Detailed tests on building lime are conducted in laboratory as per Indian Standard code, IS 6932-1973 to check quality and composition of lime suitable as a building material.
These tests on building lime is generally are divided into two main classifications: the routine tests and the special tests. A detailed explanation of different tests that comes under each of this classification is explained below.
Laboratory Tests on Building Lime as per Indian StandardsThe different test that is conducted under routine tests on building limes are:
1. Determination of Residue on the Slaking of LimeThis test is provided in IS 6932 (Part 3). Initially, the sample for testing is sieved through 2.36mm IS sieve. The residue if present is broken and again it is sieved. The process is repeated till the whole sample pass through the sieve. The quantity of water that is required for the slaking is equal to four times the mass of the quicklime. Note: For high calcium lime the amount of water will be equal to eight times the mass of the sample. Two samples must be prepared, of quicklime, with a weight of-of, 5 kg is slaked, by adding them in smaller quantities with the water in required quantity. This must be maintained at 50 and 100 ± 2 degree celsius with 5 minutes. The mix is continuously stirred continuously at this temperature maintained, and allow to stand for 24 hours. In this standing period, only twice the stirring is carried out. The last stirring is carried out one hour before the commencement of the standard 24 hours. The supernatant liquid is allowed to pass through an 850 micron IS sieve then through a 300 micron IS sieve. The remaining is again stirred and again passed through the same sieve. The residue that is obtained is washed and dried at a temperature of 100±10 degree Celsius to a constant mass. The residues are obtained for two samples that are weighted separately and designated as the percent of the mass of the quicklime test sample.
2. Fineness Test on Building LimeThis test is carried out based on IS: 6932 (Part 4). A 100 g of hydrated lime is undergone sieve test. The arrangement consists of sieves arranged in such a way that the coarser sieves are placed at the top in a decreasing manner. With the help of a moderate jet of water, the hydrated lime is washed through the sieve from the top, in not more than 30 minutes. The Residue on each of the sieve is dried at a temperature of 100±10 degree Celsius to a constant mass and is weighed. The obtained is percentage mass of the hydrated lime sample.
3. Workability Tests on Building LimeWorkability tests on building lime is carried out in the standard flow table that is shown in the figure below.
Fig.1: Standard Flow Table Apparatus for Workability of Building LimeTo test the hydrated lime, at a temperature of 27 ± 2 oC 500g of hydrated lime is mixed with an equal mass of water. This mixture is allowed to stand for 224 hours. The material is allowed twice to pass through the mixer, to make a form of plastic putty. The lower part of the lime putty is spread to a thickness of 110 mm when it is subjected to a bump in the standard flow table. No deviation more than 1 mm is expected. More water is added if it is stiff. If water is more, it is allowed to withdraw, by placing over a dry absorbing surface. This is how the lime putty sample will acquire the standard consistency. This sample is filled inside the molds. The temperature maintained is 27 ± 2 oC. Care is taken not to fill the molds with air bubbles. The top of the cone is cleaned and leveled. The cone with the material is placed in the center of the table, and the mold is removed At a rate of one turn per second, the handle of the table is turned. The spread of material is the average of three diameters that are measured with a 60-degree gap. This is actually average diameter that is obtained.