Stabilization characteristics of cemented lateritic soil produced with selected cement types

Laterite soil is widely found in various tropical and subtropical regions. This study focuses on the physical and chemical properties of laterite soil as a precursor for geopolymer synthesis. The characteristics of the soil were determined through experimental analyses, including XRF, XRD, SEM, EDS, FTIR, TGA/DTA, and pH measurements. XRF analysis revealed that the primary chemical oxides are silica, alumina, and iron oxide, which are very essential for geopolymer production. Both XRD and FTIR assessments revealed that the calcination process applied to laterite diminishes its crystallinity while enhancing its amorphous nature, thereby improving its reactivity. TGA and DTA results confirmed significant weight loss and dihydroxylation between 400 °C and 700 °C, while temperatures above 700 °C showed minimal weight loss and no further dihydroxylation. The pH of the tested laterite soil was measured at 5.35, indicating strong acidic behaviour. Based on these combined chemical and physical analyses, this study concludes that laterite soil is a viable precursor material for geopolymer synthesis.

Laterite soil is an embankment soil that is often used because it is easy to find and is widely found in South Kalimantan.However, this land has many shortcomings to be used as embankment soil.This is because the lateritic soil has a clay content and a high Plasticity Index (PI) value.So the quality is still questionable to be used as landfill.To overcome this, it is necessary to improve or stabilize the lateritic soil. In this study, the lateritic soil was stabilized by the addition of slag nickel. This study aims to determine the physical characteristics of laterite soil after being given a mixture of nickel slag addition, this study also aims to determine the effect of the percentage of nickel slag on primary consolidation (Sc) of laterite soil. As well as knowing the effect of the percentage of nickel slag on the parameters of shear strength in the form of cohesion (c) and shear angle (). Consolidation and shear strength specimens were made with 90% of the optimum moisture content. The variations of the nickel slag mixture used in this study were 0%, 5%, 10%, 15%, and 20% of the weight of the soil used. Based on the results of data analysis, the addition of a mixture of nickel slag in each sample variation can reduce the plasticity index value of the lateritic soil. In addition, the addition of nickel slag also affects the value of the primary consolidation settlement value (Sc) of the laterite soil. The addition of the percentage of nickel slag also affects the parameters of the shear strength of the soil, for the cohesion value (c) of the laterite soil experiences a value that decreases with the increase in the percentage of nickel slag. Meanwhile for the shear angle () of the laterite soil, the value increases with the increase in the percentage of nickel slag.

Laterite soil is red soil because it contains iron and aluminum. It is an old type of soil, so it is suitable for all plants. Laterite soils are located in the reservoir area of the Wonogiri Dam - Central Java. The nature of laterite soil that quickly absorbs water and the soil texture is strong and dense indicates the type of soil used for a mixture to make roads. This study aims to identify and characterize the lateritic soils to support the construction of roads that will be used. It is needed to test the soil’s property index, including moisture content test, density test, Atterberg limit, and grain sieve analysis. At the same time, it tested the classification of laterite soil characteristics using standards of USCS and AASHTO. To test the shear strength of the laterite soil is using Direct Shear. Based on the analysis, the laterite soil from sedimentation in Wonogiri dam is classified as poor and does not meet the requirements to be used as a subgrade in building construction. It can be considered include need to improve to carried out first.

