恶劣环境下机制砂混凝土的强度和耐久性能

在对原材料进行性能测试和混凝土配合比试验的基础上,对C30机制砂混凝土开展了高温和冻融循环试验.对比研究了冻融循环、冻融循环后酸侵蚀和碱侵蚀3种情况下机制砂混凝土强度、相对动弹模量的变化规律;对比研究了高温、高温后酸侵蚀和碱侵蚀3种情况下机制砂混凝土强度、相对动弹模量的变化规律.结果表明:在试验温度和冻融次数范围内,机制砂混凝土在高温和冻融循环后抗压强度、相对动弹模量显著降低,并随温度和冻融循环次数的增加其降低幅度有增大趋势;机制砂混凝土在高温和冻融循环后,耐酸、碱侵蚀性能明显降低,温度越高、经受的冻融循环次数越多,其耐酸、碱侵蚀能力越低,且以耐酸侵蚀能力为最低.

Strength and Durability of Concrete with Manufactured Sand in Severe Environment

Nowadays, few people investigated the strength and durability of concrete with manufactured sand in severe environment. Experiment studies on C30 concrete with manufactured sand were carried out under condition of high temperature and freeze thaw cycles based on the testing of raw materials performances and concrete mix proportion. Comparative studies on the changing laws of the strength and the relative dynamic elastic modulus of concrete with manufactured sand were made in some cases, including high temperature and freeze thaw cycles, acid corrosion after high temperature and freeze thaw cycles and alkali corrosion following high temperatures and freeze thaw cycles. The results of tests indicate that the strength and the relative dynamic elastic modulus of concrete with manufactured sand decreases markedly with the increase of temperature and the number of freeze thaw cycles. The acid and alkali resistance of concrete with manufactured sand is also remarkably weakened due to the action of heating and freeze thaw cycles. The acid and alkali resistance, especially the acid resistance of the concrete lowers with the increase of temperature and the number of freeze thaw cycles.