Testing the soil is required before civil engineers can begin designing any structure for a building, bridge, or dam. There are various types of soil tests for construction projects, each of which provides us with information about the soil’s characteristics.
The soil test determines which types of structures can be built on which types of soil and how much load can be placed on each structure. Each of the different kinds of soil tests for construction perform by Material Testing Laboratory will be discussed in detail in this article.
Moisture Content Test
Generally speaking, the moisture content is defined as the proportion of water to solid particles in a given soil mass divided by the dry weight of solid particles. It is expressed as a percentage of the total.
- The presence of water in the soil and the amount of water present in the soil voids have a significant impact on the engineering behavior of soil. It is one of the most important soil tests for the construction industry. As a result, it is necessary to determine the amount of water present in a soil deposit at a specific location.
Specific Gravity Test
The specific gravity of soil is defined as the ratio of the weight of soil in the air to the weight of an equal volume of water at 4ºC. The specific gravity of soil is measured in kilograms per cubic meter of soil.
- The engineering properties of soil are essential in the design and construction of any structure because they influence how the structure will perform. As a result, it is necessary to determine the engineering properties of the soil under consideration.
- One of the soil’s engineering properties is its specific gravity, measured in kilograms per cubic meter of soil. This tool helps determine the degree of saturation of the soil and the unit weight of moist soil. It is necessary to use unit weights in the soil engineering field when dealing with pressure, settlement, and stability problems.
Dry Density Test
The dry density of soil is defined as the weight of a solid per unit volume of soil mass.
- This types of soil tests for construction is done for:
- Stability analysis
- Determination of bearing capacity
- Determination of degree of compaction
Atterberg Limit Test
In 1911, an agronomist named Atterberg discovered the concept of consistency limits. Consistency limit refers to the minimum amount of water required by soil to transition from one state of consistency to another. As a result, these boundaries are referred to as Atterberg’s limits.
- Liquid Limit (LL). Understanding a soil’s liquid limit is defined as the lowest water content. The soil is still in the liquid state but has a small setting strength against flowing, which can be determined by following a standard procedure.
- Plastic Limit Test (PL). The water content at which soil begins to crumble when rolled into a thread-like structure is approximately 3 mm in diameter. It is also referred to as the soil’s plastic limit or water saturation limit.
- Shrinkage Limit Test. The shrinkage limit is defined as the water content of the soil that will not cause the specimen’s volume to decrease further after the soil’s moisture content has been reduced further. The test for this limit is carried out on a less frequent basis. The ASTM D4943 standard specifies the procedure to be used.
- The consistency limits of the soil are determined by the amount and type of clay present, and they serve as the foundation for the soil classification system. The results of the test have immediate application in the following areas:
- The design of the foundation of the structures
- Predicting the behavior of soils in the fills
- Embankments and pavements
Proctor’s Compaction Test
The proctor compaction test is a simple procedure. The laboratory is carried out to determine the optimal moisture content at which a specific soil type will be the densest and achieve its maximum dry density.
- Compaction tests are performed on soil samples with varying amounts of moisture content to better understand the soils’ compaction characteristics under consideration. The proctor compaction test is one of the necessary soil tests in the construction industry.
California Bearing Test (CBR test)
This test was developed by the California State Highway Department in the United States to evaluate the subgrade strength of highway and airfield pavements in California.
The California bearing ratio value is the load per unit area required to penetrate a soil mass at a specific rate by a standard plunger to the corresponding load per unit area required to penetrate a common material at the same rate.
- It is necessary to conduct this type of soil testing to determine the thickness of flexible pavements following Indian Road Congress specifications.
Consolidation is a process in which the volume of a soil mass is gradually reduced over time due to the expulsion of pore water under sustained loading.
The One-Dimensional Consolidation test is performed in the laboratory and is a type of consolidation test. This test is carried out in a consolidometer, also known as an odometer in some circles.
- The consolidation test is very important in determining the rate and magnitude of settlement in soils and the amount of settlement.
- The consolidation test results are used in the design of the foundation of a structure and the analysis of the soil stability for embankment, footing, and column constructions.
The permeability of the soil is defined as the property of the soil that allows water to pass through it without being absorbed.
- Permeability testing is also an unavoidable part of the soil testing process for construction projects. It is carried out to determine the coefficient of permeability of the soil sample collected.
Soil testing is an essential part of the construction of buildings and roads. No construction project can be started without first ensuring that the soil can withstand the weight of the building.
As a result, the purpose of soil testing for construction is to determine whether or not the soil is suitable for the type of construction that will be carried out. The test is also used to determine whether groundwater is present.