Suitability of some Ghanaian mineral admixtures for masonry mortar formulation

The suitability of masonry mortar for various constructional applications is dependent on some vital engineering properties and production cost. In a majority of masonry formulations, ordinary Portland cement (OPC) is the principal binding agent. However, the current trend of cement cost in Ghana has rendered masonry mortar formulation quite expensive. In this paper clay pozzolana produced from cost efficient local technology and limestone powder was used as mineral admixtures in cement. Physical and chemical properties of the mineral admixtures were analyzed. The particle sizes of the materials were also investigated. Binary and ternary pastes and mortars were formulated using some percentages of Clay Pozzolana (CP), Limestone (L) and Clay Pozzolana–Limestone (CP–L) to replace part of the expensive ordinary Portland cement. Water demand and setting time tests were determined on the binder paste whilst compressive strength test was performed on mortars cured in water for 7 and 28 days. Test results indicated that ASTM type M and S mortars could be formulated from binary and ternary mortar mixes.

▸ In this paper, clay pozzolana produced from cost efficient local technology and limestone powders were used as mineral admixtures in cement. ▸ Binary and ternary pastes and mortars were formulated and some mechanical properties were determined on the formulated pastes and mortars. ▸ Test results indicated that ASTM type M and S could be formulated from binary and ternary mortar mixes using either clay pozzolana or limestone or both. ▸ Utilization of the limestone and clay pozzolana for the formulation of both binary and ternary mortar mixes proved to be very economical as compared to the plain mortar.