Explanation of testing on hardened concrete

1. By
Mohammed Nishmal K
2ab15cv024

2. Compression Test
 ASTM C39: cylindrical specimen (6 in. by 12 in.)
 For normal-weight concrete: fc’ range is 21 MPa to 34
MPa (3000 psi to 5000 psi)
 Compressive strength depends on specimen size
 Larger specimens = greater probability for weaker
elements, reducing strength
 Larger specimens have less variability and better
representation of actual concrete

4. Split tension test
 Measures the tensile strength on concrete (ASTM C496)
 Cylinder is subjected to compressive load along vertical
diameter at a constant rate until fatigue
 Failure occurs along vertical diameter due to tension
developed in transverse direction
 Split tension is computed by T = 2p/BLD
 T = tensile strength, MPa (psi)
 p= load at failure, N (psi)
 L = length of specimen, mm (in.)
 D = diameter of specimen, mm (in.)
 Tensile strength varies from 2.5 MPa to 31 MPa (360 psi to
450 psi), about 10% of compressive strength

6. Flexure strength test
 Used for measuring Modulus of Rupture (MR)
 Important test for road and airport concrete pavements
 Beam specimen of square x-section is loaded into a 3-point loading apparatus·
 Calculation of MR
 If the fracture occurs in the middle 1/3 of the span
 R = PL/(bd^2)
 Where:
 R = flexure strength, MPa (psi)
 P = maximum load applied, N (lb)
 L = span length, mm (in.)
 b = average width of specimen, mm (in.)
 a = average depth of specimen, mm (in.)
 If fracture occurs further outside the middle third, the results must be thrown
out

8. Thank You