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 >

Fan Li^1,#, Xin Cai^2,#, Yanan Zhang^1,*, Xingwen Guo^2,*, Minmin Jiang³

Journal of Renewable Materials, Vol.11, No.4, pp. 1745-1762, 2023, DOI:10.32604/jrm.2022.024380

Abstract In this paper, the effects of different influencing factors and factor interaction on the compressive strength and permeability of recycled aggregate pervious concrete (RAPC) were studied based on the response surface method (RSM). By selecting the maximum aggregate size, water cement ratio and target porosity as design variables, combined with laboratory tests and numerical analysis, the influences of three factors on the compressive strength and permeability coefficient of RAPC were revealed. The regression equation of compressive strength and permeability coefficient of recycled aggregate pervious concrete were established based on RSM, and the response surface model was optimized to determine the… 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 >

Shoukai Chen^1,4,5, Chunpeng Xing¹, Mengdie Zhao^2,*, Junfeng Zhang³, Lunyan Wang^1,4,5,*, Qidong He⁶

Journal of Renewable Materials, Vol.10, No.3, pp. 799-819, 2022, DOI:10.32604/jrm.2022.017285

Abstract

Pervious concrete is recommended, which is of great benefit to the ecological environment and human living environment. In this paper, the influences of five water-cement ratios and four fly ash contents to replace the cement by mass with a water-cement ratio of 0.30 on the properties of Recycled Aggregate Pervious Concrete (RAPC) were studied. Following this, based on the Grey relational-Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) optimization method, the strength, permeability, abrasion loss rate, and material costs of RAPC were adopted as evaluation indices to establish a mix proportion optimization model. The results show that… 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 >

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 >