酸环境腐蚀对混凝土接触变形和损伤的影响

Influence of Environmental Corrosion on Contact Deformation and Damage of Concrete Materials

关键词:  环境腐蚀 压痕法 应力－应变关系 接触变形 损伤 混凝土 酸环境

Key words:  environmental corrosion,quasi brittle material,indentation,stress strain relation

摘要:

用Al2O3球压痕法研究了砂浆、混凝土和大理石在空气、水和盐酸溶液中的压痕应力－应变关系和接触损伤演变规律，结果表明：在水和空气中，混凝土的弹性模量和抗压强度是随着龄期的增长而增加的，其中，在水里，90d的弹性模量增加了67.87%、抗压强度增加了30.57%；在5％（体积分数）的盐酸中，混凝土90d的弹性模量降低了67.65%、抗压强度降低了12.87%。另外，对用压痕法评价混凝土材料表面腐蚀损伤程度的可行性和便易性也进行了验证。

Abstract:

Indentation stress strain curves and damage of concrete, mortar and marble in air, water and acid were investigated respectively with Al 2O 3 sphere contact. Elastic modulus and indentation stress strain curves were measured for different cases: (1) marble, mortar in water and 4%(vol) HCl for 5 min; (2) concrete in air, water and 5%(vol) HCl at the ages of 5,10,20,60, 90 d. Brinell hardness of marble and mortar before and after corrosion (in 2%(vol) HCl for 48 h) and compressive strengths of concrete in three different environment for 90 d were measured. The results indicated the acid environment has strong influence on mechanical properties of concrete materials, and the surface corrosion degree could be evaluated conveniently by sphere indentation method.