PERMIT离子迁移方法是目前唯一可现场测定混凝土保护层抗氯离子渗透性的试验方法。研究了混凝土孔溶液中阴离子和饱水程度对于PERMIT测量结果的影响。与氯离子相比,硫酸根及氢氧根等其他阴离子对测试结果的影响可以忽略,PERMIT测定的氯离子渗透性基本不受混凝土孔溶液成分影响。混凝土饱水程度对测量终点时间有显著影响,对电导变化率和氯离子扩散系数测定也有影响,但不显著。
PERMIT Ion Migration Test is the method testing the resistance of covercrete to the penetration of chloride ions in-situ.The effects of anions in pore solution and water saturation degree on the testing results of PERMIT Ion Migration Test are studied.The measurement of concentration of the outer chamber solution shows that both the ■ and OH-are neglectable for the testing of conductivity compared with Cl-,so the pore solution of concrete does not affect the PERMIT Ion Migration Test.Water saturation degree of covercrete has significant influence on the lag time of steady state,but has little effect on the changing rate of conductivity and testing result of the chloride diffusion coefficient.