Some Experiments on Properties of Concrete with Structural Light-weight Aggregate

Abstract

This paper is a report on the results of the fundamental experiment on the properties of the structural light-weight aggregate concrete. The strength of the 2 types of structural light-weight aggregates produced in Japan is represented by 10 per cent crushing value according to BS code 812. Concerning the bond strength, the maximum crack spacing that has a relation to the bond properties of reinforcing bars and concrete is discussed by means of tension pull-out type test using squarely-sectioned tensile specimens with round bars and several variant types of deformed bars. From the results in the test the following may be concluded: 1) The 10 per cent crushing value is approximately in proportion to the bulk specific gravity in the case of the aggregate used in this experiment. 2) In a high strength light-weight concrete whose compressive strength is larger than 400 Kg/cm2, the compressive and the tensile strength of concrete are so much affected by the strength of aggregate. 3) The maximum crack spacing of the structural light-weight concrete is linger than the normal concrete by 20 to 30 per cent. Therefore, it is confirmed that the bond property of the structural light-weight concrete is a little inferior to the normal concrete.