低热硅酸盐水泥对大坝混凝土性能的影响研究

Study on the Effect of Low Heat Portland Cement on the Performance of Dam Concrete

研究不同高镁低热硅酸盐水泥对大坝混凝土的力学性能、变形性能、热学性能、耐久性能等性能的影响。结果表明:优化配合比中水泥、粉煤灰及外加剂掺量后,减水剂掺量可降低至0.4%~0.6%,引气剂掺量降低至0.012%~0.016%,C_(180)40混凝土的单方用水量可降低至82 kg/m^(3)~83 kg/m^(3),65d龄期的自变值在-83.3×10^(-6)~-109.5×10^(-6)之间,绝热温升在27.5℃~28.7℃之间,各配比混凝土的抗压强度和极限拉伸值均能满足设计要求,且有较大富裕;合理提高水泥中Mgo含量,具有较明显的补偿混凝土自生体积变形的收缩效果。

Study the effects of different high magnesium and low heat Portland cement on the mechanical properties,deformation properties,thermal properties,durability and other properties of dam concrete.The results show that after optimizing the dosage of cement,fly ash,and additives in the mix proportion,the dosage of water reducing agent can be reduced to 0.4%~0.6%,the dosage of air entraining agent can be reduced to 0.012%~0.016%,and the unit water consumption of C_(180)40 concrete can be reduced to 82 kg/m^(3)~83 kg/m^(3).The autoregressive value at the age of 65 days ranges from -83.3×10^(-6)~-109.5×10^(-6),and the adiabatic temperature rise ranges from 27.5℃ to 28.7℃.The compressive strength and ultimate tensile value of each proportion of concrete can meet the design requirements and have a significant margin.Reasonably increasing the Mgo content in cement has a significant shrinkage effect that compensates for the self generated volume deformation of concrete.