Properties of Para-Rubber Plates Using as the Capping on Concrete Specimens for Compression Test Instead of Molten Sulphur

Abstract

This paper aims to study the using para-rubber plate for transferring the force on concrete specimens instead of capping with sulphur. Four formulas for mix design of para-rubber plate are setup. Each formula is mixed in two rolls mill machine and formed the para-rubber plate by Compression Molding. After obtaining the para-rubber plate specimens, the measuring of compression set, tensile strength, 7o sttain, tear strength, hardness of para-rubber plate are performed. Consequently, the para-rubber plates are taken into capping the concrete and tested the compressive strength. These results are compared to that with sulphur capping. From the results, it is found that adding carbon black over 60 phr affects to develop the hardness but the other properties are declined. In testing the compressive strength of concrete with para-rubber plate, it is found that the formula having the results close to that using of sulphur is the formula that using latex at 100 phr, carbon black (grade N330) at 100 phr and calcium carbonate at 50 phr. In this formula, the compressive strength is larger than using sulphur at 7Vo. This indicates that there is possibility in developing the formula of para-rubber plate for capping material in the future