Plastic limit is determined by repeatedly remolding a small ball of moist plastic soil and manually rolling it out into a 1/8in thread. A plastic limit roller device can also be used to perform this test. The plastic limit is the moisture content at which the thread crumbles before being completely rolled out.
How to Find Plastic Limit?
Finding the plastic limit of soil is an important step in determining the consistency of the soil. The plastic limit is the moisture content at which a soil changes from a solid to a plastic state, and is a key factor when it comes to engineering and construction projects.
Knowing the plastic limit of a soil can help engineers determine the best construction materials and methods for the job. When it comes to finding the plastic limit of a soil, the most reliable method is the Casagrande Method.
This method requires soil samples of known moisture content and a standardized apparatus. A Casagrande Apparatus is used to measure the moisture content of the soil sample, and a standard sample container is used to collect the sample.
The apparatus is also used to shape the soil sample in preparation for testing. Once the sample is collected and the apparatus is set up, the soil sample is placed into the apparatus and the moisture content is measured.
The sample is then rolled into a three–millimeter thick thread, and the thread is divided into three equal parts.
The plastic limit is determined when two of the three parts bind together and can be rolled into a thread of three millimeters thick. The Casagrande Method is a reliable and accurate method for determining