Comparative study of performance properties of ordinary portland cement (OPC) and pozzomix cement sandcrete blocks

Abstract

The study compared the performance properties of OPC and pozzomix cement sandcrete blocks in existing structures. Properties like compressive, water absorption, density and weights were determined and assessed to see how they enhance performance and its effect on durability of existing structures. Field survey research and experimental research designs were employed for the study. The study sampled eleven (11) research scientists at CSIR-BRRI and thirty-five (35) building contractors working with pozzomix cement and ordinary Portland Cement (OPC). 25 pozzomix cement and 25 OPC sandcrete blocks were used for experiment at CSIR-BRRI laboratory. Questionnaire, laboratory test and observation were used as data collection instrument. Comparatively, the performance properties of OPC and pozzomix cement sandcrete blocks were inconsistent with defects in some of the structures observed. Densities of OPC sandcrete blocks were averagely higher than those of pozzomix cement sandcrete blocks with both above the standard minimum density of 1500kg/m3

Compressive strength of OPC and pozzomix cement sandcrete blocks failed to meet the required minimum standard respectively, for all curing ages, but pozzomix cement sandcrete blocks performed better than OPC sandcrete blocks. The study further revealed that OPC sandcrete blocks have lower water absorption rate than pozzomix cement sandcrete blocks. Therefore, using both OPC and pozzomix cement sandcrete blocks for construction works will be economically, eco-efficiently and technically beneficial to Ghanaian construction industry with 18%-20% cost reduction on materials. It is recommended that the commercialisation and use of pozzomix cement sandcrete blocks can go hand in hand with OPC sandcrete blocks for all construction works with regard to standard specification in the construction industry.