再生砖混材料力学和耐久特性及其在机场道面垫层的应用

Mechanical and Durability Characteristics of Recycled Brick-Concrete Materials and Their Application in Airport Pavement Cushion

摘要:

利用回收砖混材料设计了骨架密实型再生砖混混合料（RBCM）；结合多种试验综合表征了RBCM在抗压、抗拉、贯入受力状态下的力学特征；考虑实际工况设计了试件循环和粒料循环两类耐久环境，并通过无侧限抗压强度试验量化了RBCM的耐久性能演变；依据现场试验段验证RBCM垫层的工程应用性能。结果表明，RBCM垫层的渗透性较差，宜在其上部设置透水垫层；水泥用量增加对RBCM抗压能力和破坏形态改善明显，其抗压和贯入强度较高，抗拉能力较差；少量水泥掺入使RBCM经过30次循环后的耐久系数仍大于50%；即使不掺水泥，再生砖混垫层的密实度和力学性能仍满足现行垫层设计指标的要求。

Abstract:

This paper designed a skeleton dense recycled brick-concrete materials（RBCM） using recycled brick-concrete materials. The mechanical characteristics of RBCM under compressive， tensile， and penetration stresses were synthesized by various tests. Considering the actual working conditions， two types of durability environments， i.e.， the specimen cycle and the particle cycle， were designed， and the durability evolution of RBCM was quantified by an unconfined compressive strength test. The engineering application performance of the RBCM cushion was verified based on the field test section. The results show that the permeability of the RBCM cushion is poor， and it is appropriate to pave a permeable cushion on the upper part of RBCM cushion. The increase in cement content significantly improves the compressive strength and failure mode of RBCM， the compressive strength and penetration strength are higher， but the tensile strength is lower. The durability coefficient of RBCM after 30 cycles is still more than 50% after adding a little cement. Even without cement， the compactness and mechanical properties of the RBCM cushion still meet the requirements of the current cushion design index.