大温差、大湿差环境下硫酸钠半浸泡混凝土抗压与微观特性

研究了西部大温差和大湿差的自然环境下,早期受5%和10%两种浓度硫酸钠溶液半浸泡28 d、56 d、84 d、112 d混凝土抗压强度。结果表明:与不浸泡试样28 d抗压强度相比,随着半浸泡时间的延长,不同浓度硫酸钠溶液半浸泡试样的抗压强度均呈递减趋势。10%硫酸钠溶液半浸泡试样28 d抗压强度损失达27.2%,半浸泡后期其抗压强度与5%溶液浓度半浸泡试样差别不大。扫描电镜(SEM)和XRD测试结果表明:半浸泡试样暴露于空气中的部分发生了无水硫酸钠结晶腐蚀,这也是半浸泡试样抗压强度降低的主要原因之一。

Compressive and Microscope Property of Concrete Partially Submerged in Sodium Sulfate Solution under Large Temperature and Relative Humidity Difference Environment

Under natural large temperature and relative humidity difference in the west of China,compressive strengths of twenty-eight days, fifty-six days, eighty-four days and hundred -twelve days for ordinary concrete partially submerged in 5% and 10% sodium sulfate solution at its early stages were studied, the results show that compressive strengths of specimens partially submerged in different concentrations of solution gradually decline as the extension of partially exposed time after comparing with that of unsubmerged specimens. Compressive strength of twenty-eight days for specimen partially submerged in 10% sodium sulfate solution decrease by 27.2%, however the compressive strengths have no obvious difference with that of 5% solution as the extension of partially exposed time. SEM and XRD show that sodium sulfate crystallization erosion happens to the partially exposed area, and results in large compressive strength loss.