The consistency of the soil is important information in the field of engineering. It determines the behavior of the soil when it suffers stress and strain. The degree of consistency of soil can do considerable influence on the water regime in the same, affecting the hydraulic conductivity for example.
The consistency of a soil refers to the degree of strength and plasticity of the soil that depend on the internal links between the particles. Cohesive soils have plastic consistency between specific limits moisture contents. Below these levels they have a solid consistency and above a liquid consistency. Therefore, the soil has two important properties to be analyzed, the Liquid Limit (LL) and the Plastic Limit (PL). The Liquid Limit is the moisture content that makes the soil has a liquid behavior. The Plastic Limit is the moisture content below which the soil becomes from the plastic state to the semi-solid state, which means it loses the ability to be shaped and starts to become brittle.
1.2) Purpose of Experiment
To determine the Liquid Limit, Plastic Limit, Plasticity Index and the soil classification according to UCS classification.
1.3.1) Liquid Limit
Dried Soil Sample Flat Grooving Tool
BalanceMixing and Storage Container
Liquid Limit Device
1.3.2) Plastic Limit
Ground Glass Plate Drying oven
Washing PanDried Soil Sample
For the Limit Liquid test, around 150 to 200g of soil was collected thought the No.40 sieve and placed into a mixing and storage container. After, it was added water in the sample and mixed in order to acquire the consistency for numbers of blows desired. The Liquid Limit Device was calibrated before the test be done. Then, first was collected a sample with the consistency for 15 to 20 blows for the Liquid Limit Device. The soil was placed into the cup of the Liquid Limit Device and it was squeezed down and spread into the cup to a depth of about 10mm, after it
References: (1)ASTM D 4643-00, “Standard Test Method for Determination of Water (Moisture) Content of Soil by the Microwave Oven Heating”. (2)Chug, Dr. Y., P., Carlton, C. (2014). “Laboratory Experiments Documentation”, Rock Mechanics: Principles and Design (MNGE: 431-4). (3) ASTM D 4618-00, “Liquid Limit, Plastic Limit and Plasticity Index of Soils”.