Investigasi Terhadap Komposit yang Terbentuk dari Crumb Rubber-ECC dengan Kerikil-Aspal Porus Berbasis Styrofoam dan Crumb Rubber Berdasarkan Uji Tekan dan Lentur

Abstract

CR-ECC is a composite material consisting of cement, sand, water, superplasticizer, crumb rubber, and cementitious materials, without the use of coarse aggregate. To support the use of environmentally friendly materials, this study utilized waste-based cementitious materials such as fly ash and palm shell ash (PSA). This research was conducted experimentally to evaluate the compressive and flexural strength of asphalt gravel composite using CR-ECC as grouting material. The CR-ECC mix design was derived from mortar ECC with the addition of fly ash and PSA at 0–15% of the cement weight, with 5% intervals. Each variation consisted of three cube specimens measuring 15×15×15 cm and was tested for compressive strength at 3 days of age. The variation with the highest compressive strength was further modified with the addition of crumb rubber (CR) at 0–12.5% with 2.5% intervals, and tested at 3 and 7 days of age. The optimum CR-ECC composition was then used as a grouting material for four types of asphalt gravel composites: pure asphalt, styrofoam-asphalt, crumb rubber–asphalt, and a combination of styrofoam and crumb rubber asphalt. Each variation was tested for compressive and flexural strength at the ages of 3 and 7 days. Compressive strength specimens were in cube form (15×15×15 cm), while flexural strength specimens were in beam form (15×15×60 cm). The results showed that the highest compressive strength was obtained in the crumb rubber asphalt composite variation, with values of 5.92 MPa at 3 days and 6.69 MPa at 7 days. The flexural strength test showed that the pure asphalt gravel composite achieved the highest results, with values of 1.64 MPa at 3 days and 2.72 MPa at 7 days.