Improving mortar properties using traditional ceramic materials ground to precisely controlled sizes

Abstract

The present work investigates the impact of particle size reduction of traditional ceramic mate rials as partial substitutes for Portland cement in mortars. Ceramic brick, ceramic tile, and stoneware were selected, with three particle sizes (D50 of 1, 5, and 15 μm) achieved through grinding operations adapted to each material grindability. The reactivity of ceramic powders was assessed via dissolution in saturated lime solution. Mortars were prepared with 10 % and 20 % cement mass replaced by ceramic powders ground to each fineness. The packing density of mortars was evaluated using the Compressible Packing Model. Compressive strength was measured at 1, 3, 7, and 28 days, and pore size distribution was analyzed by mercury intrusion porosimetry. Results indicated that ceramic tile required less grinding energy than brick and stoneware. High-energy grinding slightly altered the crystalline structure and increased amorphous content, enhancing reactivity with lime. Increased cement replacement with finer ceramic powders (D50 about 1 μm) improved strength, increased mesopores (50 nm), and reduced pore size threshold, attributed to filler and pozzolanic effects. A multiple linear regression model effectively described the influence of various variables on mortar strength with the interaction terms demonstrating the complexity of the interplay of the variables.This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001. The authors would like to thank the support from NUCAT-COPPE-UFRJ and CETEM in FRX and X-ray diffraction analyzes. The financial support from the Brazilian agencies CNPq, FAPERJ, and FAPEAM is also deeply acknowledged. Special thanks for support on the saturated lime dissolution test at the CRM Department in Madrid, Spain.Peer reviewe