Fiber-reinforced polymer-reinforced concrete (FRP-RC) structures have won researchers’ attention for decades as a considerable substitute due to their superb mechanical and non-mechanical properties. Despite the promising potential of concrete structures with glass FRP and basalt FRP that were shown by previous research, there are few specifications for the seismic design of FRP-RC structures to date due to limited research data on their seismic behavior. This paper focuses on the seismic performance of concrete columns with carbon fiber-reinforced polymer (CFRP) reinforcement by finite element modeling. The effect of longitudinal reinforcement type and ratio, stirrup spacing, concrete strength and axial load ratio are included in the parametric analysis in VecTor2. Properly designed CFRP-RC columns with good confinement generally reach high load-carrying capacity and deformation level, while high axial load could induce relatively severe damage. To verify these conclusions, seven full-scale columns are under construction and will be tested under combined lateral reversed cyclic loading and constant axial loading.

This paper presents the crack monitoring of reinforced concrete beams strengthened with fiber reinforced polymer (FRP) sheets. Emphasis is placed on the development of a smart FRP bonded material that can measure the crack opening of a reinforced concrete beam strengthened by FRP. The reliability measured by a conventional digital image correlation (DIC) and by the proposed smart FRP is employed to assess the contribution of the FRP to control the crack. The monitoring process is based on a large set of experimental database consisting of 19 test beams. The effect of FRP to control the crack opening is studied depending on the steel ratio, FRP ratio and the level of damaged of RC beams when FRP is applied. The results were compared with the theoretical values of crack width and spacing predicted using the Eurocode 2 (EC2) formula, calibrated for non-strengthened RC elements. The corresponding results were compared in order to clarify the effect of external bonded FRP on the cracking behaviour of RC beams.

Three bridge barriers were tested under pseudo-static loading to assess the effectiveness of a dowelling repair technique for restoring the capacity of damaged glass fiber-reinforced polymer (GFRP) reinforced systems. Barriers were 1500 mm (59.1 in.) wide and tested with an overhang of 1500 mm (59.1 in.). One barrier was entirely reinforced with steel reinforcement with the layout and geometry common in Alberta, Canada for highway applications. A second barrier replaced all steel reinforcement with GFRP bars. The third barrier simulates repair where the barrier is damaged and needs to be replaced by removing the barrier, drilling holes, and using epoxy to dowel GFRP bars into the deck. All barriers failed by concrete splitting at the barrier/deck interface which is attributed to the complex interaction of stresses from the barrier wall and overhang. The steel reinforced barrier was strongest but had slightly lower energy dissipation than the GFRP reinforced barriers. The repaired GFRP reinforced barrier had very similar response to the baseline GFRP reinforced barrier but reached a slightly larger capacity. Previously completed finite element models showed similar general responses and failure modes but larger stiffnesses and strengths than the tests which requires further investigation.

In the last decades, the devastating effects of earthquake events in seismic prone regions increased the attention on the vulnerability of existing constructions. Masonry walls especially experienced severe damage, both considering out-of-plane and in-plane mechanisms. To increase their resistance to horizontal forces, different strengthening systems can be applied. The objective of the present work is to study the efficiency of an innovative strengthening solution, involving the use of fiber reinforced polymer (FRP) pultruded bars. An experimental campaign is presented, in which clay-brick single-leaf masonry panels are retrofitted by carbon FRP rebars, inserted into grooves cut within the masonry panel with a cementitious mortar, and CFRP sheets applied on the panel external surfaces. A total of seven direct shear tests (ST) and four diagonal compression tests (DC) were performed on unreinforced and strengthened samples. The results of the tests showed that the strengthening technique can be effective for the improvement of the shear sliding and diagonal cracking resistances, also allowing to deepen the knowledge of the principal failure mechanisms characterizing the FRP-retrofitted masonry elements.

While reinforced concrete is one of the most used construction materials, traditional reinforcement steel may cause undesirable side effects, as corrosion and the associated volume changes can lead to damages in the concrete matrix and can cause spalling, which may significantly reduce the load-bearing capacity and service life of structures. Alternative reinforcement methods, such as glass or basalt fiber reinforced polymer rebars, can serve as a viable alter-native to reduce or eliminate some of the disadvantages associated with steel reinforcement. In addition to an increased tensile strength and a reduction in weight, fiber reinforced polymer rebars also offer a high corrosion resistance among other beneficial properties. Because these materials are not fully regulated yet and the durability properties have not been conclusively determined, further research is needed to evaluate the material durability properties of FRP rebars. To determine the durability properties of GFRP and BFRP rebars in cold climates, the freeze-thaw resistance of these materials was evaluated throughout this study. Specifically, two types of materials (basalt and glass reinforced polymers) and two common rebar sizes (8 mm (#2) and 16 mm (#5) diameters) were tested. To quantify the freeze-thaw-durability, tensile tests according to ASTM D7205, transverse shear strength tests in line with ASTM D7617, and horizontal shear strength tests as specified in ASTM D4475 were conducted on numerous virgin fiber rebars and on fiber rebars that were subjected to 80 and 160 freeze-thaw cycles. While the results from the virgin materials served as benchmark values, the measurements and analysis from the aged (by freeze-thaw cycles) materials were used to quantify and determine the strength retention capacity of these bars. The results showed that a higher number of freeze-thaw cycles lead to lower strength retention for some rebar types. In addition, it was seen that rebar products respond differently to the aging process; while some material properties notably deteriorated, other material properties were insignificantly affected.