碳化环境下聚丙烯纤维陶粒混凝土抗氯离子渗透性能试验研究

Experimental study on chloride penetration resistance of polypropylene fiber ceramsite concrete under carbonization environment

混凝土碳化对其抗氯离子渗透性能会产生影响,采用电通量法研究聚丙烯纤维陶粒混凝土在碳化环境作用下的氯离子渗透性能。在不同碳化周期下,分别测试不同聚丙烯纤维掺量陶粒混凝土的碳化深度及电通量,利用电通量试验数据推导出相应的氯离子扩散系数,并对试件碳化深度与氯离子扩散系数进行拟合,得到氯离子扩散系数随碳化深度变化的经验式。试验结果表明,碳化作用对聚丙烯纤维陶粒混凝土抗氯离子渗透性能存在积极和消极两方面影响,总体上对陶粒混凝土抗氯离子渗透性能有积极作用;可以用三次多项式来模拟陶粒混凝土碳化深度dc和氯离子扩散系数D的关系,比较不同纤维掺量下的试验数据与公式计算数据,拟合情况较好,建立了碳化深度与氯离子扩散系数之间的关系。

Concrete carbonation has an effect on its chloride penetration resistance.Chloride ion permeability of polypropylene fiber ceramsite concrete under carbonization environment was studied by electric flux method.Under different carbonation cycles,the carbonation depth and electric flux of ceramsite concrete with different polypropylene fiber content were tested respectively.The corresponding chloride ion diffusion coefficient is derived from the experimental data of electric flux.The empirical formula was obtained by fitting the depth of carbonation with the diffusion coefficient of chloride ion.The results show that carbonation has both positive and negative effects on chloride permeation resistance of polypropylene fiber ceramsite concrete,and on the whole it has positive effects on chloride permeation resistance of ceramsite concrete.Cubic polynomials can be used to simulate the relationship between the carbonation depth“dc”of ceramsite concrete and the chloride ion diffusion coefficient“D”.