Standard sand is a significant part used by experts for cement testing. Instruments used for preparing cement and asphalt mix require standard sand to ascertain the quality testing of building materials. Standard sand is not only meant for testing building materials, but also used as standard material to examine and study properties of other materials like lime and pozzolona, several admixtures and for determination of abrasion resistance for constructing stones.
How to determine whether the sand is standard or not?
There are several physical properties of standard sand that makes it different from other varieties. A few of them are as under-
- Standard sand is of light gray or whitish in color and doesn’t hold any silt content.
- Standard sand is made of quartz.
- Particle should be angular in shape.
- Standard sand should be retained on 90 micro IS Sieve.
- Standard sand should be pass through 2mm IS Sieve.
As far as chemical properties are concerned, standard sand should not contain organic impurities.
How to check quality of cement?
It is important to check the cement quality on site at the time of preliminary inspection. It is not possible to ensure all engineering qualities of cement on site, but there are special field test that will provide you rough idea of cement quality. While on site, you can perform these field tests to determine cement quality, the steps are as under-
- Date of packing- Date of packing should be checked properly and don’t forget to see the date of manufacturing on the bag. It is very critical thing as the strength of cement reduces with age.
- Color- Color should be uniform. In general, cement color should be grey with a light greenish tone. Cement color will explain and tell you the present amount of lime or clay and the degree of burning.
- Rubbing- take a pinch of cement and rub it between fingers. If it feels smooth, it is of good quality. Rough particles indicate that the sample is adulterated with sand.
- Hand use- Insert your hand in the cement bag and make sure it should feel cool. If it doesn’t give you cool feeling, it means any hydration reaction is happening in the bag.
- Float test- If the cement sink in the water, it is of good quality.
- Smell test – if it smells earthy, it contains clay and silt as adulterant.
- Lumps check- Lump free cement is preferable for use.
- Shape test- Good quality of cement has ability to set under water.
- Pros & Cons Non Destructive Testing Application
- Strength test
You can still use other cement quality testing instruments to perform cement, concrete, and asphalt testing.