Compressive Strength Property of Concrete Made from Crushed and Uncrushed Palm Kernel Shells

The cost of concrete materials in building and civil engineering project has been of concern to the society. These and other things led to the research on agricultural materials or by-products that are dumped as waste in our environment, causing pollution and congestion as possible replacement or substitute materials.
Previous works on crushed palm kernel shell shows that the strength determined have met with the building requirements. However, Due to low availability of PKS crushing machine in regions where PK are produced, there is a high reduction in the quantity of crushed PKS produced as manual crushing cannot meet up with the concreting demand if PKS were to be used for everyday constructional purposes.
Therefore, this research seeks to investigate the strength property of uncrushed PKS when used as coarse aggregate in concrete to improve on supply and avoid waste/delay caused by manual crushing techniques.
To assess this, 1:2:4 mix ratio was used at w/c of 0.6. Concrete cubes were cast using crushed PKS and uncrushed PKS as aggregate. Samples were cured and tested for compressive strength at 7 days and 24 days. The result showed that uncrushed PKS had better properties in terms of density and compressive strength than crushed PKS aggregate concrete. At 7 days uncrushed PKS had strength of 2.3N/mm2 while crushed PKS had strength of 2.1N/mm2 at the same age. The study therefore encouraged the use of uncrushed PKS for concreting instead of the crushed.