Title: Mixture Proportioning for Highly-Flowable Concrete Incorporating Limestone Powder

Author(s): K. Sakata A, T. Ayano, and A. Ogawa

Publication: Symposium Paper

Volume: 153

Issue:

Appears on pages(s): 249-268

Keywords: aggregates; limestone; mix proportioning; segregation; slump tests; viscosity; water content; Materials Research

DOI: 10.14359/1073

Date: 6/1/1995

Abstract:
The concept of highly-flowable concrete was developed from the transformation of underwater concreting ideas to the concreting of structures on land. Therefore, the general properties of highly-flowable concrete are similar to those for concreting under water. The viscosity of highly-flowable concrete is high so that segregation of the coarse aggregate from the concrete can be eliminated. The slump flow of highly-flowable concrete is greater than 600 mm so as to increase its flowability. The slump flow is defined as the diameter of slumped concrete. The distinctive feature of the mixture is that a larger proportion of fine material is used in it. The high viscosity and large amount of fines increase its resistance to segregation. In the method of mixture proportioning of highly-flowable concrete proposed by the authors, a high-range, water-reducing admixture (HRWRA) is used to increase the slump flow. Furthermore, a segregation-reducing agent is used to minimize the segregation, although a large proportion of fines somewhat increases the viscosity of concrete. Limestone powder, which is a relatively low reactive material, is used to reduce the heat of hydration and shrinkage. In the proposed method of mixture proportioning, it is possible to choose the required average strength, water content, and fine aggregate-total aggregate ratio to suit special and particular conditions of concrete structures under various environmental conditions.