论文部分内容阅读
混凝土的损伤是一个多因素复合作用的结果．本文研究了引气（ＡＰＣ）和非引气（ＮＰＣ）高强混凝土在三分点加荷受弯和冻融循环同时作用下的损伤过程、机理．通过０％、１０％、２５％、５０％４个荷载比例作用下混凝土的抗冻性比较，分析了荷载和引气对混凝土抗冻性的影响．结果表明，荷载和冻融循环双因素作用下，荷载比例较大时，混凝土试件的破坏主要是荷载在冻融引起的微裂缝处产生应力集中，使微裂缝迅速扩展造成混凝土破坏．荷载比例较小时，冻融作用下孔隙水压力则是混凝土破坏的主要原因．
Concrete damage is the result of a multi-factor composite effect. In this paper, the damage process and mechanism of high-strength concrete (APC) and non-entrained gas (NPC) concrete subjected to bending and freezing-thawing cycles at the three points are investigated. Through the comparison of the frost resistance of concrete under the load ratio of 0%, 10%, 25% and 50%, the influence of load and bleed air on the frost resistance of concrete was analyzed. The results show that under load and freezing-thawing cycles, when the load ratio is large, the failure of concrete specimens is mainly caused by stress concentration in the microcracks caused by freezing and thawing, and the micro cracks are rapidly expanded to cause concrete failure. When the load ratio is small, the pore water pressure under freezing and thawing is the main cause of concrete failure.