![]() ![]() (6.Soils intended to support structures, pavements, or other loads must be evaluated by geotechnical engineers to predict their behavior under applied forces and variable moisture conditions. This result can be generalized somewhat by noting that when R ˙ / c 0 > 0.1 Eq. Compressibility of the water becomes important, however, for bubble wall Mach numbers in excess of only 0.1 and at ( P g 0 / P ( r )) as high as 10 −2 atm. Compressibility of the liquid limits this process numerically computed values of R ˙ given by Hickling and Plesset show that ( R ˙ / c 0) theoretically exceeds unity when ( P g 0 / P ( r )) is less than 10 −4 for ambient pressures of 1–10 atm. The rate of increase is less pronounced, however, than this simple theory shows. As P g 0 diminishes to zero, the wall Mach number increases indefinitely. ![]() The relationship shows that the limiting velocity is influenced both by the amount of heat transfer that may occur and by the partial pressure of gas in the cavity. 6.20 for two values of ambient pressure and this figure should be examined in conjunction with Fig. The plastic limit and the plasticity index of steel slag cannot be estimated due to the fact that steel slag is low-plastic in nature.Įq. The liquid limit of steel slag cannot be obtained due to noncohesiveness or reduced cohesiveness of the particles. Both liquid and plastic limits depend upon the amount and type of clay present in soil (IS-2720-Part 5-1995). Sands, gravel, and peat do not posses plasticity and are reported as being nonplastic (wP = 0). The plasticity index, in combination with water content at liquid limit (wL), indicates how sensitive the soil is to the changes in moisture content. The difference between liquid and plastic limits is called the plasticity index, and it represents the range of water content over which the soil is plastic. They can be categorized as very hard, hard, stiff, medium, soft, and very soft. Most clay has a liquid limit of the order of 50%–90% however it can exceed 100%.Ĭonsistency in fine-grained soils means the properties of friability, stickiness, plasticity, and resistance to deformation. If there is continued sliding, report that the liquid limit could not be obtained. In such cases, discard the result and repeat the process until flowing takes place. Soils sometimes tend to slide instead of flowing. In the case of tearing of the sides of groove in Attergberg’s limit apparatus, the groove may be cut in stages. Soil with low clay content has to be tested soon after being mixed thoroughly with water. The potential for swelling can be indicative from high liquid limits coupled with a high plasticity index. For cohesion-less soil, however, the liquid limit is meaningless. The identification and classification of fine-grained soil is done with the help of liquid and plastic limits. At this limit the soil possess low shear strength. The liquid limit is the moisture content at which the groove, formed by a standard tool into the sample of soil taken in the standard cup, closes for 10 mm on being given 25 blows in a standard manner. Bansode, in Characteristics and Uses of Steel Slag in Building Construction, 2016 7.3.1.4 Determination of Atterberg’s limitsĪtterberg’s limits are liquid limit, plastic limit, and plasticity index. ![]() Thus, for samples that are to be tested with a view to utilizing the results for prediction of the viability of electro-osmosis, it is important that the tests are undertaken in accordance with BS 1377: Part 2 ( British Standards Institution, 1990) and not repetitively wetted and dried. If the soil is tested repetitively, the exchangeable cations can be flushed from the clay, and a change in the Atterberg limits takes place. Mg 2+ , Fe 2+ and Al 3+ ) give lower values. Na + and K +) give higher values of liquid and plastic limits whereas the presence of divalent and trivalent cations (e.g. The chemistry of the pore water, which is also reflected in the exchangeable cations present within the clay minerals, influences the range of results for the Atterberg limits presented in Table 5.2. ![]()
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