磷酸镁水泥基材料薄层修补结构抗冲击性能研究

Research on impact resistance of magnesium phosphate cement-based thin layer repaired structure

采用磷酸镁水泥基修补材料(MPC修补材料)作为薄层修补结构的面层材料,强度等级为C50的混凝土作为基层混凝土,研究了MPC修补材料的修补层厚度、基层混凝土的界面粗糙度、钢纤维掺量以及盐冻条件对薄层修补结构抗冲击性能的影响。结果表明:随着修补层厚度以及基层混凝土界面粗糙度的增加,薄层修补结构的抗冲击性能提高;随着钢纤维掺量的增加,薄层修补结构的抗冲击性能提高,1、2、3、4、5 cm修补层厚度的钢纤维最佳掺量分别为0.4%、0.6%、0.8%、1.0%和1.0%,抗冲击性能较无钢纤维的薄层修补结构分别提高了125.6%、123.2%、121.8%、147.2%和144.2%;90次盐冻循环后,1、2、3、4、5 cm修补层厚度的薄层修补结构抗冲击性能较非盐冻条件下分别降低了75.6%、52.0%、32.7%、33.3%和28.2%。

Using magnesium phosphate cement-based(MPC)repair material as the surface material of thin layer repair structure,and the C50 concrete as the base concrete,studied the influence of repair thickness,base concrete's interface roughness,steel fiber content and salt freezing conditions on the impact resistance of thin layer repair structure.The results show that,with the increase of the repairing thickness and surface roughness of the base concrete,the impact resistance of the thin-layer repairing structure improves.With the increase of the content of steel fiber,the impact resistance of the thin-layer repaired structure improves.When the optimal content of steel fiber is added,the optimal content of steel fiber of the 1~5 cm thin-layer repaired structure is 0.4%,0.6%,0.8%,1.0%and 1.0%and the impact resistance increases by 125.6%,123.2%,121.8%,147.2%and 144.2%respectively than the thin layer structure without steel fiber.After 90 times of salt-freezing cycle,the impact resistance of the thin layer repaired with thickness of 1~5 cm was reduced by 75.6%,52.0%,32.7%,33.3%and 28.2%respectively than that under non-salt frozen condition.