摘要
海水和滨海盐渍土存在的硫酸根离子与混凝土反应将导致保护层膨胀剥落,从而使得氯离子传输距离缩短、钢筋混凝土更易腐蚀。对0~50%粉煤灰掺量、0~65%矿粉掺量混凝土开展实海暴露,同时将混凝土粉末浸泡于1%硫酸钠和海水溶液中,研究混凝土与硫酸根离子的反应量。试验结果表明:海水中的硫酸根离子进入混凝土内部,其1 d的反应量达到总反应量的50%,28 d后将达到反应平衡;其反应的硫酸根离子量超过总硫酸根离子量的84%。当粉煤灰掺量达到50%,矿粉掺量达到65%时,其抗压强度小于普通混凝土,但可以降低混凝土的硫酸根离子反应量5%~15%,从而有助于降低于混凝土的硫酸盐腐蚀风险。海洋潮汐区腐蚀混凝土的硫酸根离子反应量与海沙区相近,但高于大气区腐蚀混凝土。
Sulfate ions existed in seawater and saline soil would react with concrete and result to expansion spalling of concrete cover,which would shorten migration distance of chloride ions and accelerate the corrosion of reinforced concrete.Concretes with 0~50%fly ash,or 0~65%GGBS were prepared and exposed to marine atmosphere zone,tidal zone and submerged zone,and the powder from these concretes was immersed into 1%Na2SO4 and seawater for different time.The reacted sulfate ions with concrete and concrete powder were tested.The experimental results shown that reacted sulfate ions with concrete was 50%of total reacted ions after 1 day′s immersion,and wouldn′t increase with corrosion age after 28 days′immersion.The reacted sulfate ions content was higher than 84%of total penetration sulfate ions in concrete.The compressive strength of concrete with 50%fly ash or with 65%GGBS was less than control concrete.However,high dosage of fly ash and GGBS in concrete decreased 5%~15%of reacted sulfate ions concrete,which was helpful to lighten sulfate corrosion of concrete.Additionally,the sulfate ions reacted with concrete exposed to tidal zone was same as that to submerged zone,but higher than that to atmosphere zone.
作者
闫立忠
王潇舷
刘伟龙
YAN Lizhong;WANG Xiaoxian;LIU Weilong(Qinglian Railway LLC,Qingdao 266400,China;School of Civil Engineering,Qingdao University of Technology,Qingdao 266033,China)
出处
《混凝土》
CAS
北大核心
2019年第10期27-31,共5页
Concrete
基金
铁道部科研计划课题（2014G004-F）
国家自然科学基金（51678318）
