Reforço e incremento da rigidez à flexão de ligações viga-pilar de estruturas de concreto pré-moldado com polímero reforçado com fibra de carbono (PRFC)

Abstract

This work presents a technique for flexural strengthening and stiffness increasing of precast beam-to-column connections by the embedding of FRP strips into grooves made on the concrete cover. According to this technique, the tension in the connection is transferred by the Near-Surface Mounted (NSM) FRP strips. To allow the transference of compression efforts among the concrete elements, the empty spaces are filled out with grout. Small-scale specimens were developed to represent the resistant mechanisms of pined beam-to-column connection composed by elastomeric cushion and dowels. The results of bond tests conducted the decision about the adhesive type and bond length to be employed in the beam-to-column connection specimens. Each specimen was made of the assembly of a column section connected to beam sections through their respective dowels and cushions. The specimens were reinforced by embedding CFRP strips in the lateral concrete cover and filling out the spaces between beams and column. Control specimens were prepared to study the influence of the cushion and grout in the connection performance. In those models, the beam sections were laid inside the wooden forms and cast together with a precast column section with no cushions between them. Experimental static and dynamic tests were done. The tests results show that strengthened connection exhibits semi-rigid behavior and acquires flexural strength compatible to monolithic structure reinforced with FRP bars.