Reclaimed rubber powder (RRP) was treated by the addition of maleic anhydride (MA) to impart desired properties suitable for self-adhesive sheets and concrete lining applications. The produced MA-RRP was mixed with natural rubber (NR) with various compositions. A fixed I : 1 blend ratio of NR : RRP was reinforced with various contents of glass fiber (GF) in an open two-roll mixing mill. The composites were irradiated using a 1.5 MeV electron beam accelerator at 30 and 50 kGy irradiation doses. Different properties of composite such as tensile strength, elongation at break, hardness, swelling behavior in different media, thermal stability, and scanning electron microscope (SEM) for both unirradiated and irradiated samples with respect to the RRP and GF content were investigated. Results show that the tensile strength and swelling resistance increase with increasing RRP content in the NR/RRP blends, whereas the elongation at break exhibit opposite trend. It can be observed that the hardness increases with increasing the fiber content. (c) 2007 Wiley Periodicals, Inc.