Technical quality of solid bricks made using clayey earth with added coffee grounds and fly ash

This paper analyses the effects of addition organic (coffee grounds) and inorganic (fly ash) residues to a clayey soil rich in quartz other silicates used as raw material brick production. To this end mineralogy, texture, durability physical mechanical properties solid bricks fired between 800 1100 °C were studied. The results show that firing temperature increased, phyllosilicate content decreased mullite appeared. matrix became less birefringent due gradual vitrification samples, especially after 950 °C. Vitrification resulted more compact, porous samples. did not affect but it alter certain parameters such colour porosity. largest differences detected fly ash, which usually caused whitish patina develop on surface bricks, while highest porosity values with coffee grounds, significantly reducing bulk density. increase improved resistance all regardless their composition.