TO DETERMINE THE COMPRESSIVE STRENGTH OF CEMENT USING MORTAR CUBES
- Weighing balance
- Glass cylinder
- Cube mould (2” x 2” x 2”)
- Cement, sand passing US sieve # 20 and retained on US sieve # 30
- Distilled water.
Standard followed is ASTM C109 / C109M – 16a.
Take one part of cement and three parts of sand and add 10% of the water of total dry material.
- For one mould the amount of water and the quantity of dry material that will be mixed at one time will be calculated as follows.
- 70 grams of cement.
- 210 grams of sand.
- 28 cc of water.
- After preparation of mix, the required no. of mould should be filled. The tamping pressure shall be just sufficient to ensure uniform filling of mould. The layer of mortar about 1 inch thick is first placed in the mould and tamp 20 times with the tamper. Then fill the mould with mortar and tamper as specified for the first layer.
- After completion of the filling, place the moulds in moist air for 24 hours.
- After 24 hours de-mould the specimens and immerse them in water for the required age.
- After three days take out three specimens of the same type of cement, and keep them in open air, wiped to surface dry condition before test.
- Apply the load to the specimen faces that were in contact with the plane surfaces of the mould. Carefully place the specimen in testing machine below the center of the upper bearing block.
- Record the total maximum load indicated by the testing machine and calculate the compressive strengths in Mega-Pascal.
OBSERVATIONS AND CALCULATIONS
Observations and calculation of compressive strength of cement mortars are reported in this table format.
|S. No.||COMPRESSIVE STRENGTH (MPa)|
|1 DAY||3 DAYS||7 DAYS||28 DAYS|
Depending on types of results comments can be written at the end of the report.