摘要
基于室内浸泡试验,采用正交试验方法,通过分析单轴立方体抗压强度、弹性模量及抗腐蚀系数K三个指标,研究了不同温度(35℃、20℃、-15℃)条件下Na 2SO 4侵蚀对混凝土劣化性能的影响。研究结果表明:温度不同,Na 2SO 4侵蚀对混凝土劣化程度的影响不同,混凝土试块单轴立方体抗压强度、弹性模量及抗腐蚀系数K随着恒定浸泡温度的降低而降低;SEM结果显示,温度和浸泡时间影响了钙矾石晶体的产生及生成数量。钙矾石晶体生长过程中造成的结晶压力和微细针状晶体吸水膨胀在水泥石中产生的内应力,使得混凝土结构内部出现微裂缝,从而导致混凝土强度降低。
Based on the indoor immersion test,using the orthogonal test method,the effect of Na 2SO 4 erosion on the concrete deterioration performance under different temperature conditions(-35℃,20℃and-15℃)was studied.Three indicators were analyzed including the uniaxial cube compressive strength,the elastic modulus and the corrosion resistance coefficient K.The results show that Na 2SO 4 erosion exerts varied effects on the degree of concrete deterioration under different temperature conditions.Moreover,the uniaxial cube compressive strength,the elastic modulus and the corrosion resistance coefficient K of the concrete test block decrease as the constant immersion temperature drops.Besides,SEM results show that the quantities of ettringite crystals produced and generated are affected by temperature and immersion time.The crystallization pressure caused during the process of ettringite crystals growth and the fine acicular crystals generate internal stress in the hardened cement paste upon absorbency swelling,making micro-cracks witnessed in the concrete structure,and leading to a strength reduction in the concrete.
作者
郭佳庆
马艳霞
高英
孙昊
白继雄
GUO Jiaqing;MA Yanxia;GAO Ying;SUN Hao;BAI Jixiong(School of Civil Engineering,Qinghai University,Xining 810016,China;Qinghai Provincial Key Laboratory of Energy-saving Building Materials and Engineering Safety,Xining 810016,China;Qinghai Jinzuo Commercial Concrete Co.,Ltd.,Xining 810000,China)
出处
《硅酸盐通报》
CAS
北大核心
2020年第10期3184-3190,共7页
Bulletin of the Chinese Ceramic Society
基金
青海省科技厅应用基础研究项目(2018-ZJ-749)。
关键词
盐渍土
混凝土
硫酸钠侵蚀
抗压强度
钙矾石
温度
微观结构
saline soil
concrete
sodium sulfate attack
compressive strength
ettringite
temperature
micro structure
