多孔混凝土在干湿交替作用下加速硫酸盐侵蚀的耐久性评价

Evaluation of Durability of Porous Concrete Under the Action Together with Wet-dry Cycling and Accelerated Sulfate Attacking

研究了干湿交替作用下加速硫酸盐侵蚀对植生型多孔混凝土耐久性的影响。采用正交实验方法,研究了净浆水胶比、矿粉掺量和骨料粒径三种因素对多孔混凝土抗硫酸盐侵蚀性以及对抗压强度的影响。试验通过将测量的超声波波速换算为相对动弹模量以评价多孔混凝土的硫酸盐侵蚀破坏程度。实验结果表明,在相同空隙率情况下,骨料粒径越小,抗硫酸盐侵蚀性能越好;水胶比在0.25～0.29的范围内,净浆水胶比越大,抗硫酸盐浸蚀性能越好;磨细矿粉掺量大于20%时,不利于提高多孔混凝土的抗硫酸盐侵蚀性能。

The influences of three factors, the water binder ratio W/B, the contents of ground slag powder and the particle size of aggregate, on the resistance to sulfate attack and compressive strength of porous concrete have been experimentally studied under the conditions of dry-wet cycling and sulfate attacking. And the loss of dynamic elastic modulus of porous concrete, which are get throuht calculating the data of measured velocity of ultasonic waes in tests, is taken for evaluation of the failume degree on sulfate attack. The vezults show that the less of aggregate particle size, the better of durability on sulfate attack; and the lager of W/B, the better of durability on sulfate attack when the W/B is in the range of 0.25-0.29; and when the content of ground slag is larger than 20%, there is a harmfulness for raising the resistance of porous concrete to sulfate attack.