Tests on Building Stones – Strength and Properties of Stones

Building stones are subjected to a variety of tests to determine their qualities and suitability for various construction projects. Physical and chemical qualities, as well as strength and hardness properties, are determined through testing building stones. This test is used to determine whether or not construction stone contains calcium carbonate. A stone sample weighing between 50 and 100 grammes is taken. It is immersed in a one percent solution of hydrophobic acid and left there for seven days. At regular intervals, the solution is stirred. At the end of this period, a good building stone maintains its sharp edges and preserves its surface free of powder. The presence of calcium is indicated if the edges are shattered and powder forms on the surface.

Building Stone Attrition Test

This test is carried out to determine the rate of wear of stones used in road construction. The results of the test show how resistant stones are to grinding under traffic.The procedure used is as follows: Stone samples are split into 60mm-sized pieces. These 5 kilogramme chunks are placed in both cylinders of Devil’s attrition test machine. The cylinder’s diameter and length are 20 cm and 34 cm, respectively. The cylinders have been closed. Their axes form a 30 degree angle with the horizontal. Cylinders are rotated at 30 rpm for 5 hours around the horizontal axis. The contents of the cylinders are removed after this time period.

Stone samples are cut into 40 x 40 x 40 mm cubes, which are then properly dressed and finished. Three specimens are the maximum number that can be tested. Such specimens should be submerged in water for 72 hours prior to testing and tested in a saturated state. The load-bearing surface is then covered with 5mm thick plaster of Paris plywood. In a crushing test machine, the load is imparted axially to the cube. The loading rate is 140 kg/sq.cm/min. The greatest force at which the sample crushes or fails divided by the area of the bearing face of the specimen is the crushing strength of the stone per unit area.

Building Stone Crystalline Test

At least four stone cubes with sides of 40mm are required. They are weighed after 72 hours of drying. After that, they are immersed in a 14 percent Na2SO4 solution for two hours. They are weighed after being dried at 100 degrees Celsius. It is noticed that there is a weight difference. This drying, weighing, submerging, and reweighing operation is repeated at least five times. Each time, the weight change is recorded and expressed as a percentage of the initial weight. Weathering causes the stone to deteriorate due to the crystallisation of CaSO4 in the pores. However, because CaSO4 has a limited water solubility, it is not used in this test. Test of freezing and thawing For 24 hours, a stone specimen is soaked in water. After that, it’s placed in.

To avoid any effects from wind, sun rays, rain, and other factors, this should be done in the shade. This method is repeated multiple times while the stone’s behaviour is closely monitored. Building Stone Hardness Test The following procedure is used to determine the hardness of a stone: The stone sample is cut into a cylinder with a diameter of 25mm and a height of 25mm. It has been weighed. The sample is placed in Dorry’s testing machine and put under 1250 grammes of pressure. Then, at a speed of 28 rpm, the annular steel disc machine is revolved. The top of the disc is dusted with coarse sand of standard specification while it rotates. The specimen is removed after 1000 revolutions.

Microscopic Test

A microscopic examination of the test sample is performed. Stones are cut into slices and examined under a microscope to determine their various qualities, such as density. Grain size on Averages Ores, cracks, veins, and shaking are all present.Composition of minerals Cementing material’s nature Existence of any potentially dangerous material Stone texture, for example. The Smith Test This test is used to determine the presence of soluble materials in a stone sample. A few stone chips or fragments are collected and placed in a glass tube. After that, the tube is filled with pure water. The tube is aggressively stirred or shook after roughly an hour. The presence of earthy materials in the water will turn it from clear to muddy. Stone will remain transparent if the water remains clear.

Test for Water Absorption The following is how the test is carried out: A cube weighing around 50gm is made from the stone sample. W1 gramme is the actual weight of the item. After that, the cube is immersed in distilled water for 24 hours.The cube is removed from the water and the excess water is wiped away with a moist cloth. It is weighed once more. Let W2 gm be the weight. The weight of a cube suspended in water is recorded. Let’s call this W3 gm.The water is brought to a boil, and the cube is immersed in it for 5 hours. Surface water is wiped off with a moist cloth when the cube is removed. Its weight is kept track of. Let’s say it’s W4 gm. Values are derived from the above observations.

Impact test on building stone

The alternate wetting and drying test is carried out. A saturated solution of sodium sulphate or magnesium sulphate is used instead of water in alternate wetting and drying tests, as well as freezing and thawing tests, to speed up the impact.The fine aggregate to be tested is washed and dried at 105 to 110 degrees Celsius before being immersed in a saturated solution of sodium sulphate or magnesium sulphate for not less than 16 hours and not more than 18 hours in a wetting and drying test. At a temperature of 20 degrees Celsius.After that, the stone chip is withdrawn from the solution, drained, and dried at 105 to 110 degrees Celsius before being allowed to cool to room temperature.

This completes one wetting and drying cycle. Before a test, the material is sieved on the same sieve on which it was kept, and the weight of material on each sieve is recorded. (Building Stone Test) Each fraction of the material should be visually checked to see if there are any signs of severe grain splitting. Splitting, crumbling, cracking, flaking, and other forms of disintegration are possible. The weight reduction % on each sieve is thus calculated. Building stone was put to the test.

Test of attrition

This test is performed using a deval attrition machine. It is made up of 20 cm iron hollow cylinders. 34 cm in diameter on the inside. The axis of rotation is positioned diagonally at 30 degrees on the inside length. The horizontal position of the rotating axle is maintained. A 5kg stone that has been broken into 2*(1/2) rings is carefully washed and dried for 24 hours at 105 to 1110°C. These stones are then inserted inside the cylinder, which is finally sealed. For the 10000 rotations, a motor rotates the cylinder along its axis at a rate of 30 revolutions per minute.

In a test on construction stone, an impact testing machine is employed. The stone sample is cut into a cylinder with a diameter of 25mm and a height of 25mm. It’s inserted into the machine. And put in a 2kg stone sample after 24 hours.

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