掺矿物掺合料混凝土ASTM C1202测试指标的相关性

为了探讨掺矿物掺合料混凝土的ASTM C1202测试指标的相关性,采用ASTM C1202标准测试了分别掺有粉煤灰、矿渣、硅灰的混凝土28 d和91 d的初始电流、6 h电通量以及氯离子渗透深度;分析了6 h电通量和初始电流、氯离子渗透深度的关系以及矿物掺合料和龄期对这些关系的影响规律.分析结果表明:3种矿物掺合料均能不同程度地降低混凝土的6 h电通量、初始电流以及氯离子渗透深度;龄期基本不影响掺矿物掺合料混凝土6 h电通量与初始电流之间的相关性;龄期对掺矿物掺合料混凝土氯离子渗透深度与6 h电通量的相关性影响较大.可以考虑用初始电流作为评价指标建立掺矿物掺合料混凝土抗氯离子渗透性的评价标准;宜采用长龄期试件作为测试对象评价掺矿物掺合料混凝土抗氯离子渗透能力.

Correlations of test parameters of concrete with mineral admixtures according to ASTM C1202

To investigate correlations of ASTM C1202 test parameters of concrete with mineral admixtures , concrete specimens were prepared with partial cement replaced by fly ash, ground blast furnace slag or silica fume. Charge passed in 6 hours, initial current and penetration depth of chloride ions were tested according to ASTM C1202 at age of 28 d and 91 d. Relations between 6 h charge passed and initial current, penetration depth of chloride ions and influences of mineral admixtures and age on these relations were analyzed. Results show that the incorporation of silica fume, fly ash or slag can reduce 6 h charge passed, initial current and chloride ions penetration depth to different extent; curing age doesn't affect correlation between 6 h charge passed and initial current of concrete with mineral admixtures but affects correlation between 6 h charge passed and chloride ions penetration depth significantly. Initial current can be used as evaluating parameter for chloride ions penetration resistant ability of concrete with mineral admixture. It is appropriate to evaluate chloride ions penetration resistant ability of concrete with mineral admixtures at a long curing age.