Pengaruh Variasi Panjang Serat Strapping Band Polypropylene Terhadap Kuat Tekan dan Kuat Tarik Belah Beton Usia Dini

Concrete is widely used as a construction material due to its combination of strength, durability, and ease of application in construction practices. At early curing ages, the mechanical properties of concrete, particularly compressive strength and splitting tensile strength, play an important role in determining structural performance and resistance to early-age cracking. This study aims to evaluate the effect of incorporating 3.33% polypropylene fibers derived from strapping band waste on the mechanical properties of early-age concrete. The research methodology began with the examination of concrete constituent materials in accordance with SNI and ASTM standards, followed by compressive strength and splitting tensile strength tests conducted at curing ages of 3 and 7 days. Fiber length variations consisted of 0 mm as control concrete and 20 mm, 25 mm, and 30 mm as fiber-reinforced mixtures. The results indicated that normal concrete without fibers achieved average compressive strengths of 8.07 MPa at 3 days and 13.17 MPa at 7 days, with corresponding splitting tensile strengths of 0.87 MPa and 1.03 MPa. The addition of 20 mm fibers produced the most optimal mechanical performance, resulting in compressive strengths of 12.33 MPa and 15.33 MPa at 3 and 7 days, respectively, along with splitting tensile strengths of 1.27 MPa and 1.40 MPa. In contrast, the use of 25 mm and 30 mm fibers showed a tendency to reduce concrete performance. The findings demonstrate that the utilization of 3.33% strapping band waste as polypropylene fiber has the potential to improve the mechanical properties of early-age concrete while supporting the development of more sustainable and environmentally friendly construction materials.