混凝土抗盐冻性能试验

摘要

In order to study the influence of concrete strength grade, volumes of fly ash and slag powder, and air-entraining content on the frost-salt resistance of concrete, an accelerated freeze-thaw test of concrete in salt solution was carried out. The correlation between the air-entraining contents of fresh concrete and hardened concrete was validated through measurement of bubble parameters of hardened concrete. The variation of surface characteristics, relative dynamic modulus of elasticity, and cumulative amount of spalling of concrete with the number of freeze-thaw cycles were investigated. The influence of concrete strength grade, volumes of fly ash and slag powder, and air-entraining content on the frost-salt resistance of concrete was examined. The results shows that a higher concrete strength does not always improve the frost-salt resistance, the air-entraining content is the decisive factor influencing the frost-salt resistance of medium-and low-strength grade concrete, and the volumes of fly ash and slag powder should be controlled within an appropriate range.%为研究混凝土强度等级、矿物掺合料和含气量对其抗盐冻性能的影响，对混凝土进行了盐溶液条件下的快速冻融试验。通过硬化混凝土气泡参数测定验证了新拌混凝土含气量与硬化混凝土含气量之间的相关性，对混凝土外观、相对动弹性模量、累积剥落量随冻融循环次数变化规律进行了分析，研究了不同强度等级、矿物掺合料、含气量等因素对混凝土抗盐冻性能的影响趋势。结果表明：单纯提高强度等级并不一定利于混凝土抗盐冻性能的改善，对中低强度的混凝土而言，含气量是影响其抗盐冻性能的决定性因素；粉煤灰与矿渣粉的掺量应控制在一定范围内。