盐冻作用下高钛重矿渣混凝土耐久性试验研究  

Experimental study on durability of high-titanium heavy slag concrete under salt freezing

作　　者：梁贺之 陈伟 杨贺 Liang Hezhi;Chen Wei;Yang He(China Water Resources and Hydropower Tenth Engineering Bureau Co.,Ltd.,Chengdu 610072,Sichuan,China;School of Civil and Architectural Engineering,Panzhihua University,Panzhihua 617000,Sichuan,China;China Railway Tunnel Stock Co.,Ltd.,Zhengzhou 450001,Henan,China)

机构地区：[1]中国水利水电第十工程局有限公司,四川成都610072 [2]攀枝花学院土木与建筑工程学院,四川攀枝花617000 [3]中铁隧道股份有限公司,河南郑州450001

出　　处：《钢铁钒钛》2022年第4期100-106,共7页Iron Steel Vanadium Titanium

基　　金：工业固态废弃物土木工程综合开发利用四川省高等学校重点实验室项目(SC-FQWLY-2019-Y-08,SC-FQWLY-2020-Y-06)。

摘　　要：考虑水胶比、粉煤灰掺量、复合盐溶液浓度三个因素,采用正交试验,研究不同因素对高钛重矿渣混凝土耐久性影响。试验结果表明:复合盐溶液浓度对高钛重矿渣混凝土的质量损失率和动弹性模量影响最大。在水胶比和粉煤灰掺量一定的情况下,随着冻融循环的次数增加,高钛重矿渣混凝土试块质量损失率逐渐增大,呈现指数函数变化趋势。随着冻融循环的次数增加,高钛重矿渣混凝土试块的动弹性模量快速减小,呈现负指数函数变化趋势。复合盐冻融循环下的高钛重矿渣混凝土试块的质量损失与动弹性模量的衰减的主要原因有两方面,一是NaCl和Na_(2)SO_(4)物理结晶产生的结晶拉力破坏;二是Cl−与高钛重矿渣混凝土水化产物发生化学反应产生氯铝酸钙,SO_(4)^(2−)与水化铝酸钙发生化学反应,产生钙矾石,导致高钛重矿渣混凝土试块内部结构劣化。Considering the three factors of water-binder ratio,fly ash content,and composite salt solution concentration,orthogonal experiments are used to study the influence of different factors on the durability of high-titanium heavy slag concrete.The experimental results show that the concentration of the composite salt solution has the greatest influence on the mass loss rate and dynamic elastic modulus of the high-titanium heavy slag concrete.For a certain water-binder ratio and fly ash content,when the number of freeze-thaw cycles increases,the mass loss rate of high-titanium heavy slag concrete specimens gradually increases,showing an exponential function change trend.With the increase in the number of freeze-thaw cycles,the dynamic elastic modulus of the high-titanium heavy slag concrete test block decreases rapidly,showing a negative exponential function change trend.There are two main reasons for the mass loss and the attenuation of dynamic elastic modulus of the high-titanium heavy slag concrete test block under the composite salt freeze-thaw cycle.The first is the destruction of crystal tension caused by the physical crystallization of NaCl and Na_(2)SO_(4);the second is the chemical reaction between Cl^(−)and the high-titanium heavy slag concrete hydrate to produce calcium chloroaluminate,and the chemical reaction of SO_(4)^(2−)with calcium aluminate hydrate to produce ettringite,resulting in the deterioration of the internal structure of the high-titanium heavy slag concrete test block.

关 键 词：高钛重矿渣 混凝土 耐久性 复合盐 冻融循环 动弹性模量 

分 类 号：X757[环境科学与工程—环境工程] TU528[建筑科学—建筑技术科学]