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Consistency of Fine-Grained Soils
Published in Alan J. Lutenegger, Laboratory Manual for Geotechnical Characterization of Fine-Grained Soils, 2023
Soils will behave differently depending on both the absolute values of the Liquid, Plastic and Shrinkage Limits and on the relative difference between these values. The Atterberg Limits can be used to indicate relative soil stiffness in a general way by locating the natural Water Content of the soil relative to the positions of the Liquid and Plastic Limits, as shown in Figure 12.1. For example, if the Water Content of a soil is near the Liquid Limit, we may expect soft soil; if the Water Content is near the Plastic Limit, we may expect stiff soil; and if the Water Content is near the Shrinkage Limit, we may expect very stiff or hard soil.
Phase relationships and soil classification
Published in Burt G. Look, Earthworks, 2023
Atterberg limits are used to determine the plasticity of soil. Highly plastic soils are more sensitive to moisture changes. Both strength and volume changes then occur. Atterberg’s definitions are: Liquid limit (LL) – Minimum moisture content at which a soil will flow under its own weight (corresponds to 25 blows in a Casagrande test or 20 mm penetration in a penetrometer test)Plastic limit (PL) – Minimum moisture content at which a 3 mm thread of soil can be rolled by hand without breaking upPlasticity index (PI) – Range of moisture content over which the soil is plastic → PI = LL − PLShrinkage limit (SL) – Seldom tested; this is the moisture content at which a further decrease in moisture does not cause a decrease in volume of the soil: SL ~ LL − 1.25 PILinear Shrinkage (LS) – Minimum moisture content required for a soil to be mouldable; for low plasticity soils (PI < 10%) it is difficult to establish PL and LL with any accuracy; in these instances, estimate PI ~ 2.13 LS to determine LS
Comparison of test methods for soil
Published in Yanrong Li, Handbook of Geotechnical Testing, 2019
The Atterberg limits refer to a set of water content of soil as the soil changes from one consistency state to another. It includes liquid limit, plastic limit and shrinkage limit. Liquid limit is the water content at which the soil changes from flowing state to plastic state. Plastic limit refers to the water content where the soil transfers from plastic state to semi-solid state, and the shrinkage limit is when the soil from semi-solid to solid state. Among them, liquid and plastic limits can be used for classification of fine-grained soil. Commonly used methods for determining the Atterberg limits include cone penetrometer method, Casagrande method, rolling method and shrinking method (Table 9.19). GB uses a cone with the weight of 76 g while BS uses a cone of 80 g. Correspondingly, the penetration depth indicating the liquid limit in these two standards are 17 mm and 20 mm, respectively. See Table 9.20 for a detailed comparison. Casagrande method is to place the sample on the disc where the sample is notched into two halves. The disc falls at a certain rate to hit the bottom plate, so that the two halves of the specimens are folded to a length of 13 mm with 25 hits. The water content satisfying this situation is the liquid limit. Casagrande method is included in GB, ASTM and BS. The difference between these standards is hitting number required to determine the liquid limit. BS requires that the hitting numbers in two successive tests is the same. ASTM requires that the difference of the hitting number in two successive tests shall not exceed 2. GB has no requirement in this regard (Table 9.22).
The effect of polymer materials on the stabilization of forest road subgrade
Published in International Journal of Forest Engineering, 2021
Fatemeh Mousavi, Mohammad Avatefi Hemmat, Ehsan Abdi, Amirhossein Norouzi
Since most of the forest roads in the study site contain local fine-grained material, soil stabilization can increase the long-term strength of the road network. However in areas that retain saturated soils, another objective of soil stabilization is to decrease the plasticity features of soil which are measured by Atterberg limits (Shirsavkar and Koranne 2010) and swelling tests. Atterberg limits, especially the liquid limit (LL) and plastic limit (PL), are the most important water-related properties that are considered in the classification of adhesive soils. They are indicators to define and to predict the mechanical properties of fine-grained soils (Kayabali et al. 2015). Atterberg limits are widely used individually or with other soil properties to either predict engineering behaviors such as compressibility, permeability, swelling, and contraction, or to choose a proper soil stabilization method (Carter and Bentley 2016). As the forest environment often includes saturated soils, considering their swelling potential and Atterberg limits is very common in forest engineering operations. In this research, two polymer agents of CBR Plus and RPP were applied to stabilize a high-plasticity clay forest soil (CH) with effective results. In agreement with previous studies (Moayed and Allahyari 2012; Mousavi and Karamvand 2017), the plastic limits (LL, PL and PI) of the forest soil sample were improved.
Influence of soil type on strength and microstructure of carbonated reactive magnesia-treated soil
Published in European Journal of Environmental and Civil Engineering, 2020
Song-Yu Liu, Guang-Hua Cai, Jing-Jing Cao, Fei Wang
The previous studies on the carbonation/stabilisation of reactive MgO-treated soils were mainly aimed at low plastic soils including sharp sand, model soils with a slightly clayey silty sand and an organic clayey silt, as well as a low plastic silt (Cai et al., 2015a, 2015b; Yi et al., 2013a, 2013b). However, there was scarce information in the geotechnical literature regarding the influence of soil types on engineering behaviours of carbonated reactive MgO-treated soils. In addition, Mitchell and Soga (2005) deemed that Atterberg limits were extensively used for identification, description, classification and mechanical preliminary assessment of soils. Atterberg limits include liquid limit (wL), plastic limit and plasticity index, in which liquid limit influenced by clayey particle content has been considered as an important property index to characterise soil type, as well as to estimate the engineering properties such as plasticity, water holding capacity, compressibility and strength; and liquid limit has a better correlation with strength (Burland, 1990; Du, Fan, Liu, Reddy, & Jin, 2015; Fan, Du, Reddy, Liu, & Yang, 2014; Mitchell & Soga, 2005).
Stabilization of lateritic soil from Agbara Nigeria with ceramic waste dust
Published in Cogent Engineering, 2019
Olumuyiwa Onakunle, David O. Omole, Adebanji S. Ogbiye
Atterberg limits, consisting of liquid limits, plastic limits, and shrinkage limit, measures the unique characteristics of soils concerning water content. Different soils demonstrate different behaviors at different moisture content levels, and these behaviors may be desirable or not, depending on the context of use. Figure 4–6 illustrate a detailed graphical arrangement for different percentages of Ceramic Dust at intervals of 5, 10, 15, 20, 25 and 30% (by weight) in the obtained soil sample. From Figure 4, it is evident that the increasing amount of Ceramic Dust caused a progressive reduction in the Plastic limit values from 40.11% (unmixed soil) to 23.31% (when mixed with 30% Ceramic Waste Dust). A decrease in Liquid Limit values was also observed with the addition of ceramic dust. These reductions are attributed to the presence of calcium oxide (CaO) in the ceramic waste dust, which reacts with water particles in the lateritic soil, thereby lowering its moisture content. In the process, forming mortar (Ca(OH)2), which is a sturdy material. Figure 5 shows the reduction in Liquid Limit values from 59.62% (for unmixed soil sample) to a significantly decreased value of 35.61% (when blended with 30% Ceramic Waste Dust), with a coefficient of determination of 0.94.