XRD investigation of cement pastes incorporating concrete floor polishing waste

Investigação por DRX de pastas de cimento com incorporação de resíduo de polimento de pisos de concreto

Abstract

The X-ray diffraction (XRD) technique has been widely used in order to investigate anhydrous and hydrated cement phases. In this study, XRD was used in order to analyze the concrete floor polishing waste (CFPW) and cementitious paste containing CFPW. The diffractograms obtained were compared with literature data in order to identify the phases of analyzed materials. Rietveld refinement of XRD pattern of paste containing 12% of CFPW addition was also carried out, in order to analyze calcite and aragonite structures, as these phases are calcium carbonate polymorphs that contribute to matrix filling. XRD pattern of CFPW showed a high concentration of carbonate phases, indicating that the concrete waste was carbonated. The CFPW addition in the cementitious matrix changed the hydrate cement products, as it induced the formation of carboaluminate phases, such as hemicarbonate. Calcite, which is a stable phase, contributed better to the filler effect, as its particles have higher volume than aragonite.

Keywords:
cementitious hardened paste waste; XRD qualitative analysis; Rietveld refinement