Experimental Investigation of Periwinkle and Palm-Kernel Shells as Partial Replacement of Coarse Aggregate in Concrete
1*Lawal A. A., 2Adebakin I. H, 3Agamah F. U., 4Oni A. F., 5Olopade S. O., 6Sonibare S. A., 7Rufus A. A., and 8Showunmi O. L.
1,*Department of Architectural, Yaba College of Technology, Yaba, Lagos State, Nigeria.
2,5,Department of Civil Engineering, Yaba College of Technology, Yaba, Lagos State, Nigeria.
3,4,Department of Urban and Reginal Planning, Yaba College of Technology, Yaba, Lagos State, Nigeria.
6Department of Building Technology, Yaba College of Technology, Yaba, Lagos State, Nigeria.
7,8,Department of Social Science, Yaba College of Technology, Yaba, Lagos State, Nigeria.
DOI: 10.36108/laujoces/6202.71.0141
Abstract
The increasing demand for sustainable construction materials has intensified the search for environmentally friendly alternatives to conventional concrete aggregates. This study investigates the mechanical performance of concrete produced with periwinkle shells (PWS) and palm kernel shells (PKS) as partial replacements for natural coarse aggregates. Concrete mixes were prepared using a nominal mix ratio of 1:1.5:3 and a water-cement ratio of 0.5, with PWS, PKS, and combined PWS-PKS replacing conventional coarse aggregate at levels of 10%, 15%, 20%, and 25% by volume. A total of 351 specimens comprising 117 cubes, 117 cylinders, and 117 beams were cast and tested for workability, compressive strength, splitting tensile strength, and flexural strength following standard procedures. Results indicated that workability decreased with increasing shell content due to the high water- absorption characteristics of the shell aggregates. Mechanical properties generally declined as the replacement level increased; however, the blended PWS-PKS concrete exhibited superior performance compared with single-shell replacements. At 28 days, the 10% combined PWS-PKS mix achieved a compressive strength of 19.3 N/mm² (which is above the minimum benchmark of 17 N/mm² as specified by ACI 318-19) closely approaching the control strength of 20.5 N/mm². Similar trends were observed for flexural and splitting tensile strengths. The study identifies 10–15% replacement as the optimum range for achieving acceptable engineering performance while promoting resource conservation and waste utilization. The findings demonstrate that periwinkle and palm kernel shells possess significant potential as sustainable lightweight aggregates for non-heavy structural and general construction applications.
Keywords: Compressive strength, Lightweight aggregate, Palm kernel shell, Periwinkle shell, Sustainable concrete