Influence of Crushed Oyster Shells as Partial Fine Aggregate Replacement on the properties of Concrete using different types of Portland Cement/ Patricia Anne B. Almeda [and five others].

Thesis (Undergraduate)

College of Engineering-- Bachelor of Science in Civil Engineering, Technological University of the Philippines, 2019.

The increasing volume of oyster shell wastes in the Philippines greatly poses a threat to both humans and the natural environment. The goal of this study is to innovate and recycle these waste products. This study aims to determine the influence of crushed oyster shells as partial fine aggregate replacement on the properties of concrete using Type I Ordinary Portland Cement, Type IP Portland-Pozzolan Cement and Type II Moderate Sulphate Resistance Portland Cement.
The fine and coarse aggregates were prepared considering an effective size distribution of 2 mm (No. 10) and 19 mm (3/4 in), 12.7 mm (1/2 in.) and 9.51 mm (3/8 in.), respectively. The oyster shells were cleaned, crushed and sieved with an effective size of 4 mm. The materials used underwent a series of tests to determine its physical properties, namely fineness modulus, relative density (specific gravity), absorption and bulk density (unit weight). The mix designs formulated in this study has a target strength of 20 MPa with varying crushed oyster shells replacement of 0%, 10%, 20% and 30%. The density, compressive strength, split tensile strength and flexural strength were evaluated at 7, 14 and 28 days. Test results showed that the mechanical properties of the concrete developed a directly proportional relationship with curing days and an inversely proportional relationship with the percentage replacement of crushed oyster shells. The highest compressive strength obtained was 25.39 MPa with a 0% crushed oyster shell replacement and a Type IP Portland-Pozzolan Cement with Fly Ash, followed by 22.52 MPa with 0% crushed oyster shell replacement and a Type I Ordinary Portland Cement. Author's Abstract