Characterization of Red Ceramic Waste for Application as Mineral Addition in Portland Cement

Abstract

This paper investigated the red ceramic waste originated from damaged sintered bricks as a potential source of pozzolanic mineral addition for portland cement. Physical, chemical, and mineralogical characterization of the red ceramic waste and clay raw material was conducted. The pozzolanic activity was identified through electrical conductivity, modified Chapelle, and Frattini tests, and verified by the evolution of axial compressive strength and apparent porosity in cementitious mortars produced with 30% of waste replacing portland cement. Results showed a low content of kaolinite (22%) in the clay used to produce the bricks and the complete decomposition of kaolinite after sintering. The red ceramic waste can be classified as a mineral addition with variable pozzolanicity by its ability to absorb calcium ions and pozzolanic material with medium reactivity, based on the ability to fix lime. The partial replacement of cement with 30% waste assigns a pozzolanic character to portland cement. The assessment of compressive strength and porosity in mortars over time supported the potential of using comminuted red ceramic waste as pozzolanic mineral addition in portland cement.