颗粒冲击引起混凝土材料的损伤

Damage of concrete caused by particle impacting

利用冲击球压法对标准养护室、室外、水以及5%Na2SO4溶液环境下的C30混凝土试件进行了试验。对混凝土应力—压痕尺寸关系和压痕形貌进行了评价和描述。试验结果表明:当冲击应力—压痕尺寸关系超过某一临界点后,压痕增大的速率远远大于应力的增长,Na2SO4溶液和水环境中的试件尤为明显;对压痕形貌的观察发现,室外和Na2SO4溶液中的试件其损伤最为强烈,具体表现为压痕周围发生了较为剧烈的颗粒脱落和松动。

Concrete will be affected in standard curing room, outdoors, in water and in 5% Na2SO4 solution.C30 concrete in these environment was experimentalized by sphere impacting.The relation of concrete impacting stress versus indentation size and the indentation morphology were evaluated and characterized.Experimental results indicate that the rate of indentation size increase exceeds much larger than that of stress increase when stress-indentation size surpasses certain critical point, especially in Na2SO4 solution and water.The observation of indentation morphology shows that the strongest specimen damage happens outdoors and in Na2SO4 solution,manifested as intense particle detachment and looseness around the indentation.