Pozzolana

Historical use: Pozzolanas like Santorin earth used in Eastern Mediterranean since 500400 BC Romans fully developed limepozzolan pastes for Roman concrete Vitruvius mentions four types of pozzolana: black, white, grey, and red Roman port at Cosa built of pozzolanalime concrete under water Cosa’s three piers still visible in excellent condition after 2100+ years Geochemistry and mineralogy: Volcanic pumices and ashes contain highly porous glass Alterable nature limits occurrence to active volcanic areas Chemical composition varies based on regional volcanism Mineralogical composition determined by presence of phenocrysts and parent magma Presence of associated minerals like feldspar, leucite, quartz, and pyroxenes Modern use: Pozzolana extensively used in countries like Italy, Germany, Kenya, and China Used as addition to Portland cement Larger ranges in composition and physical properties compared to industrial byproducts Expected to expand due to exhaustion of industrial sources and technical advantages Controlled by local availability and competition with industrial byproducts Pozzolanic reaction: Chemical reaction in Portland cement containing pozzolans Basis of Roman concrete invented in Ancient Rome Acidbase reaction between calcium hydroxide and silicic acid Studies on blended Portland cements containing Santorin earth Sustainable development and climate change initiatives related to pozzolanic reactions References: Ludwig, U.; Schwiete H.E. (1963). Lime combination and new formations in the trasslime reactions Mortureux, B.; Hornain H.; Gautier E.; Regourd M. Comparison of the reactivity of different pozzolans Mehta, P.K (1981). Studies on blended Portland cements containing Santorin earth Damtoft, J.S.; Lukasik J.; Herfort D.; Sorrentino D.; Gartner E.M. (2008). Sustainable development and climate change initiatives Cook D.J. (1986) Natural pozzolanas. In: Swamy R.N., Editor (1986) Cement Replacement Materials