Zhang Yunlong, Wang Jianxin, Wang Jing, Qian Xuesong
School of Transportation Science and Engineering, Jilin Jianzhu University, Xincheng Street, Changchun, 130118, Jilin, China.
Research Center of Traffic Disaster Prevention and Mitigation Jilin Jianzhu University, Jilin Jianzhu University, Xincheng Street, Changchun, 130118, Jilin, China.
Sci Rep. 2022 May 12;12(1):7787. doi: 10.1038/s41598-022-11836-y.
The emergence of shotcrete provides a new idea for construction methods, but with the development of society, the traditional shotcrete has been unable to meet the needs of structure. Therefore, concrete with better material properties is needed to replace traditional shotcrete. Reactive powder concrete (RPC) is a well-known ultrahigh strength concrete and widely used. Its material properties are better than shotcrete. However, the sprayable performance of RPC and the properties of this sprayed materials have not been reported. Therefore, to make up for the deficiency of ordinary shotcrete, the material properties of sprayed RPC were studied in depth. Response surface method was used to study the effects of different silica fume content, fly ash content and steel fiber volume content on workability, mechanical properties and crack sensitivity. The sprayed reactive powder concrete (sprayed RPC) was proposed for the first time. All models were reliable through variance analysis. The performance of sprayed RPC was better when the workability was between 140 and 160 mm. When the silica fume/binder ratio was 15%, the fly ash/binder ratio was 13.203%, and the volume content of steel fibers was 2%, the mechanical properties and crack sensitivity of sprayed RPC can reach a satisfactory degree. By studying the workability, mechanical properties and crack sensitivity of sprayed RPC, the optimum mix ratio of sprayed RPC was obtained. Steel fiber sprayed RPC can detect structural damage. Results lay the foundation for popularization and application to practical engineering.
喷射混凝土的出现为施工方法提供了新思路，但随着社会的发展，传统喷射混凝土已无法满足结构需求。因此，需要性能更优的混凝土来取代传统喷射混凝土。活性粉末混凝土（RPC）是一种著名的超高强混凝土且应用广泛，其材料性能优于喷射混凝土。然而，RPC的可喷射性能以及这种喷射材料的性能尚未见报道。因此，为弥补普通喷射混凝土的不足，对喷射RPC的材料性能进行了深入研究。采用响应面法研究了不同硅灰含量、粉煤灰含量和钢纤维体积含量对工作性能、力学性能和裂缝敏感性的影响。首次提出了喷射活性粉末混凝土（喷射RPC）。通过方差分析表明所有模型可靠。当工作性能在140至160毫米之间时，喷射RPC的性能更佳。当硅灰/胶凝材料比为15%、粉煤灰/胶凝材料比为13.203%且钢纤维体积含量为2%时，喷射RPC的力学性能和裂缝敏感性可达到满意程度。通过研究喷射RPC的工作性能、力学性能和裂缝敏感性，得到了喷射RPC的最佳配合比。钢纤维喷射RPC可用于检测结构损伤。研究结果为其在实际工程中的推广应用奠定了基础。
