EFFECTS OF VOLCANIC TUFF AS A PARTIAL REPLACEMENT FOR CEMENT ON THE COMPRESSIVE STRENGTH OF CONCRETE

This study examined the use of volcanic tuff from Isparta (Turkey) Central Gelincik Village as a mineral admixture in the production of concrete. Chemically, the volcanic tuff is 80.5% SiO2, Al2O3, Fe2O3 and therefore matches the values needed for F-type fly ash in the ASTM C 618 standards, and meets the >= 70% requirement of total major oxides according to TS EN 450 standards. In the study, for concrete classes C20, C30 and C40, 9 mix samples were prepared at 10, 15 and 20% replacement rates and tested at 28 and 90 days for uniaxial compressive strength. The most suitable replacement ratio (apart from deviation in the V40/10 series) was found to be 20%. When the 20% replacement ratio is accepted, using volcanic tuff to make 1 m(3) of concrete saves 65 kg cement in C20, 84 kg in C30 and 108 kg in C40 concrete.