What is a soil test in construction?
Soil testing is a very important part of building and road construction. Thus, the purpose of soil testing for construction is to determine the suitability of the soil for the type of construction to be done. The test is also done to determine the presence of groundwater.
How do you do a soil test for construction?
In this method by excavation a hole is created and the soil dry density to be measured with it. The hole is filled with uniform sand of known dry density. Dividing the mass of sand poured into the hole with dry density of sand gives the volume of hole.
What soil test is required for building construction?
The most commonly used compaction test is Proctor’s test, determines the compaction characteristics of soil reducing air voids by densification. This test gives information about maximum dry density and optimum water content of compacted soil. These are some of the frequently used soil tests for any structure.
Why is soil testing necessary before construction?
The soil testing before construction is first step and important step for many reputed construction companies. This rate determines the rate of the structure stabilization on the soil. The soil testing also determines the length and depth of the pillars put in the soil to lay the foundation of the building.
What is a boring test?
Boring test refers to a geological test applied to the soil in order to understand the lithology of the ground and determine how much weight that soil can take with or without the aid of any additional footings, piers or other support structures and what sort of materials are the best for these structures involved on …
What is Atterberg limit test?
Atterberg limits is a basic measure of the critical water content of fine-grained soils. These tests include shrinkage limit, plastic limit, and liquid limit, which are outlined in ASTM D4318. Depending on the water content of a soil, it may appear in four states: solid, semi-solid, plastic and liquid.
What is a good liquid limit?
9.2. 1 Consistency and Plasticity
| Soil | Liquid limit wL (%) | Plastic limit wp (%) |
|---|---|---|
| Silt, low plasticity | 25–35 | 20–28 |
| Silt, medium plasticity | 35–50 | 22–23 |
| Clay, low plasticity | 25–35 | 15–22 |
| Clay, medium plasticity | 40–50 | 18–25 |
How are Atterberg limits calculated?
Is determined by subtracting the Plastic limit from the natural water content of the sample, then dividing by the plasticity index. Soils with a LI of 1 or more will be closer to the liquid state. A LI of 0 or lower indicates soils that are harder and more brittle.
What is the plastic limit?
The plastic limit is the water content at which a soil-water paste changes from a semisolid to a plastic consistency as it is rolled into a 3.175-mm (1/8-inch) diameter thread in a standard test.
What is plastic limit test?
Plastic limit test is one of the laboratory tests used internationally to differentiate or classify soils into groups. When the water content or moisture content of soil increases beyond a limit then the soil starts to behave as liquid.
How is plastic limit calculated?
Calculate the plastic limit wp by dividing the “weight of moisture” by the “dry weight of sample” and multiply by 100. Plasticity Index (Ip) of a soil is the numerical difference between its Liquid Limit and its Plastic Limit.
What is the difference between liquid limit and plastic limit called?
The difference between the liquid limit and the plastic limit is known as the plasticity index (IP), and it is in this range of water content that the soil has a plastic consistency. The consistency of most soils in the field will be plastic or semi-solid.
What are Atterberg limits used for?
In the field, the Atterberg Limits, can be used as a guide indicating how much a soil is likely to settle or consolidate under load. If the field moisture is near the liquid limit, a lot of settlement is likely. The opposite is true if the field moisture is near or below the plastic limit.
Why is there 25 blows in liquid limit?
Theory: 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 12 mm on being given 25 blows in a standard manner. At this limit, the soil possess low shear strength.
What is a good plasticity index?
Some critical values of the plasticity index for aquaculture To construct a pond dike without a clay core*, the plasticity index of the soil material should have a value between 8 and 20 percent. For best compaction, the PI should be as close to 16 percent as possible (see Section 10.3).
What is soil plasticity index?
1. DEFINITION. 1.1 The plasticity index of a soil is the numerical difference between its liquid limit and its plastic limit, and is a dimensionless number. Both the liquid and plastic limits are moisture contents.
Which kind of soil holds the most water?
Clay soil
How do you read plasticity index?
The plasticity index is the size of the range of water contents where the soil exhibits plastic properties. The PI is the difference between the liquid limit and the plastic limit (PI = LL-PL)….Plasticity index
- (0) – Non-plastic.
- (<7) – Slightly plastic.
- (7-17) – Medium plastic.
- (>17) – Highly plastic.
What is a toughness index?
The toughness index is a measure of the shearing strength of the soil at the plastic limit. Sandy soils changes from liquid state to semi-solid rather abruptly. These soil do not passes plasticity and area classified.
What is the purpose of plasticity index?
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. The plasticity index, in combination with water content at liquid limit (wL), indicates how sensitive the soil is to the changes in moisture content.