Uniaxial Compressional Stress‐Strain Relation of Concrete

A new formula that represents both ascending and descending portions of uniaxial compressional stress-strain relation is suggested. This formula consists of two parameters, one governing the steepness of ascending portion and the other controlling the steepness of descending portion. For all possible variations of the parameters, the suggested formula implicitly satisfies the basic properties of a complete stress-strain relation that the stress ascends, reaches its peak value, and then descends, as the strain increases. Expressing the parameters in term of concrete strength, the suggested formula automatically satisfies the behavior of concrete under uniaxial compression that the descending portion becomes steeper as concrete strength is higher. Using the suggested formula, the entire range of strength-stress relation can be favorably determined upon comparing to available test data.