Study on Durability of Concrete Structures Contained Low Quality Aggregates

点击翻译按钮获取中文摘要

Recentry, there is the shortage of high quality aggregate such as river sand, and there are some attempts to utilize some kinds of biproducts to the aggregate of concrete. So the cases that the low quality aggregates are used for concrete will increase.In this study, experimental investigations on the properties of concrete which containes low quality aggregates such as fine aggregate made from the crushed weathered granite , recycled coarse aggregate prepared by crushing old concrete and reactive aggregate, are performed.Mechanical properties and durability of concrete contained these aggregate were studied and at the same time, dynamic behaviours of reinforced concrete contained these aggregates were investigated.Mechanical properties of these concrete were almost the same as these of normal concrete made of high quality aggregate. But as for durability, some kinds of these concrete contained low quality aggregate showed quite low resistance to the repeats of freezing and thawing actions and this can not be improved by air entrainment.Dynamic behaviors of reinforced concrte beams made of low quality aggregate were not inferior to those of normal reinfored concrete beams, and there found the cases that the capacity of shear failure of reinforced concrete beam contained reactive aggregate were improved by the expansion of concrete caused by alkali-aggregate reaction. But to conform these phenomena in the actual circumstance, it is necessary to investigate for more long term test.