Chemical Stabilization of Loess in Northeast Thailand Using the Mixture of Calcined Marble Dust Waste and Sugarcane Bagasse Ash Waste

Abstract

The main objective of this study was to investigate the possibility of utilizing calcined marble dust waste and sugarcane bagasse ash waste as the chemical stabilizer for loess. Loess is widely distributed throughout the northeast area of Thailand. This soil type has a large loss of shear strength and a significant increase in compressibility upon wetting, which are obstructive behaviors for construction materials. The study was divided into two sections. The first section dealt with the study of synthesizing cementitious materials from calcined marble dust waste and sugarcane bagasse ash waste. The second section focused on studying the stabilization of loess. This consisted of observing the effect of stabilizer on the basic properties of soil-stabilizer mixtures and the improvement in its mechanical properties. The additive ratios of stabilizer which were studied were between 0-25 percent by weight. The physical and chemical properties of loess, calcined marble dust waste and sugarcane bagasse ash waste were studied by X-ray diffraction, X-ray fluorescence, thermogravimetric analyzer, differential thermal analysis, laser diffraction particle size analyzer, Brunauer, Emmett and Teller, transmission electron microscope and scanning electron microscope analytical techniques. After analyzing the physical and chemical properties of the stabilizing materials, the sugarcane bagasse ash waste and the marble dust waste which was calcined at 1000 oC for 2 h, mixed with the ratio of 1:1, and then selected as the stabilizer for loess improvement. It was found that the liquid limit and plastic limit of the treated soils had been decreased with the percentage increase of stabilizer. The optimum moisture content tended to increase while the maximum dry density was reduced. This corresponded to an increasing of the stabilizer fraction. By adding stabilizer at 25%, the soaked and unsoaked California bearing-ratio were increased by about 185% and 140%, respectively. Unconfined compressive strength of specimens with 25%...