Tensile properties of high volume fly-ash (HVFA) concrete with limestone aggregate

摘要

This paper presents the results of an investigation into the tensile properties of high volume fly ash (HVFA) concrete. Prismatic concrete specimens made with 50% replacement of cement by fly ash were made and cured to simulate concreting in various practical environments during summer and winter in western Japan. The temperature inside the concrete as well as in the curing environment was recorded. The prismatic concrete specimens were subjected to uniaxial uniform tensile stress. The full tensile stress-strain response for HVFA concrete was determined. The maximum tensile stress and the tensile Young's modulus were estimated. The authors' previously established correlations between the uniaxial tensile strength and both the splitting tensile strength and the compressive strength were examined for HVFA concrete. It is evident that the tensile modulus calculated based on formulae provided in JSCE design codes can be significantly underestimated. In addition, the thermal properties of HVFA concrete were investigated. Using HVFA 50% replacement of cement resulted in 40% reduction in the temperature rise compared to the concrete without fly ash. Regardless of use of fly ash, limestone aggregate concrete resulted in approximately half of coefficient of thermal expansion of normal concrete.