(iv) Tensile strength of concrete

The flexure and split tensile strengths of different types of concrete are provided in IS 516:1959 and IS 5816:1970 respectively when the designer wants to utilize an estimate of the tensile strength from compressive strength, the following formula should be applied.

Flexural strength, fcr=0.7√fck

N/mm2 (v) Elastic Deformation

The modulus of elasticity is mainly dependent on the elastic properties of the aggregate and to lesser extent on the conditions of curing and age of the concrete, the mix proportions and the type of cement. The modulus of elasticity is generally associated with the compressive characteristic strength of concrete.

Ec=5000√fck N/mm2

Here Ec denotes the short-term static modulus of elasticity in N/mm2

fck denotes the characteristic cube strength of concrete in N/mm2


(vi) Shrinkage of concrete

Shrinkage is the time dependent deformation, usually compressive in nature. The ingredients of concrete, size of the member and environmental conditions impact the shrinkage of concrete. However, the total shrinkage of concrete is primarily based on the total amount of water found in the concrete while mixing it for a given humidity and temperature. The estimated value of the total shrinkage strain for design is considered as 0.0003 in the absence of test data.


(vii) Creep of concrete

Creep is another time dependent deformation of concrete by which it continues to deform, generally under compressive stress. The creep strains recover partially when the stresses are discharged.