Study of Radioactive Characteristics of Cement Pastes Blended with GGBFS

Abstract

This paper reports an experimental study carried out to investigate the effects of ground granulated blast- furnace slag (GGBFS) on radiation attenuation and mechanical properties of blended cements. Five cement mixtures were prepared with 0%, 10%, 15%, 30% and 40% of slag replacing the cement content and having water to cement ratio of 0.3, 0.29, 0.28 and 0.27 by weight, respectively. The cement pastes were tested for compressive strength after water curing at 1, 3, 7 and 28 days. The various hydration products were identified using x-ray diffraction (XRD), differential thermal analysis (DTA) and scanning electron microscope (SEM) techniques. In the same context, the radiation attenuation coefficients expressed as linear attenuation coefficient, µ, of the investigated specimens were also determined after 28 days of hydration. The utilized radiation source comprised 137Cs radioactive element with photon energy of 0.662 meV. In a similar manner, HVL and TVL for the tested samples were obtained. From the investigation, it has been revealed that the partial replacement of OPC on average 30% slag significantly increased compressive strength than the neat mixture at 28 days of curing. Although the enhancement of compressive strength upon replacing OPC with GGBFS, however the results of radiation parameters showed no significant effect of slag substitution on the attenuation of γ-rays.