NATURAL AND STABILISED PROPERTIES OF SURALAYA POWER STATION PULVERISED FUEL ASHES.

• Main Author: MULYOWIHARJO RAB, SUTARTO
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/2742
• Institution: Institut Teknologi Bandung

Pulverised Fuel Ash (PFA} is a by-product from the burning of coal at electricity power stations. At Suralaya in West Java, PFA is being stockpiled from the residue of. two types of coal being supplied to the boilers, one from Bukitasam in South Sumatra and one from Blair Atholl Coal Field in the Hunter Valley, New South Wales, Australia.The engineering characteristics of the two PFA's have been found to be significantly different, as well as results obtained when mixing the PFA's with varying amounts of lime, or soil, or a combination of lime and soil. Higher strengths and greater pozzolanic activity were noted in the PFA from the Australian source, with very little pozzolanic activity evident in the Bukitasam material. Neither PFA exhibited any inherent undrained strength on soaking, in line with that of silty soil, PFA having a similar grading fraction. Use'as embankment fill without stabilisation with lime would indicate very difficult construction problems in terms of compaction or protection agains trainfall. The introduction of commercially accep table quantities of lime would facilitate construction and allow embankments to be built satisfactorily. Mixtures of Lime/PFA, soil/PFA, soil/lime andlime/PFA/soil all showed lossesin unconfined compressive strength on soaking, in the order of 55 %. The introduction of soil was found to serve just as a bulk fill, but would make handling of the PFA simpler. The commercial viability of this has not been examined, and a full range of tests on mixtures of the three materials not carried out.Adequate strengths for subbase could be obtained with lime/Australian PFA mixtures but, even with high quantities of lime, the stabilised lime/PFA/soil mixes were not found to be sufficiently strong for such a consideration. <br />