养护制度和大掺量掺和料对混凝土干缩性能的影响研究

The Effect of Maintenance Institution and High Volume Admixtures on the Dry Shrinkage Properties of Concrete

养护是获得高性能混凝土的重要环节,针对混凝土所处的环境特点,研究了大掺量矿渣和粉煤灰混凝土的干缩性能以及养护制度对混凝土干缩性能的影响规律。结果表明,在相同养护制度下,掺矿渣和粉煤灰的混凝土各测试龄期干缩率相对基准混凝土试件减小约5%～20%,有利于改善混凝土的干缩性能;延长养护时间有利于改善混凝土的干缩性能,养护时间宜根据需要适当延长,一般情况下不宜低于3d,且养护时间和养护方法对大掺量掺和料混凝土显得尤为重要。

Maintenance is an important link for getting the high performance concrete,according to the real environmental features of concrete in practice.The dry shrinkage performance of concrete with high volume slag and fly ash and the effect of maintenance institution on the dry shrinkage performance of concrete are studied in this paper.Results indicate that,dry shrinkage rate of slag and fly ash concrete are lower than the blank by about 5%~20% in any age.Prolonging standard curing age is conducive to improving the dry shrinkage properties of concrete.Maintenance time should be lenghened appropriately according to the real situation,and it should not be less than 3 d generally,maintenance time and institution is particularly important to concrete with high volume admixtures.