal reinforcement types (GFRP and steel). The flexural capacity, failure modes, flexibility deformation, reinforcement strains and crack distribution of the tested beams were investigated and compared with the calculation models of American code ACI 440.1-R-15, Canadian code CSA S806-12 and ISIS-M03-07. The tested… More >

Wojciech Kubissa¹, Roman Jaskulski¹, Pavel Reiterman^2*

Journal of Renewable Materials, Vol.5, Suppl.1, pp. 53-61, 2017, DOI:10.7569/JRM.2017.634103

Abstract This article deals with an experimental study concerning the development of concrete mixtures with significant ecological benefits. The studied concrete mixtures were based on blast-furnace cement, with an additional application of supplementary cementitious materials—fly ash, metakaolin, and silica fume and fluidized fly ash. Coarse aggregate in the form of crushed concrete was applied for all studied concrete mixtures. The experimental program was primarily focused on the assessment of the durability properties of the studied mixtures in terms of mechanical tests, absorption tests, chloride migration coefficient tests, water penetration tests, and accelerated carbonation depth tests. The results obtained showed good potential… More >