Crack Resistance and Width of Crack Opening of Beams with Hybrid Reinforcement Using BFRP and Metal Armature

The sustainable development of industry and society requires new approaches to the building structures design. The article presents the indices of strength, crack resistance and width of crack opening obtained as a result of experimental testing of beams with hybrid reinforcement with basalt plastic and metal armature. The following beams were examined for comparison purposes: the ferroconcrete beams of the control-series, and the twin beams reinforced only with basalt-plastic reinforcement. It was found that the replacement of the metal armature with basalt plastics led to an increase in strength, on average, by 40%. Similar strength indices were obtained for hybrid reinforcement beams. Crack resistance indices of hybrid reinforcement beams were found to be close to ferroconcrete beams of the control series. Crack resistance indices for these beams were also by 84... 89% higher in comparison with beams reinforced with basalt-plastics. The width of crack openings in hybrid reinforced beams did not exceed the maximum permissible norms at the operational level of loads (70% of destructive) and were smaller than in beams reinforced with basalt plastic reinforcement. Hybrid reinforcement efficiency has been established to improve the performance criteria of beams reinforced with composite armature.

Research of the Deflections of Beams Reinforced with BFRP Armature and Hybrid Reinforcement Using Metal and BFRP Armature

It is presented the study of the beam samples reinforced with metal armature, BFRP armature and beams with hybrid reinforcement using metal and BFRP armature. Half of the tested samples of beams were manufactured on concrete with river sand, as a fine aggregate. The others were made on concrete with fractionated fine wastes of Mining and Beneficiary complex (MBC) instead of the river sand. The tests were carried out by static loading of the scheme of a single-run free beam loaded in the thirds of gear. It was established that the beams reinforced with BFRP armature and the beams with hybrid reinforcement showed an increase of strength, about 40%, compared with the beams reinforced with metal reinforcement. The deflections of the beams reinforced with BFRP armature were 315% -331% higher than the deflections of the beams reinforced with metal reinforcement and 165% -205% higher than it is allowed by standards. The use of hybrid reinforcement allowed reducing their deflections in two times compared to the beams reinforced with BFRP armature. At a load level of 60% of the destructive, the deflections of beams with hybrid reinforcement BFRP and metal armature did not exceed the maximum permissible norm. When concrete samples manufactured, the substitution of the river sand with fine fractionated wastes from the Mining and Beneficiary complex (MBC) did not affect their durability and deformability (the difference between the values according to these indicators is within the statistical error).