Investigation of the effect of high temperature glass fibers and pozzolanic materials on flexural strength of concrete by pre-mixing and spraying method

Due to the thickness and low weight of the parts made of glass reinforced concrete, it is impossible to use reinforcement in the manufacture of these products. For this purpose, glass fibers are used to improve the concrete behavior under tensile and flexural loads and to increase the toughness. Glass fiber reinforced concrete can be used to make parts in different shapes and designs.This paper uses glass fibers and pozzolanic materials with different percentages. In order to investigate the flexural strength and toughness indices of concrete produced by pre-mixing and spraying methods, 15 mixing designs containing different percentages of glass fibers and pozzolanic materials in pre-mixed method and 14 mixing designs with spraying method have been tested. All mixing schemes were also tested at 350, 650 and 1000 ° C and the results were analyzed by scanning electron microscope (SEM). The use of pozzolanic materials in specimens reinforced with glass fiber improves the modulus of rupture. The modulus of rupture in the presence of heat and in the event of a fire is greatly reduced, which is a better performance for controlling this reduction process. Also, the flexural strength of high-temperature samples (1000 ° C) can be significantly increased by using methaquoline at different percentages of 10 and 15%.