The impact of percentage content of basalt fiber-reinforced polymer and steel reinforcement on the strength indicators of experimental beams with hybrid reinforcement

Abstract

The use of composite reinforcement in the structures subject to bending is limited due to their excessive deformation. One way to overcome this shortcoming is to use hybrid reinforcement where steel and composite reinforcement are used in combination. The effectiveness of this approach has been proven by previous studies. There are no studies on the establishment of the effective ratio between steel and composite elements. This paper presents the results of tests of prototype beams with hybrid reinforcement made of basalt fiber-reinforced polymer (BFRP) and steel. A total of 12 series of samples of beams, three beams in each series, were studied. The percentage of both types of reinforcement was variable; it varied from a ratio of 100% / 0% to 0% / 100% in increments of ~ 20% (the numerator of the fraction corresponds to the percentage of steel reinforcement, and the denominator – to the percentage of BFRP reinforcement). According to the results of tests of beams by static loading, it was found that the use of hybrid reinforcement allowed to increase the bearing capacity of the samples by 33% – 74%, depending on the percentage of reinforcement in the cross section, compared with the beams of the control series. Based on the nature of breaks and load-bearing capacity, the most optimal ratio of steel and BFRP reinforcement was 60% – 40%. The optimal percentage of cross section reinforcement is 1.07%.