Rheological and mechanical performance evaluation of high performance mortar based natural pozzolan

Abstract

This paper presents an experimental study on the rheological and mechanical properties of High Performance Mortar (HPM) based on natural pozzolan (NP). The specific surface BET of NP was 370 m²/kg used with different contents by weight of cement (5, 10, 15 and 20%). Two (w/b) water-binder ratios (0.35and 0.40) were used, the dosage of Superplasticizer (Sp) was kept constant (0.32 by weight of cement). The experimental results show that rheological properties of HPM increased with increasing NP content when w/b kept constant, but the increasing of (w/b) ratio led to decrease of both yield stress and plastic viscosity of mixtures. The mechanical characteristics were improved with increasing NP content when w/b kept constant, but the increasing of (w/b) ratio led to decrease of both compressive strength. The optimal percentage substitution was 15% of NP, reducing CO2 emission by 20% for each cubic meter of mortar production.

Keywords

• mortar rheology
• natural pozzolan
• plastic viscosity
• yield stress