早强剂对钢渣-脱硫灰基胶凝材料的强度及水化性能影响

针对钢渣-脱硫灰基胶凝材料存在早期强度低的问题,研究不同早强剂对钢渣-脱硫灰基胶凝材料抗压强度及水化性能影响。结果表明:当脱硫灰掺量为15%,3 d抗压强度为3.65 MPa,比空白样降低了48.95%。利用生石灰、氯化钙、甲酸钙、硅灰、硫酸铝复合早强剂改性钢渣-脱硫灰基胶凝材料,其3 d抗压强度可达到17.89 MPa,是空白组试件的2.45倍,满足GB 175—2007《通用硅酸盐水泥》中复合硅酸盐水泥42.5级水泥抗压强度指标。通过XRD、SEM、FT-IR、XPS和DTG分析发现,水化产物主要是单硫型水化硫型硫铝钙、水化氯铝酸钙、水化硅酸钙和弗里德尔盐。

INFLUENCE OF ADMIXTURES ON STRENGTH AND HYDRATION PERFORMANCE OF STEEL SLAG & DESULFURIZATION ASH BASED CEMENTITIOUS MATERIALS

Aiming at the problem of low early strength of steel slag-desulfurized ash-based cementitious materials, the effects of different early strength agents on the compressive strength and hydration performance of steel slag-desulfurized ash-based cementitious materials were studied. Experimental research results showed that when the desulfurization ash content was 15%, the 3-day compressive strength was 3.65 MPa, which was 48.95% lower than the blank sample. Using quicklime, calcium chloride, calcium formate, silica fume, aluminum sulfate and other composite early-strength agents to modify steel slag-desulfurization ash-based cementitious materials, the 3-day compressive strength reached 17.89 MPa, which was 4.90 times that of the blank sample, and met the cement compressive strength requirements of composite Portland cement 42.5 grade, specified in China’s national standard, GB 175—2007. Through XRD, SEM, FI-RT, XPS and DTG tests, it was found that the main hydration products of cementitious materials were monosulfur hydrated calcium aluminum sulfide, hydrated calcium chloroaluminate, and hydrated calcium silicate, and Friedel’s salt.