北京建筑大学学报2026，Vol.42Issue(4)：135-142,8.DOI:10.19740/j.2096-9872.2026.04.14
再生砂对喷射混凝土力学性能的影响及微观分析研究
A Study on the Effect of Recycled Sand on the Mechanical Properties of Shotcrete and Its Microstructural Analysis
摘要
Abstract
With the acceleration of urbanization and the resulting shortage of natural sand and gravel resources,the recycling of construction waste has become a key direction for the development of green building materials.This paper aims to investigate the effect of recycled sand substitution rates(0,35％,70％,and 100％)on the mechanical properties of shotcrete.Combined microstructural analysis with microhardness testing.The study reveals the microscopic mechanisms by which the water absorption of recycled sand affects concrete performance.The results show that as the replacement rate of recycled sand increases,The slump and slump flow of freshly mixed shotcrete decreased,reaching minimum values of 185 mm and 425 mm respectively,while the 1-day compressive strength of the shotcrete increases,reaching a maximum of 17.8 MPa;both the 28-day compressive strength and split tensile strength exhibited a trend of initially increasing and then decreasing,peaking at a 70％replacement rate;the incorporation of recycled sand enhanced the bond strength between the concrete and the substrate,reaching a maximum of 1.46 MPa at 28 days.Microstructural analysis indicates that the high water absorption of the old mortar on the surface of the recycled sand played a role in water-induced densification during the early stages,effectively reducing the local water-to-binder ratio in the interfacial transition zone and improving the density of the interface transition zone.In the later stages,however,the numerous microcracks in the recycled sand itself weakened its load-bearing capacity as a spatial skeleton,resulting in a decline in mechanical properties.关键词
再生砂喷射混凝土/喷射混凝土/再生砂/再生砂替代率/力学性能Key words
recycled sand shotcrete/shotcrete/recycled sand/recycled sand replacement ratio/mechanical properties分类
建筑与水利引用本文复制引用
赵瀚第,邓松文,周文娟,张志伟,周明丽..再生砂对喷射混凝土力学性能的影响及微观分析研究[J].北京建筑大学学报,2026,42(4):135-142,8.基金项目
科技部国家重点研发计划项目(2022YFC3803403). （2022YFC3803403）
