Investigation on material stability of spherical shaped EAF slag fine aggregate concrete for pavement during thermal change

摘要

For wider utilization of spherical shaped EAF slag in pavement concrete, a thorough investigation on the thermal properties of slag concrete is required since the traditional design approach for deformation behavior due to thermal stress might not be applied directly if the thermal properties of EAF slag concrete are different from normal concrete. In order to investigate the thermal properties and freezing and thawing resistance, concrete specimens were casted by replacing natural sand with spherical and angular shaped EAF slag fine aggregate at a volume ratio of 0.0, 0.3, 0.5 and 1.0 for the water to cement ratio (MC), slump and air content of 0.4, 5 cm and 5% respectively. Thermal properties such as thermal expansion, thermal conductivity, thermal diffusivity, specific heat and freezing and thawing resistance of casted concrete were tested after a curing age of 28 days. Results indicate that spherical shaped EAF slag concrete exhibits lesser thermal expansion, thermal conductivity, thermal diffusivity and specific heat in comparison to normal concrete although freezing and thawing resistance of angular shaped EAF slag concrete with higher slag replacement ratio is found larger. (C) 2019 Elsevier Ltd. All rights reserved.