The Effect of Pulverised Fuel Ash on the Strength of Pavement-Quality Concrete

摘要

Pulverised fuel ash has been recognised for many years as being beneficial in concrete for certain purposes, particularly in mass concrete. To assess its possible applications in concrete road construction a study has been made of the effects on the strength of pavement-quality concrete of using a selected pulverised fuel ash as a cement-replacement material. The development of indirect-tensile, flexural and compressive strengths has been followed from an age of 18 hours to 1 year on various concrete mixtures containing up to 180 kg/cubic meters of ash. The low early strengths normally associated with such mixtures were as much as one-third less than control mix strengths at about 7 days but some ash-modified mixes became more than 30 per cent stronger than the appropriate control mix at one year. Values of strain capacity have been determined by two methods and have shown that at early ages the risk of cracking which is mainly the result of thermally induced strains is increased in ash-modified mixes. (Copyright (c) Crown copyright 1981.)