防护涂层对混凝土力学性能和耐久性的影响

Effect of protective coating on mechanical properties and durability of concrete

研究了涂覆水泥基渗透结晶型涂层和氟碳涂层对混凝土力学性能和耐久性的影响。试验结果表明:涂覆防护涂层对混凝土的抗压强度和劈裂抗拉强度无显著影响;氟碳涂层致密性好,具有较高的物理隔离作用,对混凝土的抗氯离子渗透性能、抗冻性能和抗碳化性能有明显的提升作用,且可大幅度减小同龄期混凝土的干缩;而水泥基渗透结晶型涂层与混凝土同属水泥基材料,对混凝土耐久性的提升极为有限,对收缩的减幅也较小。涂覆2类涂层后,混凝土的氮气渗透率未发生显著变化,表明带涂层的混凝土在气体压力梯度下仍具有较好的与外界气体交换的能力。

The effects of cement-based permeable crystallization coating and fluorocarbon coating on mechanical properties and durability of concrete were studied.The test results show that the coating has no significant effect on the compressive strength and splitting tensile strength of concrete.The results show that the fluorocarbon coating has good compactness and high physical isolation effect,which can significantly improve the anti-chloride penetration performance,frost resistance and carbonation resistance of concrete,and can significantly reduce the drying shrinkage of concrete.However,the cement-based permeable crystallization coating and concrete are both cement-based materials,so the improvement of concrete durability is very limited,and the reduction range of shrinkage is also small.The results show that the nitrogen permeability of concrete does not change significantly after the two kinds of coatings are applied,which indicates that the coated concrete still has a good ability to exchange with the outside gas under the pressure gradient.