Hydraulic and compaction characteristics of leachate-contaminated lateritic soil

Physico-mechanical behavior of self-cementing class C fly ash–clay mixtures

Residual lateritic soils, developed in tropical and similar other climates associated with high temperature and abundant rainfall, are widely used as fill material for various construction activities. The effective use of these soils is often hindered by difficulty in handling them, particularly under moist and wet conditions typical of tropical regions. An attempt has been made to study the plasticity behaviour of a residually derived lateritic soil mixed with a low-calcium fly ash and lime. Three proportions of soil and fly ash were used, with the maximum amount of soil replaced with fly ash limited to 50%. Lime was added in quantities varying from 1% to 8% of the dry weight of soil or soil-fly ash mix. Atterberg limits were determined for the mixes after different curing periods up to 56 days. Owing to the presence of sesquioxides in the residual lateritic soil, unlike other soils, the addition of the low-calcium fly ash caused a decrease in the plastic limit.It was only when lime was also added that the plastic limit of the soil-fly ash mixes was noted to increase, leading to an improvement in workability. Les sols latéritiques résiduels, qui se développent dans des climats tropicaux et autres climats similaires à fortes températures et à précipitations abondantes sont largement utilisés comme matériaux de remblai lors de diverses activités de construction. L'utilisation efficace de ces sols est souvent gênée par un maniement difficile, plus particulièrement dans les conditions humides qui sont typiques des régions tropicales. Nous avons essayé d'étudier le comportement de plasticité d'un sol latéritique résiduel mélangé à de la cendre volante à faible teneur en calcium et à de la chaux. Nous avons utilisé trois proportions de sol et de cendre volante, le volume maximum de sol remplacé par de la cendre volante se limitant à 50%. De la chaux a été ajoutée en quantités représentant de 1 à 8% du poids sec du sol ou du mélange cendre-sol. Nous avons déterminé les limites d'Atterberg des mélanges apre's diverses périodes de durcissement allant jusqu'à 56 jours. En raison de la présence de sesquioxydes dans le sol latéritique résiduel, contrairement aux autres sols, l'adjonction de la cendre volante à faible teneur en calcium a causé une réduction de la limite plastique. Ce n'est que lorsque la chaux a été ajoutée que la limite plastique des mélanges cendre-sol a augmenté, provoquant une amélioration de la maniabilité.

Problem laterite soils are those that do not yield reproducible results using standard laboratory testing procedures. The soils are difficult to evaluate as engineering construction materials. The peculiar problems of these soils have been identified as thermal and mechanical instabilities i.e. the susceptibility to significant changes on the addition of small levels of thermal or mechanical energy.

The Shear Strengths of four laterite soils from Southwestern Nigeria are investigated through: (i) consolidated undrained triaxial compression tests with pore water measurements on Standard Proctor compacted soils and (ii) direct shear tests on remoulded soils.

Microstructure characteristics of cement-stabilized sandy soil using nanosilica

Urbanization is widely assumed to degrade soil ecosystem services, but the changes in the urban soil phosphorus (P) status due to urbanization and the associated environmental implications have rarely been studied. The objective of this study was to investigate the P forms and associated soil properties in urban soils. Thirty sites were selected along an urban–rural gradient in Nanchang, China, to examine the effects of urbanization on soil P fractions. Residual P and NaOH-extractable P (NaOH-Pi and NaOHPo) were the major P forms in the 0–30 cm of urban soils, comprising on average 37% and 43% of the total P pool, respectively, similar to the suburban and rural soils. Compared with non-urban soils, urban soil had higher contents of total P and P fractions (i.e., PH2O, PKCl, NaOH-Pi, PHCl, and residual P), as well as higher contents of related soil P-retentive properties, especially soil pH and Mehlich 3-extractable Ca and Mg. Phosphorus enrichment in the urban soils may become a source of aquatic pollution because the soil labile P content (the sum of PH2O and PKCl) was positively related to total P, PHCl, NaOH-Pi, and residual P, which implied that the labile P can be replenished by these P pools. This study increased the understanding of P stabilization characteristics (e.g., the specific P forms) of urban soils and has further implications for urban environmental management.

Background: Soil fertility is meant for understanding the nutrient requirements, based on fertility status of soils to achieve good crop yields. Soil fertility, compact-ability and erodibility are the domains of soil quality. Among these, the problem of decline in soil fertility compromises maximum productivity. Depletion in soil fertility is the hugest serious due to cropping pattern, leaching, erosion etc., causes loss of considerable amount of nutrients annually. In order to notice information on current soil fertility status, this study was accompanied in different Talukas of Dakhsina Kannada district of coastal Karnataka. Methods: Characterized the soils for fertility status by taking fifty representative samples from each taluk of Dakshina Kannada district in coastal Karnataka to recommend chemical and organic fertilizers applications based on the present soil nutrient status for the farming community. Results: The soils were persisted acidic in reaction, with very low salt content, medium to high in organic carbon status. The available macronutrients of the soil samples indicated that the nitrogen and potassium low to medium in all the Talukas, and low in available phosphorous and Sulphur. Among the DTPA extractable micronutrients, iron and manganese were in high in most samples collected, available copper was adequate and available zinc was also sufficient except in soil samples of Bantwal Taluk. The available boron was found to be low in soils of all the talukas of the district.

