Concrete modification by using polymeric materials has been studied since the nineteen sixties. Some polymers are already used to modify the properties of concrete. The materials used currently to reinforce the concrete matrix adhere only by physical interactions and not by primary chemical bonds.

A new alternative that is being evaluated is the use of gamma radiation to modify the material surface. This increases the compatibility with concrete matrix. The enhanced compatibility would allow improving both modulus and compressive strength. Typically PP fiber is first irradiated to several dosages of gamma rays and then incorporated in concrete. It is observed that at about 1.5-2 % level of of irradiated PP fiber improves the performance of concrete in both modulus as well as compressive strength. Typically radiation dosage of about 10 kGy is adequate.

Thus performance of concrete can be improved by the use of irradiated PP fiber.