关键词: 泵送混凝土, 常态混凝土, 干缩性能, 水胶比, 力学性能

Abstract: Hydraulic pumping concrete differs greatly from normal concrete in terms of mixture state and material dosage. These differences will be reflected in the performance of hardened concrete. In order to study the differences in mechanics and shrinkage properties of hydraulic pumping concrete and normal concrete, we designed three groups of comparative test. Results revealed that in the presence of given water-binder ratio, pumping concrete was superior to normal concrete in compressive strength, tensile strength, tension-compression ratio and elastic modulus with the increase of water-binder ratio; while under different water-binder ratios, the shrinkage rate of pumping concrete was still higher than that of normal concrete. Moreover, the shrinkage rate of pumping concrete and normal concrete at the age of 28d, 60d and 90d were affected significantly by water-binder ratio; whereas the shrinkage rate at the age of 3d and 7d were not affected obviously. The shrinkage of the two concretes developed rapidly in the early stage, but was slowly in later stage. The average growth rate of drying shrinkage is in a power function relationship with age.

Key words: pumping concrete, normal concrete, shrinkage performance, shrinkage rate, mechanical properties