不同养护制度下水性聚氨酯改性再生混凝土毛细吸水性能研究

Study on the Capillary Water Absorption Performance of Waterborne Polyurethane Modified Recycled Concrete Under Different Curing Systems

受孔隙率高、微裂缝多等缺陷的影响,再生混凝土的力学性能与耐久性均比普通混凝土差。以水性聚氨酯为改性材料,制备聚灰比分别为0.5%、1.0%、1.5%、2.0%的混凝土试件,开展不同养护制度下水性聚氨酯改性再生混凝土(WPUMRC)毛细吸水性能试验研究。研究表明:随着标准养护时间的增加,WPUMRC的累积吸水量、初始毛细吸水率、后期毛细吸水率均先减小后增大,在14d标准养护-14d室内自然干燥养护制度下,WPUMRC的累积吸水量、初始毛细吸水率、后期毛细吸水率达到最小值。

Due to higher porosity,multiple microcracks and other defects,the mechanical properties and durability of recycled concrete are weaker than those of ordinary concrete.Used waterborne polyurethane as a modified material,concrete specimens with polymer cement ratios of 0.5%,1.0%,1.5%and 2.0%were prepared.Experimental studies were conducted on the capillary water absorption performance of waterborne polyurethane modified recycled concrete(WPUMRC)under different curing systems.Research shows that with the increase of standard curing time,the cumulative water absorption,initial capillary water sorptivity and second capillary water sorptivity of WPUMRC firstly decrease and then increase.Under the 14d standard curing-14d indoor natural drying curing system,the cumulative water absorption,initial capillary water sorptivity and subsequent capillary water sorptivity of WPUMRC reach their minimum values.