【摘要】 为了对加速养护引起的普通混凝土抗氯盐渗透能力负效应进行改善,制作了4种掺矿物掺和料混凝土试件.在达到一定的初始强度后,试件被分别放入40,60和80℃水槽中进行加速养护.在28,100,200和300 d龄期,根据ASTM C1202试验标准测定了试件的电通量,同时还对部分试件进行了快速氯离子扩散系数和压汞实验.实验结果表明,加速养护会导致普通混凝土的抗氯盐渗透能力线性劣化,而通过掺加矿物掺合料能够改善混凝土的微观孔隙结构和负效应.对掺矿物掺合料混凝土而言,60℃是获得较优抗氯盐渗透能力的加速养护温度上限.20℃常温条件的预养护对减轻此负效应有利,同时随着测试龄期的增长混凝土中胶凝材料的不断水化负效应也得以减轻.更多还原

【Abstract】 Four mineral admixture concrete specimens were fabricated to study the negative effect improvements of accelerated curing on the chloride penetration resistance of ordinary concrete.After reaching different initial strengths,the specimens were placed in 40,60,or 80℃ water tanks for accelerated curing.The Coulomb values of the specimens were measured with ASTM C1202 experiment at 28,100,200,and300 d.Partial specimens were also selected for rapid chloride ion migration coefficient and mercury intrusion porosimetry experiments.The experimental results show that the accelerated curing for ordinary concrete linearly deteriorates the chloride penetration resistance,whereas the incorporation of mineral admixtures improves the concrete microscopic porestructures and negative effects.An upper temperature limit of60 ℃ of the accelerated curing is suitable for obtaining superior chloride penetration resistance for the mineral admixture concrete.Pre-curing at a normal temperature of 20℃ is beneficial for improving the negative effect,which is also alleviated with increasing testing age as a result of the successive hydration of binder materials in concrete.更多还原