Formulation and Application of EcoPlast Paving Block Based on LDPE Plastic Waste as Sustainable Construction Material for Pesantren Infrastructure

Indonesia generates an estimated 38.6 million tons of solid waste annually, with Low-Density Polyethylene (LDPE) forming a persistent fraction of plastic debris because it degrades extremely slowly in the environment. This study explores EcoPlast Paving Block, a cement-free paving element manufactured from shredded LDPE waste and natural sand, designed for the practical needs of Islamic boarding school (pesantren) infrastructure. Three LDPE–sand mass ratios (70:30, 50:50, and 40:60) were investigated, each represented by three specimens (n = 9) with nominal dimensions of 20 × 10 × 6 cm. Compressive strength was measured at 28 days, using the procedure of SNI 03-0691-1996 as an equivalent performance reference. The mixes achieved average strengths of 13.40 MPa, 20.54 MPa, and 42.69 MPa for 70:30, 50:50, and 40:60 respectively, indicating a consistent increase in strength with higher sand content and placing the 40:60 composition above the Grade A threshold. Water absorption remained below 3% for all specimens. These results suggest that LDPE–sand paving blocks can offer a lightweight, durable, and waste-based alternative to conventional cement paving in pesantren courtyards and access ways.