OPTIMUM UTILIZATION OF POLYPROPYLENE FIBRE IN CONCRETE.

Conventional concrete is acknowledged to be relatively brittle material when subjected to normal stresses and impact loads. Tensile strength of concrete is approximately one tenth of its compressive strength. Concrete also possesses poor deformability and weak crack resistance in practical usage. These drawbacks limit the use of concrete. To do away brittle nature of concrete, application of discrete fibre in concrete construction has been proposed. In an attempt to increase the durability and load carrying capacity of concrete, reinforced concrete has been introduced. This study is the part of research work on evaluating the optimum use of fibre in concrete. The aim of the investigation is to determine the effect of variation of polypropylene fibre ranging from 0% to 1% with increment of 0.25%. The fibre was used as an additive in concrete with content of 0%, 0.25%, 0.50%, 0.75% and 1% for M-20 mix. Concrete mixes were produced, tested and compared with the conventional concrete mix in the terms of workability, compressive strength and splitting tensile strength. The tests were carried out after 7, 14 and 28 days of curing. The workability of concrete decreases with the increase in polypropylene fibre content. The gradual increase was seen in compressive strength and splitting tensile strength of fibre reinforced concrete up to 0.5% of fibre content for all curing ages. Beyond that there is a significant reduction in strength. The maximum compressive strength and splitting tensile strength were 28.52 N/mm[sup 2] and 3.75 N/mm[sup 2] respectively. Fibre addition was seen to enhance the physical and mechanical properties of concrete. [ABSTRACT FROM AUTHOR]