CRACK-RESISTANCE OF A CONTINUOUS COMBINED-REINFORCED CONCRETE BEAMS WITH DIFFERENT TYPES OF STEEL FIBER REINFORCEMENT
DOI:
https://doi.org/10.31713/budres.v0i37.333Abstract
Perspective direction of concrete structures improvement are increasing their strength, hardness and shear strength by using statically indeterminate structures. Special place is occupied by statically indeterminate (continuous) reinforced concrete beams, as they most efficiently used components materials - concrete and reinforcement.
The dispersed-reinforced materials, including steel fibrous concrete are the one of most promising structural materials. Interest of using of fiber-reinforced concrete has been increasing, which can be explained by the desire to significantly increase the compressive strength of concrete materials and structures, tensile strength, shear strength, get effective structures which would respond to higher operational requirements. Due to the mixed reinforcement of concrete beams, work of concrete in stretched zone can be effectively used.
The article presents the results of experimental studies of behavior and crack resistance of concrete beams with combination of classic and steel fibrous reinforcement under operating loads. Experiments were conducted with 300 cm long two-span beams which were made from heavy concrete The size of the cross section was 10x16 cm. The length of spans was 140cm. The volume percent of fiber reinforcement was accepted 1%.
Testing of beams was carried in special force device, where with the hydraulic jack, was made loading, and through the cross-arm it was applied to the beams in two equidistant from central support points. During research was determined deflections, deformations of edge concrete fibers and crack width.
During the research, new experimental data were obtained, on the basis of which it can be concluded that the use of additional disperse reinforcement of steel fibers of the stretched zones of continuous reinforced concrete beams, allows to increase the rigidity of the elements, to increase their crack resistance and durability.