凝灰岩机制砂混凝土抗低温硫酸盐侵蚀性  

Sulfate resistance of concrete by machine-made tuff sand at low temperature

作　　者：温小栋[1] 蔡煜梁 赵莉[1] 冯蕾[1] 

机构地区：[1]宁波工程学院,浙江宁波315016

出　　处：《浙江大学学报（工学版）》2017年第3期532-537,共6页Journal of Zhejiang University：Engineering Science

基　　金：国家自然科学基金资助项目(11202111;51569035);浙江省自然科学基金资助项目(LY15E080014);宁波市科技局重大重点资助项目(2013C51004)

摘　　要：为了研究低温环境下凝灰岩机制砂对混凝土抗硫酸盐侵蚀性的影响,结合腐蚀介质及低温环境特点,采用10±1℃的硫酸钠/硫酸镁复合溶液模拟服役环境;利用电脉冲加速腐蚀介质迁移,对比分析腐蚀前、后试样的强度变化、腐蚀产物的物相等.结果表明:凝灰岩机制砂拌制试件比河砂拌制试件更容易受到低温硫酸盐侵蚀破坏;一定掺量的氢氧化钡可改善试件的抗硫酸盐侵蚀能力,但当掺量高于4%时,改善作用开始降低;低温硫酸盐侵蚀后机制砂拌制试件的腐蚀物以碳硫硅酸钙为主,河砂拌制试件的腐蚀物以钙矾石为主.从凝灰岩石粉的物相及机制砂混凝土孔结构探讨抗低温硫酸盐侵蚀能力弱化原因.该研究可以为硫酸盐区划环境下机制砂混凝土的耐久性设计提供一定参考.The service environment was simulated using a mixed solution of sodium sulfate and magnesium sulfate at the temperature of 10 ± 1 ℃ combining with corrosive medium and low temperature characteristics in order to study anti-sulfate erosion properties of concrete by machine-made tuff sand at low temperature.Meanwhile,electrical pulses were used to accelerate corrosive medium migration.After that,on the variation of strength and corrosion products of the specimens was compatatively analyzed before and after suffered corrosion.Results show that the sulfate erosion behavior of machine-made tuff sand is more serious than that of river sand at low temperature.In a certain range,the anti-sulfate erosion ability of the specimens improves with the increasing dosage of the barium hydroxide.However,if the dosage of barium hydroxide is more than 4%,the addition of barium hydroxide will reduce the improvement effect.After a period of sulfate attack at low temperature,the erosion product of the specimens made from machine-made sand is mainly composed of thaumasite,while that of river sand is mainly composed of Ettringite.Furthermore,the reason that why the machine-made tuff sand can reduce the sulfate resistance ability of concrete at low temperature was discussed from the mineral composition of tuff rock powder and porous structure of machine-made sand concrete.This study could provide a certain reference for the durability design of concrete by machine-made sand suffering sulfate ambient.

关 键 词：硫酸盐侵蚀 凝灰岩机制砂 滨海土壤 低温 加速腐蚀 

分 类 号：TU528[建筑科学—建筑技术科学]