Development of high modulus concrete for special rigid structures

Abstract

This research objective is to develop high elastic modulus concrete over existing high strength concrete in order to apply to the structures those required special high rigidity or stiffness such as pier columns of high-speed rail projects and slender tall buildings to reduce the displacements under loadings. To increase the elastic modulus, high strength concrete can be adopted, however it is found to be ineffectiveness due to its high cost. In this research, the coarse aggregates using basalt rocks having size between 9.5 - 25 mm and EAF slag having size between 9.5 - 19 mm are used instead of conventional limestone aggregates. Both basalt aggregate and EAF slag exhibit better mechanical properties than limestone aggregate. The study considers two sources of basalt rock produced from different crushing plant in Northeastern of Thailand and EAF slag produced from steel manufactures in Eastern of Thailand. Based on appropriate mix design, the compressive strength as well as elastic modulus of the developed concrete specimen are tested at 14 and 28 days. The obtained results are compared with normal concrete specimen using limestone as coarse aggregate. It is found that the proposed concrete using EAF slag can significantly enhanced the elastic modulus with more cost effective than conventional high strength concrete.