脱硫石膏基超硫酸盐水泥混凝土强度和抗碳化性能研究

研究了水泥用量、水胶比、砂率对超硫酸盐水泥混凝土力学性能和抗碳化性能的影响,采用X射线衍射(XRD)、扫描电镜(SEM)、傅里叶红外光谱(FT-IR)测试方法对比分析了超硫酸盐水泥混凝土与矿渣水泥混凝土的微观形貌和水化产物的差异。结果表明:当水泥用量为8%时,超硫酸盐水泥混凝土的力学性能较佳,但抗碳化性能较差;当水胶比为0.35时,超硫酸盐水泥混凝土的性能最佳;当砂率为40%时,超硫酸盐水泥混凝土的性能最佳;超硫酸盐水泥的主要水化产物是AFt和C-S-H凝胶,缺少硅酸盐水泥中常见的Ca(OH)2;相较于矿渣水泥混凝土,超硫酸盐水泥混凝土的微观结构致密性较差。

Study on the Strength and Carbonation Resistance of Desulfurized Gypsum-based Supersulfate Cement Concrete

The effects of cement dosage,water-binder ratio,and sand ratio on the mechanical properties and carbonation resistance of supersulfated cement concrete were studied,and the micromorphology and hydration products of supersulfated cement concrete and slag cement concrete were analyzed by X-ray diffraction(XRD),scanning electron microscopy(SEM)and Fourier transform infrared spectroscopy(FT-IR).The results show that when the dosage of cement is 8%,the mechanical properties of supersulfate cement concrete are better,but the carbonation resistance is poor.When the water-binder ratio is 0.35,the performance of supersulfate cement concrete is the best.When the sand ratio is 40%,the performance of supersulfate cement concrete is the best.The main hydration products of supersulfated cement are ettringite and calcium silicate hydrate,lacking calcium hydroxide commonly found in Portland cement.Compared with slag cement concrete,the microstructure of supersulfate cement concrete is less dense.