The quality of concrete is tested by using following experiments and tests :-
1. Workability or consistency
Possible tests for workability or consistency include :-
a. Slump test by means of the standard ASTM code. The slump in inches recorded in the mixture indicates its workability
b. Remolding tests using Powers’ flow table.
c. Kelly’s ball apparatus
2. Air Content
Measurement of the air content in fresh concrete is always necessary, especially when air entraining agents are used.
3. Compressive Strength of Concrete
This is done by loading cylinders 6 in. in diameter and 12 in. high in compression perpendicular to the axis of the cylinder. For high-strength concrete, cylinders 4 in. dia. X 8 in. – height can be used applying proper dimensional correction.
4. Flexural strength of Plain Concrete Beams :-
This test is performed by three-point loading of plain concrete beams of size 6 in. x 6 in. x 18 in. that have spans three times their depth.
5. Tensile Splitting Tests
These tests are performed by loading the standard cylinder by a line load perpendicular to its longitudinal axis with the cylinder placed horizontally on the testing machine pattern.
