POLYPROPYLENE FIBERS MODIFIED BY ATMOSPHERIC PRESSURE PLASMA AS REINFORCEMENT FOR CONCRETE

This contribution deals with the atmospheric pressure plasma treatment of PP fibers that leads to the increase of surface energy of polypropylene and the improvement of cohesion of PP fibers to cement matrix as well. The plasma modification was performed by Diffuse Coplanar Surface Barrier Discharge operating at atmospheric pressure in ambient air. The surface energy of PP fibers was studied by the method based on the measurement of the weight of absorbed water as a function of time. The change in cohesion was tested by restrain shrinkage test on mortar samples. It was confirmed that the plasma treatment improved the surface wetting properties of PP fibers and the mechanical performance of the plasma treated PP fibers reinforcing concrete.