Flexural Properties of Concrete Pavement with Fly Ash Replacement of 40% Incorporating Limestone Powder

Thermal power plant has occupied 90% of electric power supply after the earthquake disaster in Japan. Hence amount of coal-ash has increased gradually. Coal-ash, especially fly-ash, should be used for civil infrastructures, and concrete pavement must be a typical application using fly-ash. Fly-ash is a pozzolanic material, so it can contribute to various properties, such as strength development at mature age. The strength development at early age, however, is significantly slow and may negatively affect traffic service. Early strength may be improved when limestone filler is mixed in fly-ash concrete. In addition, the fly-ash concrete made with limestone aggregate may be recyclable as raw material for cement production. This study aims at developing the fly-ash pavement concrete which can make a traffic opening early and can be recycled. The paper describes the flexural strength properties of pavement concrete made with fly-ash of 40% replacement of cement. The result indicates the flexural strength at early age can be improved by using limestone filler, and assures sufficient strength development for traffic service at age of 2 days. In addition, the report shows flexural fatigue strength of the fly-ash pavement concrete is equal to or higher than the durability of conventional concrete pavement.