BS 1377 : 1990 – 2 Determination of the plastic limit and plasticity index, giới hạn dẻo và chỉ số dẻo

BS 1377 : 1990 – 2 Determination of the plastic limit and plasticity index, giới hạn dẻo và chỉ số dẻo

5.1 General

The plastic limit is the empirically established moisture content at which a soil becomes too dry to

be plastic. It is used together with the liquid limit to determine the plasticity index which when plotted

against the liquid limit on the plasticity chart (see BS 5930) provides a means of classifying cohesive soils. It is recognized that the results are subject to the judgement of the operator, and that some variability in results will occur.

BS 1377 : 1990 – 2 Determination of the plastic limit and plasticity index, giới hạn dẻo và chỉ số dẻo

5.2 Sample preparation

Samples for test shall be prepared as specified in 4.2. The soil shall not be allowed to become dry before testing. Where air drying is required the method used shall be stated. Drying and breaking down procedures shall comply with 7.3.4, 7.3.5 and 7.4.3 of BS 1377-1:1990. It is convenient to carry out the test on a portion of the material prepared for one of the liquid limit test procedures specified in clause 4.

BS 1377 : 1990 – 2 Determination of the plastic limit and plasticity index, giới hạn dẻo và chỉ số dẻo

5.3 Method for plastic limit

5.3.1 General.

This method covers the determination of the plastic limit of a soil sample, i.e. the lowest moisture content at which the soil is plastic. The sample shall be of soil in its natural state, or of soil from which material retained on a 425 µm test sieve has been removed. The requirements of Part 1 of this standard, where appropriate, shall apply to this test method

5.3.2 Apparatus
5.3.2.1 A flat, glass plate, as specified in 4.3.2.1, on which the soil is mixed.
5.3.2.2 A flat, glass plate, smooth and free from scratches, on which threads are rolled. A convenient size of plate is about 10 mm thick and 300 mm square
5.3.2.3 Two palette knives or spatulas.
5.3.2.4 Apparatus for the moisture content determination of fine-grained soils as specified in 3.2.2.
5.3.2.5 A length of rod, 3 mm in diameter and about 100 mm long.
5.3.3 Procedure
5.3.4 Calculations and expression of results
5.3.5 Test report.

BS 1377 : 1990 – 2 Determination of the plastic limit and plasticity index, giới hạn dẻo và chỉ số dẻo

The test report shall affirm that the test was carried out in accordance with BS 1377-2:1990 and shall include the following information:

  1. a) the method of test used;
  2. b) the plastic limit of the soil sample;
  3. c) the percentage of material passing the 425 µm test sieve;
  4. d) the history of the sample, e.g. whether tested in the natural state, or after wet sieving or after any other process;
  5. e) The information required by clause 9 of BS 1377-1:1990

Xem và tải  file pfd BS 1377 : 1990 – 2 Determination of the plastic limit and plasticity index, giới hạn dẻo và chỉ số dẻo theo link bên dưới – nguồn xaydung360

BS 1377 1990 – 2 Determination of the plastic limit and plasticity index

Call Now Button
Contact Me on Zalo