Strength development of lime–pozzolana pastes with silica fume and fly ash

• Lime–pozzolana pastes (LPP) with ordinary strength has been produced.
• Inclusion of silica fume is necessary for LPP to gain high early strength.
• Water curing at 60 °C improves the 28-day strength of the LPP by 40%.
• Strength loss occurs in water-cured specimens during hydration time of 28–90 days.
• Carbonated outer shell in air-cured specimens reduces strength gain.

This study explores the lime–pozzolana pastes made from high calcium hydrated lime blended with type F fly ash and silica fume, with the total pozzolana content up to 40%. Research focuses on the development of the compressive strength by varying the water–binder ratio, powder proportioning, fineness of lime, and curing conditions. The lime–pozzolana cement shows good promise as a binder which can be used alongside the Portland cement. With lower unit weight and higher compressive strength per unit weight than the Portland cement paste, the lime–pozzolana pastes can reduce the weight of structural elements and the overall cost of structures.