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The properties of residual soils, according to literature, are sensitive to the pre-test drying method given to the sample prior to testing. Similarly, residual soils such as laterites/lateritic soils are formed under various climatic conditions; hence, they show different degrees of sensitivity to the pretest drying method. This work is therefore carried out to elucidate the influence of the pre-test drying temperature or method on the properties of three lateritic soils that developed over three different Pre-Cambrian basement complex rocks from Ado-Ekiti, SW, Nigeria. The soils were subjected to two pre-test drying temperatures before conducting laboratory tests. The pre-test drying temperatures considered in this study include air-drying, oven-drying at 60 °C, and oven-drying at 110 °C. Pre-test drying at 60° and 110 °C caused particle aggregation (which reduced the soil surface area) and loss of cohesion. Consequently, this reduced the specific gravity, optimum moisture content, clay content, consistency limits, and unconfined compressive strength of the lateritic soils. The maximum dry density and sand content increased as the pre-test drying temperature increased. The pre-test drying temperature did not significantly change the plasticity classification of the soils; however, at higher pre-test temperatures, the soils become less plastic. The free swell index of the lateritic soils increased with increasing pre-test drying temperatures (up to 60 °C) before decreasing when the temperature rose to 110 °C. This study has revealed the effect that pre-test drying temperatures may have on the properties of lateritic soils, and these may produce soil properties that do not likely indicate the actual field performance of the tested soils. [ABSTRACT FROM AUTHOR]

Sedimentary Rocks composing the Thar Lignite basin Pakistan are of clastic origin. These rocks have comparatively low uniaxial compressive strength (UCS) values, and hence recognized as ‘soft sedimentary rocks’ in this study. UCS is a fundamental property of rocks, used by mine design engineers in designing the surface and underground excavations. The purpose of this study is to investigate the relationship between UCS with Brazilian tensile strength (BTS), and index properties of soft sedimentary rock formations at Thar Lignite basin. Various correlations between mechanical and physical properties of rocks have been developed previously. However, no significant correlation has been developed on UCS with BTS and index properties for soft sedimentary rocks. Numerous Rock samples from Two complete geotechnical drillholes at Block-IX Thar Coalfield were selected. Standard test procedures were implemented to determine the UCS, indirect Tensile and index properties such as point load strength, and shore Scleroscope hardness. The correlations between rock properties were established using simple and multiple regression techniques, and empirical equations were obtained. These equations can be used to predict the UCS and tensile strength of soft sedimentary rocks by performing simple index tests; which are quick, economical, and easier to be performed on the site. [ABSTRACT FROM AUTHOR]

In this study, the effects of a water soluble acrylamide polymer solution (PS) treatment on the index properties, compacted properties, free swelling, stress–strain relationship and compressive strength of an expansive CH soil obtained from the field in Houston, Texas was investigated. In order to characterize the clay before and after polymer treatment X-ray diffraction analyses and Thermogravimetric analyses were used respectively. In addition to characterizing the behavior of expansive CH soil (free swelling of 15%), the effect of treating the soil with a acrylamide PS was investigated and the performance was compared to 6% lime treated soil cured for 7 days at 25 °C and 100% relative humidity before testing. In treating the soil, PS content was varied up to 20% (by dry soil weight) using three different mixes (polymer content) and the soil samples were cured for 1 day at 25 °C and 100% relative humidity before testing. When the CH soil was treated with 10% PS, the liquid limit (LL) and plasticity index (PI) (index properties) of the expansive soil decreased by 33% and 57% respectively. The free swelling of the expansive soil decreased by 60% and the compacted (ASTM 698 standard method) compressive strength increased from 126 to 496 kPa. Polymer treatment also increased the compacted maximum dry density and reduced the optimum moisture content of the treated CH soil. The behavior of the LL, PI and swelling of the expansive soil treated with different percentages of the PSs have been quantified using the Vipulanandan property correlation model. Compressive stress–strain relationships of the expansive soil treated separately with lime and PS have been modelled using the nonlinear Vipulanandan p–q stress–strain model. The stress–strain model parameters were sensitive to the polymer content and the type of treatment. [ABSTRACT FROM AUTHOR]

The utilization of industrial byproducts in landfill liners has shown increasing interest and continuous awareness in meeting their regulatory standards (i.e. 1 × 10−7 cm/s, as per the United States Environmental Protection Agency) and often proved to be suitable as a liner material. This paper reviews the use and application of two largely produced industrial byproducts namely, thermal power stations (i.e. fly ash and bottom ash) and iron-steel industries (i.e. steel slag and blast furnace slag) as a liner in a landfill. A detailed and critical review of these byproducts with their experimental data on geotechnical properties such as index properties, compaction characteristics, compressive strength and hydraulic conductivity were presented. The aim of this paper is to provide geotechnical correlations on hydraulic conductivity with index properties, compaction characteristics and compressive strength of various industrial byproducts with soil types and additives were discussed. The presented correlations between hydraulic conductivity and other engineering properties will be helpful in determining the design parameters for landfill liner. From the set of resulted correlations, optimum percentage binders for each industrial byproduct are highlighted. Overall, these geotechnical correlations prove to be innovative which were obtained from experimental data will serve as a benchmark to validate the experimental results for various upcoming research works. Image 1 • Briefly reviewed on thermal and iron-steel industrial byproducts as a landfill liner. • Described the effectiveness of industrial byproducts on various soil mixtures. • Correlated index properties, compaction and strength with hydraulic conductivity. • From the correlated data, prediction of optimum percentage binders is highlighted. • Proposed datasets serves as benchmark and validate the upcoming research works. [ABSTRACT FROM AUTHOR]