Consolidation Characteristics of Lateritic Soil Treated With Rice Husk Ash

Abstract

Lateritic soil was treated with 0, 4, 8, 12 and 16% rice husk ash (RHA) by dry weight of soil to determine its consolidation properties. Test carried out include; particle size distribution, specific gravity, compaction test with varying compactive efforts (British Standard Light (BSL), West African Standard (WAS) as well as British Standard Heavy (BSH)) and consolidation test. Samples for consolidation test were compacted and then cured for 7, 28 and 56 days; then subjected to one dimensional consolidation testing to observe the influence of curing period and compactive effort on its consolidation characteristics. Index tests showed improved geotechnical properties. The maximum dry density (MDD) for BSL compaction decreased with a rise in RHA content from 1.72 to 1.42 Mg/m3 while optimum moisture content (OMC) increased from 16.5 to 27.3% with rise in RHA doses from 0 up to 16%. Similar trend was observed for WAS and BSH energies. The Pre-consolidation pressure rise with increment in RHA content and also with increase in both compactive efforts and curing period with few exceptions. At 12% RHA content, the Pre-consolidation pressure increased from 65 to 66.5kN/m2 at 7 days and 56 days respectively. Increase in RHA content caused a decrease in Compression Index (Cc) and Swelling Index (Cs). Compression Index also decreased with increase in both compactive efforts and curing period. There was no observed trend in the Swell Index with curing period. As the compactive efforts increased, the swell index decreased. The RHA reduced the Coefficient of Volume Compressibility (Mv) and the Coefficient of Consolidation (Cc). Curing period and compactive effort have no effect on Mv and Cc. Based on the results obtained, curing period of atleast 28 days using up to 12% RHA compacted at energy level of BSH improved the properties of the treated soil and can be use for geotechnical engineering applications like embankment or rural roads.

Stabilization of Lateritic Soil for Road Application Using Lime and Cow Bone Ash

“…They are referred to as soil type as well as rock type. Laterites are formed from the leaching of parent sedimentary rocks, metamorphic rocks and igneous rocks which leaves the more insoluble ions of mainly iron and aluminium, although some investigators prefer to define laterite as a rock or part of a soil" [12]. "Lateritic soil develops by intensive and delayed weathering of the fundamental parent rock leading to tropical weathering (laterization) which is a delayed process of chemical weathering that creates a great variety in the thickness, grade, chemistry and ore mineralogy of the subsequent soils.…”

Enhancement of Engineering Properties of Black Cotton Soil Using rice husk and sawdust ash

“…To address this issue, researchers have investigated various ways to enhance the physical properties black cotton soil, using waste materials such as fly ash, rice husk ash, sawdust ash, etc, to ensure that it can provide adequate support for the structure being built on it. [5]. These waste materials are by-products of various industrial processes and are considered environmentally hazardous if not properly disposed of.…”