Analisis Panjang Polypropelyene Fiber Hasil Modifikasi Strapping Band Terhadap Kuat Tekan dan Kuat Tarik Belah Beton Normal

Waste plastic in the form of polypropylene strapping band was utilized as an additional material in normal concrete to enhance its mechanical performance while reducing environmental impacts caused by plastic waste. This study aims to investigate the effect of polypropylene strapping band fiber length variation on the compressive strength and splitting tensile strength of normal concrete. The concrete was designed with a target compressive strength of 20 MPa at 28 days, incorporating polypropylene fibers at a constant dosage of 3.33% of the cylindrical specimen volume. Fiber length variations of 20 mm, 25 mm, and 30 mm were examined. Compressive strength and splitting tensile strength tests were conducted at concrete ages of 21 and 28 days. The results indicate that normal concrete achieved average compressive strengths of 18.27 MPa and 20.20 MPa, with splitting tensile strengths of 1.40 MPa and 1.70 MPa at 21 and 28 days, respectively. Concrete containing 20 mm fibers exhibited the most significant improvement, reaching compressive strengths of 19.67 MPa and 22.40 MPa and splitting tensile strengths of 1.80 MPa and 1.90 MPa at 21 and 28 days. The 25 mm fiber variation provided limited enhancement, while the 30 mm fibers tended to reduce strength due to decreased workability and less effective compaction. These findings demonstrate that fiber length is a critical parameter in fiber-reinforced concrete, and at a fiber content of 3.33% by volume, a fiber length of 20 mm yields the most optimal mechanical performance in normal concrete.