Compressibility behaviour of peat stabilized with low calcium fly ash an experimental study

Abstract

Peat is a kind of soft organic soil having partially disintegrated plant remains hence it is not good for constructions. Chemical stabilization is the commonly used ground improvement technique by adding chemical admixtures such as ordinary Portland cement, fly ash, natural fillers etc. In Sri Lanka, annually 150 metric ton of fly ash is produced in Nuraicholai coal fired power plant and only about 20 % is usable for cement production, leaving huge amount of fly ash ends up in landfills. Thus, our research focused on stabilizing peat using a combination of fly ash and well graded sand. An experimental study was conducted to analyse the stabilization of peat with 125 kg/m3 dosage of well graded sand and fly ash at three various proportions 10, 20 and 30 % by weight. A series of experiments including Unconfined Compressive Strength (UCS) and Rowe cell test were conducted to evaluate the compressibility behaviour of stabilized peat. UCS increases up to 10 % fly ash addition and increases with curing period for all sample types. There is an improvement in settlement behaviour of peat after the stabilization using fly ash and well graded sand.