Properties of concrete with pumice powder and fly ash as cement replacement materials

• The effect of pumice powder and fly ash on concrete properties was investigated.
• Pumice powder and fly ash improved physical properties of concrete.
• Strength of concretes with pumice powder and fly ash were comparable to reference.
• Pumice powder and fly ash contributed to sulfate resistance of concrete.
• Pumice powder can be used in concrete where sulfate resistance is desired.

Turkey is rich in natural pozzolan and pumice is abundantly found in several regions of the country. In this study, pumice powder (PP) and fly ash (FA) were used as cement replacement materials and the effect of partial replacement of PP, FA and their blends by cement on physical, mechanical and durability properties of concrete was investigated. Test results showed both PP and FA addition resulted in lower mechanical strength at early ages, but comparable strength at later ages compared to the reference concrete. Replacement of cement with PP, FA and their blends resulted in concretes with decreased water absorption, sorptivity and void content and higher magnesium sulfate resistance compared to the reference concrete. Since pumice is abundantly found in Turkey, this material might be used as an additive in concrete applications or as a precaution against magnesium sulfate attack.