Title: Use of Ground Bottom Ash and Silica Fume in Mortar and Concrete

Author(s): Kiyoshi Kohno and Hiroyuki Komatsu

Publication: Symposium Paper

Volume: 91

Issue:

Appears on pages(s): 1279-1292

Keywords: accelerated curing; ashes; autoclaving; compressive strength; curing; drying shrinkage; flexural strength; mix proportioning; permeability; silica; steam curing; tensile strength.

DOI: 10.14359/10122

Date: 2/1/1986

Abstract:
This paper describes an investigation of the use of industrial by-products such as bottom ash and silica fume with high silica content, as the admixture for mortar and concrete. The bottom ash used for this investigation was ground in a ball mill. At first, basic tests using mortars were conducted. Subsequently, the concretes containing different proportions of the two by-products were tested for strength development under accelerated curing, drying shrinkage, and water permeability. The results of the mortar strength tests indicate that the proper amount of ground bottom ash is about 5 percent if used to replace cement or 10 percent if used in addition to cement, and that of silica fume is approximately from 5 to 10 percent if used to replace cement and from 10 to 15 percent if used in addition to cement. When steam curing and autoclave curing are used, the concretes containing ground bottom ash and silica fume have higher early compressive strength than concrete without these materials. The coefficients of water permeability of the concretes using ground bottom ash and silica fume are lower than those of concrete without these materials. Paticularly, the water-tightness of silica fume concrete improved remarkably, although the concrete has a little higher drying shrinkage in comparison with concrete without silica fume. The use of these materials in amount of 5 to 10 percent to replace cement is effective for the improvement of concrete properties.