Characterization of construction materials on the base of mortar waste, activated by aluminum anodization sludge and lime production waste

Abstract

Abstract The purpose of this study was to develop and to characterize new composites of construction materials (solid and hollow bricks and building blocks) manufactured from three different industrial wastes – nanoparticles of aluminum anodization sludge (65–90%), mortar’s production and application waste (0–15 wt%), and lime production waste (5–20%). All of them have pH values near 11–13.5, and therefore should be classified as hazardous materials. They have a meager percentage of recycling and actively contaminate industrial landfills and the surrounding environment. The mechanical properties of the developed composites far exceed the requirements of Brazilian construction standards. Thus, the axial resistance strength values varied between 0.81 and 6.98 MPa on the 3rd day of cure, 2.53–10.88 MPa on the 28th day and 5.62–15.86 MPa on the 365th day of open-air cure. The water absorption values decreased from 9.13 to 10.28% on the 28th day to 8.02–9.40% on the 90th day; the water resistance coefficient on the 28th day of cure was between 0.63 and 0.95; the dilatation coefficient decreased during 365 days from around 1.34–2.05% to 1.22–1.88%. The study of the physical-chemical’s composites strengthening processes by XRD, XRF, SEM, EDS and LAMMA methods showed a 30 decrease in the crystalline phase of the original mix with the synthesis of mainly amorphous and partly crystalline carbonates.