水泥类型对海砂混凝土在生物硫酸腐蚀下劣化影响的研究

Influence of Cement Type on Deterioration of Sea Sand Concrete Subjected to Corrosion of Biological Sulfuric Acid

采用硫铝酸盐水泥(SAC)以及普通硅酸盐水泥(OPC)制备海砂混凝土,采用T.t细菌(氧化硫硫杆菌)模拟不同pH(1.0,1.5和2.0)生物硫酸腐蚀,测试质量损失率、抗压强度、腐蚀层pH、Cl-固化率和孔结构,并通过SEM/EDS、XRD分析不同海砂混凝土在耐生物硫酸腐蚀性能上的差异。结果表明:在生物硫酸腐蚀下,OPC、SAC海砂混凝土部分水化产物分解,主要腐蚀产物为CaSO_(4)·2H_(2)O。在质量损失率、强度下降、氯离子固化和孔结构方面,SAC海砂混凝土抗生物硫酸腐蚀性能优于OPC海砂混凝土。

Two types of sea sand concretes were prepared with sulphate aluminum cement(SAC)and ordinary Portland cement(OPC),respectively.Herein,T.t bacteria(thiobacillus thiooxidans)was used to simulate biological sulfuric acid corrosive media with different pH values(1.0,1.5 and 2.0).Then,the effect of cement type on the degradation of sea sand concretes in simulated biological sulfuric acid corrosive media was characterized in terms of mass loss rate,compressive strength,pH value of corroded layer,fraction of solidified chlorides and pore.The results show that the hydration products of sea sand concrete with OPC or SAC were partially decomposed during the biological sulfuric acid corrosion,and the main corrosion product was CaSO_(4)·2H_(2)O.In biological sulfuric acid corrosive environments,the sea sand concrete with SAC presents better performance than that with OPC in terms of mass loss rate,strength deterioration,solidified fraction of chlorides and pore structure.