蒸养温度、低碱速凝剂和硫铝酸盐水泥对混凝土性能的影响

Effects of steam curing temperature,low alkali accelerator and sulphoaluminate cement on concrete properties

为合理选择蒸养温度,提高模板周转率,改善经蒸养混凝土的后期力学性能,以C50混凝土为对象,研究了蒸养温度、低碱速凝剂和硫铝酸盐水泥对蒸养混凝土性能的影响,并与标养混凝土对比。结果表明:随蒸养温度升高,脱模强度大幅提高,但28 d的力学性能均降低,收缩率减小,徐变度和徐变系数均增大。低碱速凝剂和硫铝酸盐水泥均显著缩短混凝土的凝结时间、提高脱模强度。低碱速凝剂掺量为1%、硫铝酸盐水泥掺量为6%和20%时,经蒸养的28 d、56 d、90 d抗压强度均高于基准组标养的同龄期强度。

In order to reasonably select the steam curing temperature,improve the turnover rate of formwork and enhance the mechanical properties of steam cured concrete,taking C50 concrete as research object,the effects of steam curing temperature,low alkali accelerator and sulphoaluminate cement on the properties of steam cured concrete were studied,and then compared with standard curing concrete.The results show that:with the increase of steam curing temperature,the demoulding strength is improved greatly,while at 28 days the mechanical properties are reduced,the shrinkage rate is reduced,and the creep degree and creep coefficient are increased.Low alkali accelerator and sulphoaluminate cement can significantly shorten the setting time of concrete and improve the demoulding strength.The compressive strength at 28 d,56 d and 90 d after steam curing with 1%of low alkali accelerator,6%or 20%of sulphoaluminate cement were higher than those of the reference group at the same age.