Guiwu Lin, Kaige Liu, Yuliang Chen^*, Yunpeng Ji, Rui Jiang

Journal of Renewable Materials, Vol.11, No.11, pp. 3957-3975, 2023, DOI:10.32604/jrm.2023.028290

Abstract This paper presents an experimental study to explore the compressive properties of fiber recycled aggregate concrete. A total of 75 specimens with the replacement rate of recycled coarse aggregate and fiber type were conducted under a uniaxial compressive test. The failure modes, stress-strain whole curves, peak stress, peak strain, and energy dissipation capacity were systematically observed and revealed. Test results indicate that steel fiber has the best modification effect on energy dissipation capacity and the toughness index of recycled concrete, corresponding to the enhancement of 81.75% and 22.90% on average. The addition of polyvinyl alcohol fiber can effectively improve the… More > Graphic Abstract

Xintong Chen, Pinghua Zhu^*, Xiancui Yan, Lei Yang, Huayu Wang

Journal of Renewable Materials, Vol.11, No.6, pp. 2953-2967, 2023, DOI:10.32604/jrm.2023.027140

Abstract With the emphasis on environmental issues, the recycling of waste concrete, even recycled concrete, has become a hot spot in the field of architecture. But the repeated recycling of waste concrete used in harsh environments is still a complex problem. This paper discusses the durability and recyclability of recycled aggregate concrete (RAC) as a prefabricated material in the harsh environment, the effect of high-temperature curing (60°C, 80°C, and 100°C) on the frost resistance of RAC and physical properties of the second generation recycled coarse aggregate (RCA₂) of RAC after 300 freeze-thaw cycles were studied. The frost resistance of RAC was… More >

Peng Zhang^1,2, Wenshuai Wang¹, Yuanxun Zheng^1,*, Shaowei Hu^2,3

Journal of Renewable Materials, Vol.11, No.4, pp. 1853-1879, 2023, DOI:10.32604/jrm.2023.024981

Abstract Using recycled aggregate (RA) and slag instead of natural aggregate (NA) and cement can reduce greenhouse gas emissions (GHGE) and achieve effective waste recovery. In recent years, RA has been widely used to replace NA in concrete. Every year, several researchers conduct investigations on the mechanical performance and durability of recycled aggregate concrete (RAC). Due to the loose and porous material properties of RA, the mechanical properties and durability of RAC, such as strength, carbonation resistance, permeability resistance and chloride ion penetration resistance, are greatly reduced compared with natural aggregate concrete. In contrast, concrete containing slag instead of NA and… More >

Zhijie Fan¹, Huaxin Liu¹, Genjin Liu^2,*, Xuezhi Wang¹, Wenqi Cui¹

Journal of Renewable Materials, Vol.11, No.4, pp. 1763-1791, 2023, DOI:10.32604/jrm.2023.024319

Abstract The development of recycled aggregate concrete (RAC) provides a new approach to limiting the waste of natural resources. In the present study, the mechanical properties and deformability of RACs were improved by adding basalt fibers (BFs) and using external restraints, such as a fiber-reinforced polymer (FRP) jacket or a PVC pipe. Samples were tested under axial compression. The results showed that RAC (50% replacement of aggregate) containing 0.2% BFs had the best mechanical properties. Using either BFs or PVC reinforcement had a slight effect on the loadbearing capacity and mode of failure. With different levels of BFs, the compressive strengths… More > Graphic Abstract

Mohammad Akhtar¹, Abdulsamee Halahla², Amin Almasri^3,*

Structural Durability & Health Monitoring, Vol.15, No.4, pp. 335-348, 2021, DOI:10.32604/sdhm.2021.015988

Abstract This research aims to study the effect of elevated temperature on the compressive strength evolution of concrete made with recycled aggregate. Demolished building concrete samples were collected from four different sites in Saudi Arabia, namely from Tabuk, Madina, Yanbu, and Riyadh. These concretes were crushed and recycled into aggregates to be used to make new concrete samples. These samples were tested for axial compressive strength at ages 3, 7, 14, and 28 days at ambient temperature. Samples of the same concrete mixes were subjected to the elevated temperature of 300°C and tested for compressive strength again. The experimental result reveals… More >

Tan Li, Jianzhuang Xiao^*, Amardeep Singh

Journal of Renewable Materials, Vol.10, No.3, pp. 699-720, 2022, DOI:10.32604/jrm.2022.016898

Abstract To model the concrete with complex internal structure of concrete with large sized aggregates the effect of internal structure on uniaxial compression behavior are studied. Large-sized recycled aggregates behave differently in the concrete matrix. To understand the influence on concrete matrix, a finite element model was developed to model recycled aggregate concrete composed of multiple randomly distributed irregular aggregates and cement mortar. The model was used to calculate the effect of large-size recycled coarse aggregate (LRCA) on the strength of recycled aggregate concrete and simulate the compressive strength of cubes and prisms. The factors such as the strength of new… More >

Chunyang Liu^1,2,*, Jia Xu¹, Yifan Gu¹, Ruofan Shi¹

FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.6, pp. 1129-1142, 2021, DOI:10.32604/fdmp.2021.017376

Abstract In order to study the axial compression performances of short columns made of recycled aggregate concrete, four samples were designed with different recycled aggregate replacement rates and carbon fibre reinforced plastics (CFRP) sheets. Then, monotonic loading was implemented to assess the variation trends of their axial compression properties. The ABAQUS finite element software was also used to determined the compression performances. Good agreement between experimental and numerical results has been found for the different parameters being considered. As shown by the results, recycled coarse aggregates result in improved ductility and better deformation performance of the specimens. The failure of specimens… 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 >

Boheng Zhu¹, Huaxin Liu^1,*, Genjin Liu², Abasal Hussain², Xiaofei Zhang³, Xuezhi Wang¹

Journal of Renewable Materials, Vol.9, No.3, pp. 507-521, 2021, DOI:10.32604/jrm.2021.013580

Abstract The aim of this study is to improve the bond performance of basalt fiber reinforced polymer (BFRP) bars and recycled aggregate concrete (RAC) after being exposed to high temperatures. The bond behavior (failure modes, bond strength, bond stress-slip curves) between BFRP bars and hybrid fiber recycled aggregate concrete (HFRAC) after being exposed to temperatures ranging from 20°C up to 500°C was studied by using pull-out tests. The effect of high temperatures on mechanical properties of concrete (compressive strength, splitting tensile strength) and tensile strength of BFRP bars was also investigated. The bond strength decreased as the temperature increased and the… More >

Zhenhua Duan, Nv Han, Amardeep Singh, Jianzhuang Xiao^*

Journal of Renewable Materials, Vol.8, No.11, pp. 1375-1390, 2020, DOI:10.32604/jrm.2020.013044

Abstract Recycled aggregates (RA) are frequently obtained from various unknown sources, which caused variation in properties among recycled aggre- gates concrete (RAC). This paper investigated the macro and microscopic proper- ties of RAC prepared with RAs originated from different parent concretes with 90-day strength ranging from 30 MPa to 100 MPa. These parent concretes were prepared in advance and crushed to produce RA of distinct qualities. The attached mortar content can reach up to 69% in the concrete with highest strength grade. The microscopic investigation on different RAC was conducted with the X-ray Micro-Computed Tomography scanning technique and image process. Experi-… More >