5. RELATIVE DENSITY TESTS 5.1.1 OBJECTIVE To determine the relative density of given coarse grained soil 5.1.2 Learning Outcomes Understand the Principle of relative density Maximum, minimum and natural densities and unit weights and methods of determining them (ASTM D 4253 & ASTM D 4254) Perform the tests Calculate relative density of the given soil sample Write a report on the test exercise 5.1.4 Need and Scope Relative density is an arbitrary character of sandy soil deposits. In real sense, relative density expresses the ratio of actual decrease in volume of voids in a sandy soil to the maximum possible decrease in the volume of voids i.e. how far the sand under investigation is capable to further densification beyond its natural state. Relative density and percent compaction are commonly used for evaluating the state of compactness of a given soil mass.
Fig.4. Permeability Meter This sand specimen is placed in the mercury cup of the permeability meter. The air drum is raised to take 2000 cm3 of air in to the air drum which will be indicated by the graduation on it. The whole air is then allowed to escape through the sand specimen with a pressure of about 10 g/cm3 and the time is recorded. The permeability number of the sand sample can be calculated from the following equation: P =V h/A t p (4.1) Where P = AFS standard permeability number V = Volume of air in cm3 = 2000 cm3 h = Height of specimen in cm = 5.08 cm (or, 2 inches) A = Cross sectional area of specimen in cm2 = 20.268 cm2 p = Air pressure in g/cm2 = 10 g/cm2 t = Time in minutes The above equation may be simplified as P =
Study on Behavior of Soil using Gypsum Abstract There are several places in the world particularly middle East Asia and Africa has problem of gypsum contaminated soil known as gypsiferous soil. Gypsiferous soils cover approximately 100 million hectors in the world. Gypsum not only dissolve in presence of water it also changes geotechnical properties of soil. In the current study effect of gypsum on Atterberg limits and compaction character tics of soil was studied. Different percentage of gypsum was added with a soil from Raipur to simulate the conditions of Gypsiferous soil.
The soil was placed in a beaker, added an equal volume of 0.01M CaCl2 and was stirred vigorously for 15 seconds making the mixture thick and uniformly slurry. The sample was set aside for 30 minutes. After, it was briefly stirred to incorporate any water that has separated. Using a pH meter, the measurement was taken by gently swirling the probe in the slurry, making sure that the probe was well immersed in the soil. Three trials were done and the average pH was taken.
Measure the height of clay , silt layer. Calculate the percentage of clay and silt in the total sand layer. Normally clay and silt content in natural sand should not exceed 10 percent by volume. The allowable limits of material passing 75 micron sieve for natural sand and crushed sand specified. Sieve Analysis of sand: Sand consist of material mostly between 4.75 mm and 150 microns sizes.
The value of B is needed to determine whether the soil is saturated or not. When B=1 the soil is saturated and if B<1 the soil is partially saturated. 3. For a soil that has cohesive component to its strength, describe the mode of slope failure and the general approach used to determine the factor of safety for such a
It includes all the solids which can pass through the filter pad of a Gooch Crucible. Industrial discharges, sewage, fertilizers, road runoff, and soil erosion are main sources of total solids. Total solids can be expressed as milligrams per liter (mg/L). Total solid measurements are useful as an indicator of the effect of runoff from construction, sewage treatment plant discharges and other sources. Total solids affect water clarity and will be higher in highly mineralized water, which result in unsuitability for many applications.
Lab Report #3: Laboratory Compaction Characteristics of Soil Using Standard Effort (12,400 ft-lbf/ft3 (600 kN-m/m3)) Soil compaction demonstrates how the soil will behave considering factors such as physical and chemical properties, moisture content, method of compaction, amount of compactive effort, and thickness of layer or “lift” being compacted when a compactive effort was added to it. This results to a compaction curve which is a plot of dry density versus moisture content. This was obtained by compacting moist soil with prescribed added amount of water in a compaction mold and getting the moisture content of a subspecimen retrieved from the center of the compacted mixture. The peak of the curve is a point showing the optimum moisture
4.3.3 Group index To evaluate the quality of a soil as a subgrade material, the Group Index (GI) is also used along with the groups and subgroups of the soil. Group index is a function of the liquid limit, plasticity index, and the amount of material passing the 0.075mm sieve. A group index of 0 indicates a “good” subgrade material and a group index of 20 indicates a poor subgrade material (AASHTO, 2000). Group index is calculated using the following formula. GI = (F-35) [0.2 + 0.005(LL-40)] + 0.01(F-15) (PI-10) Where F= percent of fine passing sieve size 0.075mm LL = Liquid Limit PI = Plastic Index When the group index for soils belonging to groups A-2-6 and A-2-7 is calculated the partial group index for PI should
Fine Aggregate The sand used for this work was locally procured. Sieve Analysis of the sand was carried out in the laboratory as per IS 383-1970. Result conformed that fine aggregate of zone III. The properties of fine aggregate are given in table 2. TABLE 2.