辅助性胶凝材料对海水海砂混凝土碱硅酸反应特性的影响  

Influence of Supplementary Cementitious Materials on Alkali-Silicate Reaction Characteristics of Seawater and Sea Sand Concrete

作　　者：王德辉 张奇志 龚青南 罗素蓉[1] WANG Dehui;ZHANG Qizhi;GONG Qingnan;LUO Surong(College of Civil Engineering,Fuzhou University,Fuzhou 350116,China)

机构地区：[1]福州大学土木工程学院,福州350116

出　　处：《硅酸盐学报》2023年第11期2955-2965,共11页Journal of The Chinese Ceramic Society

基　　金：国家自然基金青年科学基金项目(51608187);国家自然科学基金面上项目(52078139)。

摘　　要：近些年,海水海砂混凝土的特性是一个研究热点,鲜有人关注海水海砂混凝土的碱硅酸反应。为了阐明辅助性胶凝材料对海水海砂混凝土碱硅酸反应特性的影响,采用单一质心法设计了水泥-偏高岭土-粉煤灰-矿粉四元胶凝材料,研究辅助性胶凝材料对海水海砂混凝土的碱硅酸反应(Alkali-silica reaction-ASR)产物、孔结构、孔溶液pH值和碱离子含量、膨胀率的影响。结果表明:海水海砂混凝土碱硅酸反应的非晶态产物ASR-P1(K_(0.52)Ca_(1.16)Si_(4)O_(8)(OH)_(2.84)·1.5H_(2)O)和晶态产物Na-shlykovite(NaCaSi_(4)O_(8)(OH)_(3)·2.3H_(2)O)的含量与其辅助性胶凝材料中活性SiO_(2)、Al2O_(3)含量成反比。在不同胶凝材料组成下,25%偏高岭土+25%粉煤灰+50%水泥制备浆体的pH值最低,Na^(+)、K^(+)、Ca^(2+)含量最小,ASR-P1和Na-shlykovite含量最低,孔隙率最大,有害孔和多害孔含量最低,14 d和28 d膨胀率均为最小。本研究可为海水海砂混凝土的胶凝材料组成设计提供理论参考,并提高海洋工程海水海砂混凝土结构的使用寿命。The characteristics of seawater sea sand concrete become a recent research issue,while the alkali-silica reaction(ASR)of seawater sea sand concrete is still unclear.To clarify the influence of supplementary cementitious materials on the alkali-silica reaction characteristics of seawater and sea sand concrete,the cement-metakaolin-fly ash-slag cementitious materials were designed by a simplex centroid design method.The effect of supplementary cementitious materials on the ASR products,pore structure,pore solution pH value,alkali ion content and expansion rate of seawater and sea sand concrete was investigated.The results show that the content of the amorphous product ASR-P1(K_(0.52)Ca_(1.16)Si_(4)O_(8)(OH)_(2.84)·1.5H_(2)O)and the crystalline product Na-shlykovite(NaCaSi_(4)O_(8)(OH)_(3)·2.3H_(2)O)in seawater and sea sand concrete are inversely proportional to the content of active SiO_(2)and Al 2O_(3)in supplementary cementitious materials.Among the seawater and sea sand concretes with different cementitious materials,the pH value of paste prepared with 50%cement+25%metakaolin+25%fly ash and the contents of Na^(+),K^(+)and Ca^(2+)are the minimum values.As a result,the content of ASR-P1 and Na-shlykovite,the content of harmful pores and multi-harmful pores are the minimum values,as well as the porosity is the maximum value,thus resulting in the minimum expansion rate of the paste prepared with 25%metakaolin+25%fly ash+50%cement at 14 d and 28 d.This paper can provide a theoretical basis for the design of cementitious material composition of seawater and sea sand concrete,and improve the service life of seawater and sea sand concrete structure in marine engineering.

关 键 词：海水海砂混凝土 碱硅酸反应 无定形产物 结晶型产物 膨胀率 

分 类 号：TU528[建筑科学—建筑技术科学]