文献类型：期刊文献

英文题名：Strength performance and microscopic mechanism of cement mortar incorporating fine recycled concrete aggregate and natural sand

作者：Wu, Erlu[1,2];Ma, Xukun[1];Fang, Chulei[1,3];Li, Na[1];Jia, Liang[4];Jiang, Ping[1];Wang, Wei[1]

机构：[1]Shaoxing Univ, Shaoxing Key Lab Interact Soft Soil Fdn & Bldg Str, Sch Civil Engn, Shaoxing 312000, Peoples R China;[2]Chongqing Jiaotong Univ, Sch Civil Engn, 66 Xuefudadao Rd, Chongqing 400074, Peoples R China;[3]Jiangsu Liyang Secondary Vocat Sch, Sch Construct Engn, Changzhou 213300, Peoples R China;[4]Lanzhou Univ Technol, Sch Civil Engn, Lanzhou 730050, Gansu, Peoples R China

年份：2025

卷号：100

外文期刊名：JOURNAL OF BUILDING ENGINEERING

收录：SCI-EXPANDED(收录号：WOS:001414484100001)、、EI(收录号：20250217654546)、Scopus(收录号：2-s2.0-85214306903)、WOS

语种：英文

外文关键词：Recycled aggregate mortar; Waste concrete; Compressive strength; Flexural strength; Microstructure

外文摘要：The resource utilization of waste concrete offers significant environmental and economic benefits by mitigating the environmental issues associated with its disposal and reducing the consumption of natural resources. However, waste concrete aggregates with a particle size greater than 4.75 mm will reduce the mechanical strength of recycled aggregate concrete (RAC). In this study, waste concrete was crushed into aggregates with a particle size of less than 4.75 mm to replace natural sand at varying substitution rates (0 %, 20 %, 30 %, 40 %, 50 %, 60 %, 80 % and 100 %). The impact of these substitution rates on the strength characteristics of recycled aggregate mortar (RAM) was thoroughly examined. The experimental results indicate that the substitution rate of recycled concrete aggregate (RCA) significantly influences the compressive and flexural strengths of RAM, with the optimum strength observed at a substitution rate of 40 %. At 28 days, the compressive strength reached 5.8 MPa and the flexural strength was 2.6 MPa, representing a 10 % and 21 % increase, respectively, compared to the control group. Additionally, the compressive strength of all RAM mixtures with varying RCA substitution rates met the strength requirement for M5 mortar at 28 days. Microscopic analyses revealed that the incorporation of RCA led to changes in the mineral composition, particularly an increase in SiO2, CaCO3 and Ca(OH)2 content. Furthermore, the presence of RCA enhanced the hydration of cement, resulting in the formation of additional CaCO3 and CSH gel. This study provides a theoretical foundation for the use of waste concrete in RAM, demonstrating its potential for improving mortar strength, reducing environmental impacts, and conserving resources. The findings not only contribute to the body of knowledge on waste concrete resource utilization but also offer valuable insights for future research in related fields.