关键词: 混凝土;酸雨侵蚀;损伤进程;弯曲荷载;微观分析

Abstract: The damage deterioration processes of the compressive mechanical properties of concretes under different bending loads in simulated acid rain solutions with a pH value of 2.0 were investigated by measuring the damage deterioration curves of the relative surface elastic modulus and relative dynamic elastic modulus of concretes.The result shows that the relative surface elastic modulus and relative dynamic elastic modulus of concretes under acid rain attack successively all undergo three distinguished stages respectively, namely accelerating deterioration, gradual deterioration, rapid deterioration and ephemeral increase, gradual deterioration, accelerating deterioration.The bending load accelerates the damage progress of acid rain attack on concretes, and the acceleration of corrosion process becomes bigger with bending stress level and corrosion time increase.Microscopic analysis show that this is because of that bending load can increase concrete cracks and accelerate acid rain corrosion products to quickly fall away from concretes, so that the further invading capability of acid rain erosion media into concretes is intensified.

Key words: concrete;acid rain attack;damage progress;bending load;microscopic analysis