Suitability of periwinkle shell as partial replacement of Bida natural stone in concrete production.

Abstract

The suitability of periwinkle shells as partial replacement of Bida natural stone in concrete production was investigated in this study, physical and mechanical properties of the periwinkle shells, Bida natural stone and sand were determined. The concrete specimens that were used for this research work are 150mmx150mm150mm concrete cube for compressive strength, three number of specimens were cast and cure for 7, 21 and 28days. Concrete cubes were prepared using proportion of 0:100, 10:90, 20:80 30:70, 40:60, 50:50 periwinkle shells to Bida natural stone by weight as coarse aggregate, The mix ratio used here is 1:2:4 and the w/c ratio of 0.55% was adopted as a standard for the experiment. Slump test were conducted on fresh concrete to examined the workability of the concrete, dry density and compressive strength test were carried out on the hardened concrete. The bulk density of periwinkle shells was found to be 603.10kg/m3 while that of Bida natural stone was 1625kg/m3. The concrete cubes with periwinkle shells 50:50 proportion is lighter and have lower compressive strength compared to those with lesser percentage replacement. Optimum compressive strength at 28days of curing are 26.8N/mm2, 19.93 N/mm2, 16.61 N/mm2, 11.23 N/mm2, 8.48 N/mm2 and 6.97N/mm2 at 0, 10, 20, 30, 40, and 50% respectively. Workability and the compressive strength decrease with periwinkle shells content. From this study, it can be concluded that periwinkle shell can be used as partial replacement of Bida natural stone in cocrete construction work especially in place were gravel is in short supply and periwinkle shell are readily available. It can be safely recommended that Periwinkle shells can be a very good substitute for Bida natural stones in concrete works, but the percentage replacements should not exceed the 20% threshold.