玄武岩机制砂混凝土抗硫酸盐侵蚀性能-《建筑科学与工程学报》

文章信息/Info

Author(s):: QIAO Hong-xia, CHEN Zhi-chao, LIANG Jin-ke, LI Yuan-ke, NDAHIRWA Desire; Key Laboratory of Disaster Prevention and Mitigation in Civil Engineering of Gansu Province, Lanzhou University of Technology

Keywords:: basalt manufactured sand; ultrasonic velocity; relative dynamic elastic modulus; ratio of compressive strength

摘要:: 为了研究玄武岩机制砂混凝土抗硫酸盐侵蚀性能，采用了河砂（HS）、河砂+机制砂（HS+JZ）、机制砂（JZ）三个配比，设定了7.5%（质量分数）MgSO₄和15%（质量分数）MgSO₄两种溶液环境下进行干湿循环试验，通过测试质量损失率、超声波声速、相对动弹性模量和抗压强度比，结合内部裂缝与内部微观结构进行了分析。结果表明：18次干湿循环后在7.5%MgSO₄和15%MgSO₄两种溶液中3种混凝土的质量损失率分别增长到6.6%，5.5%，4.5%和8.9%，7.6%，6.5%；超声波声速值分别下降到3.600，3.684，3.800 km·s^-1和3.238，3.368，3.444 km·s^-1；相对动弹性模量分别降到64%，68%，76%和55%，57%，67%；抗压强度比分别降到0.84，0.83，0.88和0.72，0.75，0.78；河砂混凝土最终的侵蚀产物主要以白色纤维状结晶体钙矾石为主，玄武岩机制砂混凝土的侵蚀产物主要以白色石膏为主；玄武岩机制砂含少量石粉和自身的耐侵蚀性可有效提高混凝土抗硫酸盐侵蚀的能力。

Abstract:: In order to study the sulfate corrosion resistance of the basalt manufactured sand to concrete, three kinds of mix proportions including river sand (HS), river sand + manufactured sand (HS+JZ), manufactured sand (JZ) were selected, the dry and wet cycle tests were conducted under two solutions of 7.5% (mass fraction) MgSO_4?and 15% (mass fraction) MgSO_4. By testing the mass loss rate, ultrasonic velocity, relative dynamic modulus of elasticity and compressive strength ratio, combined with the internal cracks and internal micro structure, comprehensive factors were analyzed. The results show that after 18 dry and wet cycles, the mass loss rates of three kinds of concrete in two kinds of 7.5%MgSO₄ and 15%MgSO₄ are increased respectively to 6.6%, 5.5%, 4.5% and 8.9%, 7.6%, 6.5%. The ultrasonic velocities[JP] decrease respectively to 3.600, 3.684, 3.800 km·s^-1?and 3.238, 3.368, 3.444 km·s^-1. The relative dynamic moduli of elasticity decrease respectively to 64%, 68%, 76% and 55%, 57%, 67%. The ratios of compressive strength decrease to 0.84, 0.83, 0.88 and 0.72, 0.75, 0.78 respectively. The main erosion products of river sand concrete is mainly white fibrous crystals ettringite. The main erosion products of basalt manufactured sand concrete is mainly white gypsum. As a result of a few stone powder and its own corrosion resistance in the basalt manufactured sand, it can effectively improve the ability of concrete to resist sulphate erosion.