The standard of building stones with the stone abrasion test method due to traffic was prepared and compiled by the relevant technical commission and was approved by the 61st meeting of the National Committee for Construction Standards and Materials dated 9/18/2000 and as a national standard is published.
In the preparation and compilation of this standard, it has been tried to create harmony between this standard and the national standards of industrialized and advanced countries, while paying attention to the existing conditions and the needs of the society.
The sources used to prepare this standard are: ASTM-C 241-85
- Purpose and scope of application
The purpose of this standard is to determine the abrasion resistance of all types of stepping stones, floors and the others which are subject to surface abrasion caused by people’s traffic.
- The importance and application of this standard
This test determines the abrasion resistance of different types of building stones used in stairs, floors and … to make its comparison possible.
- Test device
The device for determining the abrasion resistance of stone includes two abrasive plates with a diameter of 250 mm, which rotates at a speed of 45 revolutions per minute. According to the figure below the page
- Sampling
The sample should represent the real average of the type or grade of the stone. Also, the sample must have a thickness of 25 mm and a surface of 200 square millimeters so that at least three samples with a polished surface can be prepared from it. The sample can be chosen by the buyer or his legal representative.
- Exams
At least three samples with an area of 50 square millimeters and a thickness of 25 millimeters should be cut from each sample. To prevent crushing during the test, the edges of the test pieces should be rounded to a radius of approximately 0.8 mm.
- Test conditions
The samples should be dried for 24 hours at a temperature of 105+2 degrees Celsius. If the test is done immediately after cooling the samples, there is no need to put them in a desiccator.
- Test method
The samples should be weighed with an accuracy of 0.01 grams and then placed in the grinding machine and rubbed with an abrasive material at a speed of 235 revolutions per minute. Then remove the samples from the machine and clean their surface completely and weigh them with the same accuracy of 0.01 grams. Place the samples in water for at least one hour, then take the samples out of the water and dry their surface with a towel and weigh them. Also determine the weight of the test in water. The density of the sample is calculated according to the method specified in the national standard number 5699 of Iran.
Reminder – due to the fact that the amount of moisture is effective in the amount of abrasion of some stones. It is recommended that the test be performed when the relative humidity of the sample is 3-7%.
- Calculations:
The abrasion resistance of the test piece is calculated according to the following formula:
Abrasion resistance =10ca(200+Ws)/2000Wa
With thanks for your attention
Meghdad Shfiei
