Parametric study of glass fiber reinforced concrete

Abstract

Increasing the durability of structures is necessary for sustainability and low life cycle cost. With passage of time and exposure to various harsh environments many reinforced concrete (RC) structures begin to degrade. Early degradation of the structures is caused due to the development of minor fissures and cracks in concrete. Early development of cracks starts from the moment the structure is cast due to shrinkage. These micro-cracks propagate further upon loading and give entry to water, CO2 or other gases up to reinforcement. Small discrete glass fibers when added to concrete reduce the cracking and increase durability. Durability tests generally carried at laboratory don’t consider the effect of cracks due to loading on structure on durability of concrete. Present studyfocuses on understanding the effect of glass fiber and loading on the durability ofconcrete. To know the effect of loading on structures under service, on the durability of concrete, cubes were loaded to 60 % of the expected ultimate load. This load may open the cracks already existing in the concrete and created more cracks. After loading cubes were subjected to 100 drying and wetting cycles. After drying and wetting cycles, ultrasonic pulse velocity and compressive strengthwere investigated. About 20 % increase in case of fibre reinforced concrete was reported over control concrete. Tested samples had also shown more than 10 % improvement in the compressive and flexural strength. However the slump has reduced from 20 to 0 mm for fiber reinforced concrete.