International Concrete Abstracts Portal

This volume contains 72 papers from the 10th International Symposium held in Tampa, FL. The papers address internally reinforced members, strengthening of columns, material characterization, bond, emerging fiber-reinforced polymer (FRP) systems, shear strengthening, fatigue and anchorage systems, masonry, extreme events, applications, durability, and strengthening. The papers emphasize the experimental, analytical, and numerical validations of using FRP composites and are aimed at providing insights needed for improving existing guidelines. The increasing maturity and acceptance of FRP is reflected by several papers that provide background information on the recent design codes and guidelines relating to blast and seismic repair. New frontiers of FRP research are explored, addressing emergin materials, and systems and applications for extreme events, such as fires and earthquakes, which will further consolidate FRP’s preeminent position. Note: The individual papers are also available. Please click on the following link to view the papers available, or call 248.848.3800 to order. SP-275

A pedestrian bridge in Albstadt, Germany showed immense corrosion damages of the steel reinforcement. The damages were so immense that the bridge had to be torn down due to a lack of load-bearing capacity and, therefore, replaced by a new bridge. The architectural design follows a slender construction principle, thus, by using the new composite material textile reinforced concrete (TRC) a slender concrete superstructure is achieved. By using non-corrosive textiles, concrete covers can be reduced to a minimum of only some millimetres and cross-sections are minimized. The paper describes the design, structural analysis, load-bearing behavior and production processes of a 97 m (3819 in.) long TRC pedestrian bridge. The whole construction is subdivided into six prefabricated parts, each offering a maximum length of L=17.20 m (677 in.) and a maximum span of Ls=15.05 m (593 in.). The cross-section, which is a T-beam, has a height of only H=0.435 m (17 in.) resulting in a slender bridge construction with a slenderness ratio of H:Ls = 1:35.

Precast lightweight concrete panels reinforced with Glass Fiber Reinforced Polymer (GFRP) bars are an ideal candidate for adoption in the construction of bridge decks using Accelerated Bridge Construction (ABC). ACI 440.1R guidelines do not provide guidance for the use of lightweight concrete with GFRP bars. Tests have been carried out to evaluate the performance of normal weight and lightweight concrete precast panels reinforced with GFRP bars. The ultimate load capacity of the panels was compared to one-way shear capacity specified in the ACI 440.1R guidelines. The reduction factor for shear specified in the ACI 318 building code for lightweight concrete was used to modify the capacity predicted by the ACI 440.1R guidelines for sand lightweight precast concrete panels. Normal weight concrete panels achieved 1.8 to 2.2 times the ACI 440 predicted capacity and lightweight concrete panels achieved 1.6 to 1.9 times the modified ACI 440 shear capacity.

Using fabric formwork, it is possible to cast architecturally interesting, optimised structures that use up to 40% less concrete than an equivalent strength prismatic section, thereby offering significant embodied energy savings. This paper reports on the latest techniques for the design, optimisation and shape prediction of fabric formed con-crete beams before new test results of an innovative anchorage method for both steel and fibre reinforced polymer longitudinal reinforcing bars are presented. Two 2m span beams were tested and the ‘helically confined splayed bar’ was shown to provide full anchorage in both cases. The two beams both exceeded their design capacity and showed remarkably similar behaviour at the serviceability limit state, with the steel reinforced section going on to display considerable ductility. Potential areas of future development are then highlighted, with the use of woven advanced composite fabrics as participating formwork for both beam and shell elements being of particular interest.

Existence of positive post-yield stiffness and mitigation of both residual deformation and damage level are critical indices in the performance of reinforced concrete (RC) bridge frame columns to assure the quick recovery of bridge original functions after a massive earthquake. In this study, because bond between longitudinal reinforcement and concrete is a key factor controlling the performance of RC structures, effects of bond parameters on the required post-earthquake recoverability of RC bridge columns reinforced with innovative composite rebars: steel fiber composite bars (SFCBs), are studied. Results of experimentally tested columns reinforced with different products of SFCBs are firstly presented. Afterward, a computer program is employed to investigate the effect of bond parameters on the recoverability indices (post-yield stiffness, residual deformations, and damage level) of columns reinforced with steel basalt-fiber composite bars (SBFCBs). The study showed that weaked bond between SFCBs and the surrounding concrete at plastic hinge zone would play an important role in the recoverability of structures reinforced with SBFCBs, where the achieved post-yield stiffness, residual deformations, and damage level could be controlled.