ASTM C496/C496M-11 pdf free download.Standard Test Method for Splitting Tensile Strength of Cylindrical Concrete Specimens.
1.1 This test method covers the determination of the splitting tensile strength of cylindrical concrete specimens, such as molded cylinders and drilled cores.
1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents: therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
3. Summary of Test Method
3.1 This test method consists of applying a diametral compressive force along the length of a cylindrical concrete specimen at a rate that is within a prescribed range until failure occurs. This loading induces tensile stresses on the plane containing the applied load and relatively high compressive stresses in the area immediately around the applied load. Tensile failure occurs rather than compressive failure because the areas of load application are in a state of triaxial compression, thereby allowing them to withstand much higher compressive stresses than would be indicated by a uniaxial compressive strength test result.
3.2 Thin, plywood bearing strips are used to distribute the load applied along the length of the cylinder.
3.3 The maximum load sustained by the specimen is divided by appropriate geometrical factors to obtain the splitting tensile strength.
4. Significance and Use
4.1 Splitting tensile strength is generally greater than direct tensile strength and lower than flexural strength (modulus of rupture).
4.2 Splitting tensile strength is used in the design of structural lightweight concrete members to evaluate the shear resistance provided by concrete and to determine the development length of reinforcement.
5. Apparatus
5. 1 Testing Machine—The testing machine shall conform to the requirements of Test Method C39/C39M and he of a type with sufficient capacity that will provide the rate of loading prescribed in 7.5.
5.2 Supplementary Bearing Bar or Plate—If the diameter or the largest dimension of the upper bearing face or the lower bearing block is less than the length of the cylinder to be tested, a supplementary bearing bar or plate of machined steel shall be used. The surfaces of the bar or plate shall he machined to within ± 0.025 mm [± 0.00l in.] of planeness, as measured on any line of contact of the hearing area. It shall have a width of at least 50 mm [2 in.], and a thickness not less than the distance from the edge of the spherical or rectangular bearing block to the end of the cylinder. The bar or plate shall be used in such manner that the load will be applied over the entire length of the specimen.ASTM C496/C496M pdf download.