水泥稳定废砖集料的强度特性研究

Strength Characteristic of Cement Stabilized Crushed Brick Aggregate

将废砖集料按0、30%、60%和100%的比例替代天然碎石配制4种水泥稳定废砖混合料级配,并按4%和5%水泥剂量拌和成型试件,测试水泥稳定废砖的击实特性、抗压强度、劈裂强度和抗压回弹模量。结果表明:CBA存在大量的孔隙与微裂缝,导致其强度低、吸水率大;由于CBA的密度小、吸水率大,导致水泥稳定废砖的最大干密度随着CBA含量的增加而增大,最佳含水量则逐渐减小;当水泥剂量相同时,各龄期水泥稳定废砖的无侧限抗压强度和回弹模量均随CBA含量的增加而降低,劈裂强度则随CBA含量的增加而增加;水泥稳定废砖的抗压回弹模量与无侧限抗压强度存在良好的线性关系。

Taking the place of natural crushed stone with crushed brick aggregates, which is known as CBA, by 0, 30%, 60%and 100%to configure 4 kinds of cement stabilized crushed stone mixture gradations, and then mixing cement by 4%and 5% for molding specimens in order to test the compaction characteristics, compressive strength, splitting tensile strength and compressive rebound modulus of cement stabilized crushed stone. The results show that：there are a lot of pores and micro-cracks in CBA leading to low intensity, high water absorption;the low density and high water absorption of CBA lead to that the maximum dry density of cement stabilized crushed stone increases with the increase of CBA percentage, meanwhile the optimum moisture content gradually decreases;with the same dose of cement, the unconfined compressive strength and resilience modulus of cement stabilized crushed stone with each age decreases with the increase of CBA percentage, the splitting strength increases with the increase of CBA percentage; there is a good linear relationship between the compressive rebound modulus and unconfined compressive strength of cement stabilized crushed ston.