In order to determine effects cf part replacement of cement by pozzolans and of entrainment of air on the bond to steel strength of concrete with plain and deformed bars, series of laboratory studies were carried out on concretes of different strengths using air-entraining and pozzolanic admixtures. The studies revealed that the part replacement of cement by pozzolan affects the bond to plain bars to the same adverse degree as the compressive strength but the bond to the deformed bars is not so adversely affected. The entrainment of air does not materially affect the bond strength of concrete.
The experimental data obtained is helpful in arriving at the unit stress for bond to be used in the design of R.C.C. using concretes having pozzolanic materials and entrained air in them, both with plain and deformed bars.
