Improvement of Mechanical Properties of Mortar Reinforced by Cold Plasma Treated Polypropylene Fibres

摘要

An addition of polypropylene fibres can reduce cracking mainly in early age of concrete. However utilization of full potential of those fibres is limited by low cohesion of the polypropylene with cement matrix. This can be solved by application of Diffuse Coplanar Surface Barrier Discharge which can cause exchange of hydrogen atoms into hydroxyl groups; the outcome is change of contact angle between water and surface of the polypropylene. The method is highly effective since it affects the surface only; the rest of the fibre remains unchanged. The paper presents results of flexural and compressive strength obtained on mortar samples 4*4*16 cm. The data proved increase of cohesion after plasma treatment mainly in early age of 12 hours after mixing.