Since construction and maintaining a highway is often costly, cost control effectiveness is crucial. While there are number of stabilization techniques, using agricultural waste product, including plastic and eggshell, to stabilize soil is one of the most economical and friendly. The aim of this study was to predict the compressive strength of environmentally friendly lateritic modified with eggshell and plastic powder. For this purpose, muilt condition optimization of plastic and eggshell as stabiilizers via surrigate model was used. Latin hypercube samping was used for pairing generation, and a batching ration of 1:4 with water cement ratio of 0.4 was employed. The results indicated that a significant positive change has been noticed in the engineering characteristics of the clayey soil after adding both of ESP (eggshell powder) and PW (plastic waste). These beneficial changes depend on ESP, PW contents and the curing duration. The curing duration significantly improved the engineering characteristics of the stabilized soil samples. It was established that in all the conditions, the eggshell had a significant influence on the California bearing ratio (CBR), optimum moisture content (OMC) and maximum dry density (MDD). The estimated deviations of the optimized and experimental values were found to be 1.70%, 7.74% and 0.52% for ID number 19 for the CBR, OMC and MDD, respectively. For ID number 58, the deviations were found to be 9.0%, 5.34% and 1.38% for the CBR, OMC and MDD, respectively. In the case of ID number 63, similar deviations were found to be 7.5%, 8.13% and 1.74% for the CBR, OMC and MDD, respectively. From the results, it can be seen that ID number 19 was very close to the optimum value with a deviation of 1.70%, 3.74% and 0.52% for the CBR, OMC, and MDD, respectively, which implies that the optimization process can be said to be realistic. This research enhances the understanding of how ESP and PW influence the engineering properties of lateritic soil.

Numerous ground improvement techniques have been used to stabilize marginal soils to make it more feasible for construction purposes. Soil reinforcement using natural fibres is increasingly preferred as they are sustainable, readily available and inexpensive. This study aims at improving the engineering properties of lateritic soil using the natural coir fibres as reinforcement material. Laboratory tests such as UCS test and direct shear test have been carried out to evaluate the effect of various fibre parameters such as fibre content and fibre length on the engineering properties of soil. Results showed significant improvement in the strength characteristics of lateritic soil after the addition of coir fibres. Optimum fibre parameters that contributed to the enhanced performance of soil were also identified.

The study was conducted during 2015–16 (November 2015-April 2016) at the Bankura district of West Bengal, India to assess the impact of land uses of Bankura on soil properties by sampling and analyzing soils from diverse representative plots from forests, orchards, pastures, cultivated fields, and uncultivated fallow lands that existed over the last decade. The average bulk density was highest at 1.38 g cm-3 in orchard land and lowest at 1.24 g cm-3 in pasture land, and increased with depth. The mean particle density varied from 2.53 g cm-3 in pasture to 2.69 g cm-3 in orchard, and also increased with depth. The total porosity was maximum in orchard (53.97%) and minimum in pasture (45.57%), and varied with depth. Moisture content was greatest in cultivated land (8.98%) and least in pasture (4.23%), whereas mean maximum water holding capacity was greatest in forest land (37.11%) and least in fallow land (29.05%), and both rose with depth. Soil pH was greatest in pasture (6.75) and least in cultivated land (5.61), and electrical conductivity was similarly distributed. Organic carbon content was greatest in forest land (0.41%) and least in cultivated land (0.16%), and decreased with depth. Available nitrogen, phosphorus, and potassium content were greatest in forest land and lowest in cultivated land, and decreased with an increase in soil depth. Pearson's correlation revealed significant correlations between soil properties.

Performance of the cement-stabilized soils primarily depends on the soil type, cement quantity, moulding moisture content and ambient temperature. Control of the moulding moisture content and curing temperature are the challenges for most of the pavement engineers as these play a significant role in the strength development of stabilized soils. In the work presented here, an effort has been made to study the effect of the moulding water content on compressive strength and flexural strength of a stabilized granular lateritic soil collected from the eastern part of India. A detailed experimental programme was conducted, which involves various strength tests such as unconfined compressive strength test, California bearing ratio test and four-point flexure test. Microstructural analysis was also conducted using a scanning electron microscope and X-ray diffraction techniques to study the mechanism behind the variation of strength with varying moisture contents. Effect of moisture was also investigated through measurement of residual compressive strength. It is observed that compressive strength decreases with an increase in the moulding moisture content; however, the flexural strength increases with an increase in moulding moisture content within the testing range of moisture content around optimum moisture content (OMC), i.e. OMC-2% to OMC+2%.