含不同矿物掺合料混凝土的硫酸盐腐蚀试验研究

混凝土在硫酸盐溶液中的腐蚀会对地下建筑造成严重的破坏。为了提高混凝土在地下水环境中抵抗硫酸盐腐蚀的能力,本文以掺粉煤灰、硅灰和矿粉的三种矿物掺合料混凝土为研究对象,开展了混凝土在15%硫酸钠溶液中的腐蚀研究。采用超声波平测法测得混凝土腐蚀60 d的腐蚀深度;此外,通过对比分析了不同掺合料混凝土腐蚀60 d的抗压强度。试验结果表明:掺10%掺量条件下,硅灰混凝土腐蚀深度最大,粉煤灰混凝土次之,矿粉混凝土最小,即矿粉对混凝土抗硫酸盐侵蚀能力的提升最有利;未腐蚀前,三种矿物掺合料混凝土的抗压强度从大到小依次为粉煤灰>矿粉>硅灰,腐蚀后,粉煤灰混凝土的抗压强度较腐蚀前有所提高,而掺硅灰和矿粉混凝土的抗压强度变化较小。

Experimental Research on Sulfate Corrosion of Concrete Containing Different Mineral Admixtures

Corrosion of concrete in sulfate solution will cause serious damage to underground buildings.In order to improve the sulfate resistance of concrete,in this paper,the concrete with fly ash(FA),silica fume(SF)and ground granulated blast slag(GGBS)were taken as the research object,the corrosion performance of concrete in 15% sodium sulfate solution was studied.Ultrasonic pulse velocity method was used to measure the corrosion depth and compressive strength of concrete.In addition,the compressive strength of concrete corroded with different admixtures for 60 d was compared and analyzed.The test results show that the corrosion depth of SF concrete is the largest under the condition of 10% admixture,followed by FA concrete and the minimum was GGBS concrete.In other words,the GGBS is the most advantageous to improve the sulfate corrosion resistance of concrete.For the un-corroded concrete,the compressive strength of concrete with three mineral admixtures is in the order of FA,GGBS and SF.After 60 days of sulfate corrosion,the compressive strength of fly ash concrete is higher than that before corrosion,while the change in compressive strength of concrete with silica fume and ground granulated blast slag is small.