Title: Use of High Volume Fly Ash in Grouting Applications

Author(s): J. Mirza, K. Saleh, V. Roy and M. S. Mirza

Publication: Symposium Paper

Volume: 172

Issue:

Appears on pages(s): 281-298

Keywords: Admixtures, grout; mechanical properties; portland cements, rheological properties; water-reducing agents

DOI: 10.14359/6137

Date: 12/1/1999

Abstract:
Applications such as soil, rock, and oil-well grouting all require enormous amounts of cement and are therefore good examples of areas where high volumes of ground slag or pozzolans such as fly ash could partially replace cement to produce low-cost, environmentally safe and durable grouts. This paper presents the results of a detailed study of the grain size distribution, three rheological properties, and five mechanical properties of high-volume fly-ash grout (containing over 55% fly ash) with and without high-range water reducing admixtures (HRWRA) and/or anti-washout agents (AWA). The rheological properties are reported for eight water-solids ratios (W/S). The effects of HRWRA and AWA on the flow time of low W/S grouts and the stability of high W/S grouts are investigated for grouting. The results indicate that the addition of fly ash in cement grouts reduces the flow time, improves stability, reduces drying-shrinkage, attains similar or closer compressive and bond strengths as pure cement grouts at later ages. Moreover, when HRWRA is used for low W/S grouts, the latter destabilize (produces three layers of unknown composition) and in those cases AWA should be used.