Electronic Theses and Dissertation

Peningkatan jumlah limbah plastik low density polyethylene (LDPE) mendorong pemanfaatannya sebagai bahan baku paving block untuk mengurangi pencemaran lingkungan. Penelitian ini bertujuan untuk mengetahui pengaruh rasio plastik LDPE dan pasir terhadap kualitas paving block serta menentukan rasio terbaik yang memenuhi SNI 03-0691-1996. Penelitian ini menggunakan rasio plastik dan pasir 100 : 0, 80 : 20, 60 : 40, 50 : 50, dan 40 : 60. Karakterisasi plastik dilakukan menggunakan FTIR dan analisis termal (DSC, TG, DTG), sedangkan paving block diuji kuat tekan, daya serap air, porositas, densitas dan SEM. Hasil analisis FTIR menunjukkan bahwa plastik LDPE yang digunakan tersusun dari gugus metilena (CH₂). Analisa termal menunjukkan titik leleh LDPE pada suhu puncak 128 °C, degradasi termal utama terjadi di atas suhu 336 °C sehingga proses peleburan plastik dan pencetakan dilakukan pada rentang 180-250°C. Pengujian paving block menunjukkan bahwa rasio LDPE dan pasir berpengaruh nyata terhadap kuat tekan, daya serap air dan densitas. Rasio LDPE pasir 60 : 40 menghasilkan karakteristik terbaik dengan kuat tekan 24,88 MPa, daya serap air 0,39%, porositas 0,52% dan densitas 1,31 gram/cm³ yang termasuk dalam mutu B berdasarkan SNI 03-0691-1996. Hasil pengamatan SEM menunjukkan struktur morfologi rasio plastik pasir 60 : 40 lebih padat dibandingkan sampel 100 : 0.
Kata Kunci: LDPE, pasir, paving block, kuat tekan, daya serap air

The increasing amount of low density polyethylene (LDPE) plastic waste encourages its use as a raw material for paving blocks to reduce environmental pollution. This study aims to determine the effect of the ratio of LDPE plastic and sand on the quality of paving blocks and determine the best ratio that meets SNI 03-0691-1996. This study used a plastic and sand ratio of 100: 0, 80: 20, 60: 40, 50: 50, and 40: 60. Plastic characterization was carried out using FTIR and thermal analysis (DSC, TG, DTG), while paving blocks were tested for compressive strength, water absorption, porosity, density and SEM. The results of the FTIR analysis showed that the LDPE plastic used was composed of methylene groups (CH₂). Thermal analysis showed that the melting point of LDPE was at a peak temperature of 128 °C, the main thermal degradation occurred above 336 °C so that the plastic melting and molding process was carried out in the range of 180-250°C. Paving block testing shows that the ratio of LDPE and sand significantly affects the compressive strength, water absorption and density. The LDPE sand ratio of 60:40 produces the best characteristics with a compressive strength of 24.88 MPa, water absorption of 0.39%, porosity of 0.52% and a density of 1.31 grams/cm³ which is included in quality B based on SNI 03-0691-1996. The results of SEM observations show that the morphological structure of the 60:40 plastic to sand ratio was denser than the 100:0 sample. Keywords: LDPE, sand, paving block, compressive strength, water absorption