Tensile Splitting Strength
The splitting tensile strength test is a crucial evaluation method used to determine the tensile strength of hardened concrete. Small deviations in the water to cement ratio, ingredient proportioning, increase in a slump, etc. can significantly impact the desired strength of the concrete. As a result, it can also affect the strength and stability of structures built using the concrete. There are several other tests available to assess the strength of concrete, including compressive strength, flexural strength, and water absorption tests, among others. It is vital to conduct quality tests at various stages during construction to ensure the concrete's overall quality and the safety and durability of the structures built with it.
Significance of Splitting Tensile Strength Test in Concrete
The tensile splitting strength test is a crucial evaluation method for determining the tensile strength of concrete. Concrete is brittle and weak in tension, making it susceptible to cracking. The splitting tensile strength test is an indirect method of testing the tensile strength of concrete. It involves splitting a cylinder across its vertical diameter to measure the force required to do so. At least three samples should be tested, and an average value is calculated to ensure accurate results.
The primary objectives of the splitting tensile strength test are as follows:
Determining Tensile Strength: The test helps determine the tensile strength of concrete, which is essential for understanding the overall strength and durability of the concrete structure.
Assessing Sand and Aggregate Use: The test provides information on the use of sand and aggregate in concrete, helping to optimize the mixture and improve the strength of the final product.
Uniform Stress Distribution: The test helps determine the uniform distribution of stress within the concrete, which is essential for ensuring the structure's stability and durability.
Studying Concrete Behavior: By studying the behavior of concrete under tension, the test provides valuable insights into the material's properties and helps to optimize its use in construction.
In summary, the splitting tensile strength test is a critical evaluation method for ensuring the quality and durability of concrete structures. By understanding the material's tensile strength, uniform stress distribution, and behavior under tension, builders can optimize the use of concrete and construct structures that are safe, stable, and long-lasting.
Test Method
To conduct the splitting tensile strength test on concrete, the following steps should be followed:
Preparation of the cylindrical specimen: Prepare the concrete mix according to the desired proportions and pour it into the cylindrical mould. Grease the inside surface of the mould before pouring the mix. Compact each layer using a tamping rod and tap each layer 30 times. Uniformly stroke the concrete mix and remove the excess concrete.
Curing of the specimen: Immerse the casted specimen in water for 24 hours at 27-degree Celsius. After that, remove the specimen from the mould and immerse it in freshwater.
Testing of the specimen: Conduct the splitting tensile strength test at 7 and 28 days of curing. Before starting the test, take the specimen from the immersed water and wipe the water. Then note the dimension and weight of the specimen. Place plywood strips above and below the specimen and place it on the testing machine. Gradually apply the load at a rate of 0.7 to 1.4 MPa/min (1.2 to 2.4 MPa/min based on IS 5816 1999). Record the load at which the specimen breaks.
Calculation of splitting tensile strength: To calculate the splitting tensile strength of concrete, use the formula T = 2P/ Ω LD, where T is the splitting tensile strength, P is the load at which the specimen breaks, Ω is the correction factor (0.7 for standard specimen), L is the length of the specimen, and D is the diameter of the specimen.
The unit of tensile strength is N/mm. The splitting test is a simple, reliable and convenient method to determine the strength of concrete. It provides uniform results and can be easily performed.
Method references:
IS 5816
ASTM C496