Peat Stabilization using Gypsum and Fly Ash

Abstract

This paper presents the stabilization of local peat soil from Matang, Sarawak, using gypsum and fly ash. Peat soil has been identified as one of the major groups of soils found in Malaysia, which has high compressibility and low shear strength. Presence of soft or peaty soil is a major problem encountered by civil engineers in Sarawak. Different percentages of gypsum (i.e., 2, 4, 6 and 8%) and fly ash (i.e., 5, 10, 15, 20 and 25%) were added into peat soil at optimum moisture content and it’s maximum dry density determined by standard Proctor test. Unconfined compressive strength (UCS) test were conducted to determine the strength gain after 7, 14 and 28 days of curing periods. Physical properties of the peat soil have also been studied for identification and classification purposes. The unconfined compressive strength test results show that the peat soil gained strength due to the addition of different percentages of admixtures such as gypsum and fly ash and the strength also increases with the increase of curing periods.