大掺量矿物掺合料混凝土的干燥收缩与数学模型

Drying Shrinkage of High Volume Mineral Admixture Concrete and Mathematical Model

本文研究了矿物掺合料和膨胀剂对混凝土干燥收缩的影响。结果表明,在低水胶比等量取代55%水泥的情况下,单掺矿渣时混凝土的干燥收缩值最小,双掺矿渣和粉煤灰时混凝土干燥收缩值略有增加,复合掺加硅灰时将显著增大混凝土的干燥收缩,复合掺加膨胀剂有利于降低干燥收缩值。此外,建立了大掺量矿物掺合料混凝土干燥收缩的复合指数函数模型,该模型与实测值非常吻合。

This paper studied the influence of mineral admixtures and expansive agents on drying shrinkage of concrete. The results show that, under the condition of low water-binder ratio and equal replacement of 55% cement, the drying shrinkage of single-added slag concrete is minimum and that of double-added slag and fly ash concrete has a little increasing; when silica fume is added compositely, the drying shrinkage of concrete increases obviously; expansion agent that is added compositely is helpful to reduce the drying shrinkage of concrete; besides, composite index function model of high volume mineral admixture concrete is built and the measured value accords with the model well.