PEMANFAATAN ABU TERBANG (FLY ASH) BATU BARA SEBAGAI BAHAN CAMPURAN KONSTRUKSI PERKERASAN JALAN

Abstract

Fly ash is a waste material from a coal processing.  One alternative way of disposal, is used as material component of pavement mixtures. This paper discusses about various proportion of fly ash in order to fulfill the requirement of sub-grade stabilization and ATB mixtures. The study showed that 25% fly ash while mixed with high placidly clay yields lower Liquid Limits (LL) decreased from 100% to 80%, while PI decreased from 65% to 45%. PI increment of bearing capacity increased from 2 kg/cm² to 6 kg/cm² with 28 days curing period. In fact, the result was 10% still can not comply of the Bina Marga requirements while PI = 45%. Coal fly ash can fulfill as filler of ATB, since it is a non-plastic, major proportion (95%) passes No. 200 sieve, inorganic, and dry condition.  After mixing with other ATB materials with filler proportion of 3%-7%, it can comply with stability, flow and air voids requirements.  The study showed that 6% coal fly ash yields lowest air void, and still fulfills the range of filler proportion requirements between 4,5 % and 7%.