Performance of Carbon-Fiber-Reinforced Polymer Stirrups in Prestressed-Decked Bulb T-Beams

Abstract

Eleven decked bulb T beams were constructed, instrumented, and tested under shear loading to failure. Nine beams were reinforced and prestressed with carbon-fiber composite cable (CFCC) strands, whereas one beam was prestressed with conventional lowrelaxation steel strands and one beam was reinforced with non-prestressed CFCC strands. Half the span of each beam was reinforced with CFCC stirrups, whereas the other half was reinforced with conventional steel stirrups. Both ends of each beam were tested to evaluate the performance of CFCC stirrups versus that of steel stirrups. The investigation addressed the shear performance with respect to several shear parameters, including shear-span-to-depth ratio, stirrup spacing, prestressing force, and type of longitudinal and transverse reinforcement. All test beams failed by crushing of concrete in either the web or the top flange. No rupture of CFCC stirrups was experienced in any of the test beams. The performance of CFCC stirrups was analogous to that of steel stirrups with the exception that steel stirrups demonstrated a yield plateau before concrete failure. Beam ends with CFCC stirrups attained cracking and ultimate shear capacities similar to those attained in ends with steel stirrups. Results from the experimental investigation were compared with the theoretical values predicted using some available shear design guidelines for steel and CFCC reinforcement. In addition, modifications for current AASHTO LRFD shear design equations and its possible implementation in the ACI shear design guidelines are proposed based on the experimental results.

A Stress Measurement Method for Steel Strands Based on LC Oscillation

“…Acoustic emission (AE) [4][5][6] is also an excellent method to monitor the materials' prestressing, and it uses the characteristics of acoustic information to detect the location and size of an acoustic source. Other studies [12][13][14][15] such as the application of a new material (unbonded carbon fiber) and technologies (novel optico-acoustic and sensors on a single optical fiber) in the prestressed concrete have also made some progress.…”

Ponašanje predgotovljenih betonskih greda prednapetih pomoću CFRP užadi

“…It was concluded that FRP reinforced decked bulb T-beams could be safely applied to improve the performance and prolong the life span of bridges. Shear behaviour of prestressed decked bulb T-beams having CFCC stirrups was investigated by Grace et al [13]. The effect of shear span-to-depth ratio and transverse reinforcement type on the shear carrying capacity was studied in this research.…”

Effect of applied sustained load and severe environments on durability performance of carbon-fiber composite cables

“…The use of FRP as structural reinforcement, in turn, provides the potential advantage of lowered maintenance costs and extended service life for several types of structures, including bridge deck slabs, bridge piers and piles, abutments, tunnels, walls and other structures exposed to corrosive environments. 3–5 Over the last decade, FRP tendons have been introduced into the civil-engineering industry to overcome the corrosion problem of steel tendons in prestressing applications including bridges and parking garages. 5,6 The commercially available FRP tendons are produced from a wide variety of fibers and resins and in a broad range of shapes and sizes.…”

“…3–5 Over the last decade, FRP tendons have been introduced into the civil-engineering industry to overcome the corrosion problem of steel tendons in prestressing applications including bridges and parking garages. 5,6 The commercially available FRP tendons are produced from a wide variety of fibers and resins and in a broad range of shapes and sizes. 7 However, the ACI 8 recommended aramid and carbon fibers for prestressing tendons.…”

“…Therefore, carbon-FRP (CFRP) tendons have successfully been used as prestressing reinforcement, for a number of full-scale concrete bridges, due to its high modulus of elasticity, high resistance to alkalinity, and excellent long-term and fatigue characteristics. 1,5,10,11 The most recent bridge is the Bridge Street Bridge, the first CFRP prestressed concrete bridge built in the United States using CFRP Leadline™ tendons and carbon fiber composite cable (CFCC) strands. 1…”