ABSTRACT

Processing plastic waste into paving blocks is reducing the negative impact of waste on the environment. Plastic as adhesive and sand, fiber as filler in plasbut paving blocks. In previous studies, the highest compressive strength was obtained in paving blocks with a composition of 771.6 grams of plastic, 1800.4 grams of sand, and 11 grams of coconut fiber, with the fiber placed in the middle of the mold. It is expected that in the future this plastic paving block can be used in coastal and beach areas both to support educational tourism on the beach. Therefore, this study was designed to see how the effect of immersion in seawater on the compressive strength of plasbut paving blocks. The plastic used is polypropylene, and the same composition as previous studies and the addition of the variable of soaking time with fresh water and seawater, 3, 5, 7, 9, 11, 13, and 15 days. Soaking with fresh water produces the highest average compressive strength in the 3rd immersion variation with a compressive strength value of 9.78 MPa. Meanwhile, immersion in seawater produces the highest average compressive strength in the 9th immersion variation with a compressive strength value of 13.44 MPa.