Evaluation of Mechanical Properties of High-Strength Reinforced Concrete (HSRC) Beam Containing Periwinkle Shell Ash (PSA)

Abstract

This study evaluated the effects of Periwinkle Shell Ash (PSA) on high-strength reinforced concrete (HSRC) beams. The periwinkle shells were obtained as agricultural waste, ground into fine powder, and charred at a controlled temperature of 500ºC. Laboratory and experimental investigations were carried out on the PSA, and its effect on high-strength concrete (HSC) was assessed within 0% to 15% replacement levels (at 5% intervals) using 64 cube samples and 16 beam samples. Engineering properties such as compressive strength, water absorption, slump, and flexural strength were examined on concrete containing 0% to 15% PSA.

Results show that PSA has a specific gravity of 2.49, with major chemical constituents (SiO₂, Al₂O₃, Fe₂O₃, CaO, MgO, K₂O, Na₂O, P₂O₅, TiO₂, and LOI) responsible for pozzolanic reactions during hydration. The compressive strength results for 0% to 5% PSA replacement fall within the range of high-strength concrete (51.22 N/mm² to 40.11 N/mm²), while 10% to 15% PSA replacement produced conventional concrete strength values (35.78 N/mm² to 34.89 N/mm²). Slump test results indicated a decrease in workability as PSA content increased, while water absorption increased with higher PSA percentages.

The flexural test revealed that as PSA replacement increased, the applied load carried by the beam decreased: 151.75 kN, 137 kN, 122 kN, and 99.75 kN for increasing PSA percentages, with reductions in applied load ranging from 9.72% to 34.27%. Based on the compressive and flexural strength results, a 5% PSA replacement level is recommended for producing high-strength concrete, while 10% to 15% replacement should be used only for conventional concrete. The study also recommends that the government establish an appropriate legislative framework to support the use of PSA as an alternative material in concrete production for the construction industry.