Experimental research

Includes bibliographical references

Concrete pavement construction relies heavily on conventional aggregates, while the continuous generation of agricultural waste creates a need for more sustainable construction materials. Coconut husk fiber, an abundant agricultural by-product in the Philippines, was investigated as a potential partial replacement for coarse aggregates in concrete pavement. This study aimed to determine the effects of varying percentages of coconut husk fiber on the compressive strength, workability, and density of concrete and to identify the most suitable proportion for pavement applications in Barangay Luciano, Trece Martires City, Cavite. An experimental research design was employed using 5 concrete mixtures consisting of a control mix with 0% coconut husk fiber and 4 experimental mixes containing 0.3%, 0.6%, 0.9%, and 1.1% coconut husk fiber by weight of gravel. Concrete cylindrical specimens measuring 4 inches 8 inches were prepared, cured for 7 days, and subjected to compressive strength testing following the American Society for Testing and Materials C39 standard. Slump tests were conducted to evaluate workability, while hardened density was determined to assess the physical characteristics of the concrete mixtures. The results showed that the 0.3% coconut husk fiber mixture obtained the highest 7-day average compressive strength of 14.49 megapascals or approximately 2,100 pounds per square inch, exceeding the study's target strength of approximately 12 megapascals or 1,700 pounds per square inch. In contrast, compressive strength decreased as the fiber content increased to 0.6%, 0.9%, and 1.1%, which was associated with reduced workability, fiber clumping, and increased voids within the concrete mixture. The addition of coconut husk fiber also generally reduced workability and hardened density, although the 0.3% mixture maintained a density close to the standard density of 2,400 kilograms per cubic meter. Overall, the study identified 0.3% coconut husk fiber as the most suitable proportion among the tested mixtures, providing the best balance of compressive strength, workability, density, and overall concrete performance. The findings indicated that controlled utilization of coconut husk fiber could provide a sustainable alternative material for concrete pavement while contributing to agricultural waste reduction and resource-efficient construction practices.