Characteristics of Compacted Fly Ash as a Transitional Soil

Abstract

Cohesive and non-cohesive soils show a number of properties typical of a given category. Cohesive soils are characterized by cohesion, and the properties of compacted soils closely depend on moisture at compaction. However, many researchers have found the existence of so-called mixed or transitional soils. Compacted transitional soils, macroscopically recognized as non-cohesive, are characterized by mechanical properties and hydraulic conductivity which are strictly dependent on the moisture content at compaction. The aim of this work is to show the influence of the content of fine particles in fly ash on the variation of California Bearing Ratio (CBR) values as a parameter strictly dependent on initial compaction. The CBR values were interpreted in terms of moisture at compaction, void ratio and intergranular void ratio. Three different research samples were selected with fine contents of 45%, 55% and 70%; all samples corresponded in terms of grading with sandy silt. Fly ash containing only non-plastic fines behaved as cohesive soils despite the lack of plasticity. The CBR values decreased with increasing moisture at compaction or void ratio. The CBR values, plotted as a function of the intergranular void ratio, have lower penetration resistance together with fine content.

Effect of Ureolytic Bacteria on Compressibility of the Soils with Variable Gradation

“…1, in accordance with EN ISO 14688-1 standard, the tested non-cohesive soil is fine sand (FSa), and the tested cohesive soil is silt (Si). Class F fly ash (FA) has a grain size corresponding to that of sandy silt (saSi), and in the literature, fly ash is called transitional soil [41].…”

“…In the literature [12,13,19,46,47], in most cases, sandy soils are used to conduct the MICP process, where the bacterial and cementation solution with the use of a peristaltic pump or other equipment, can easily flow through the soil particles. Mitchell & Santamarina [41] prepared a graph showing the bacteria size and types of soils, where the process of biomineralization may be a misguided soil improvement method. However, since then, few studies [48,49], have tested the effect of MICP on fine-grained materials.…”

Determination of Relative Density and Degree of Saturation in Mineral Soils Based on In Situ Tests

“…Among numerous available methods, dynamic probing tests (DP), cone penetration tests (CPT), and dilatometer Marchetti tests (DMT) are commonly applied in leading research centers. In order to reduce the necessity to use various types of equipment, methods of field research are being sought for to enable the interpretation of the obtained results in a wide range [1][2][3][4][5]. One of the field tests that meets this requirement is the Marchetti dilatometer test [6], whose use in the world is significantly increasing.…”

Utilization of Fluidized Bed Combustion Fly Ash in the Design of Reuse Clay Soil in the Form of Self-Compacting Grouts

“…In today's practice there are many technologies available for soil modification or treatment [9][10][11]. In this paper, the method of improving the properties of clay soils focused on is chemical stabilization by FBCA and their subsequent liquefaction.Chemical stabilization aims to modify the soil moisture and, above all, to improve its strength, which increases the soil's softening resistance [12][13][14][15][16][17]. The amount and type of FBCA added should in fact be consistent with the clay mineral content of the soil [11,[18][19][20][21][22].…”