Properties of Periwinkle-Granite Concrete

Abstract

The suitability of the shells from periwinkle, a small gastropod sea snail (mollusc), for use as partial replacement of granite in concrete was investigated. Physical and mechanical properties of the shells and well-graded granite chippings were determined and compared. Concrete cubes were prepared using 1:0, 1:1, 1:3, 3:1 and 0:1 proportions of periwinkle shells and granite chippings by weight, as coarse aggregate. Compressive strength tests were carried out on the periwinkle-granite concrete cubes. The bulk density of the periwinkle shells was found to be 1353kg/m3 while that for granite was 2644kg/m3. The ten percent fines and aggregate crushing values were 26KN and 64% respectively for periwinkle shells while for granite they were 114KN and 18%. Concrete cubes with periwinkle shells alone as coarse aggregate were lighter and of lower compressive strengths compared to those with other periwinkle:granite proportions. The 28-days density and compressive strength were 1824kg/m3 and 12.12N/mm2 respectively. Density, workability and the compressive strength of periwinkle concrete increased with increasing inclusion of granite chippings. It could be concluded from this study that periwinkle shells could be used as partial replacement for granite in normal construction works especially in places where granite is in short supply and periwinkle shells are readily available. (Journal of Civil Engineering, JKUAT: 2002 8: 27-36)