AN INVESTIGATION ON THE MECHANICAL PROPERTIES OF OPC AMALGAMATED WITH CRAB CRUSTACEANS

Abstract

In this paper, an experiment was conducted on Ordinary Portland Cement (OPC) by partially replacing them with powdered crab shells to make an assembly of mortar cubes with 10, 20 and 30 percent crab volume by weight. These cubes are then mechanically tested for compressive and tensile strength and found that as the volume of crab powder concentration increased, the compressive strength decreased for the 3, 7 and 28 days curing period.

However, the tensile strength test had an interesting twist to the 28 days result where the strength increased as the concentration of crab volume in the mortar briquettes increased. This led to the speculation that crab additives could improve tensile properties in OPC mortar, making it feasible for secondary applications that include masonry and plastering.

The porosity of the agglomarated material also reveals that the water absorption capability increased as the concentration of crab increased which means that crab additives increased the porosity of OPC mortar, being more subservient to absorb more water as compared to pure OPC.

The pH level of the mortar paste was of an alkaline nature of more than 11 (litmus paper test) that is critical to resist carbonation in reinforced concrete.

Finally visual inspections noted the difference in texture and dampness in the demolding stage and the pattern of failure under the compression test was documented.