The construction of submerged or partially submerged pile caps often requires the use of a cast-in-place unreinforced slab referred to as a seal slab. This slab is cast underwater around piling and inside sheet pile walls to form the bottom of a cofferdam and withstand upward hydrostatic pressure. As the seal slab is only used for a relatively short period of time during placement of the reinforcing steel and concreting, its design has received little attention in refinement tending toward conservatism. Therein, the magnitude of available bond strength between the seal slab and piling to resist the uplift pressure has been poorly quantified and largely underutilized. This paper presents experimental results from 32 full-scale tests conducted to define the interface bond between cast-in-place concrete seal slabs and piling (sixteen 356 mm square prestressed concrete piles and sixteen 356 mm deep steel H-piles). Three different concrete placement environments--dry, fresh water, and bentonite slurry--were evaluated using the dry environment (where no fluid had to be displaced by the concrete) as the control. The effective seal slab thickness was varied between 0.5d and 2d, where d was either the width or depth of the pile section. Both "soil-caked" and normal, clean pile surfaces were investigated. Additionally, four of the sixteen concrete piles were cast with embedded gages located at the top, middle and bottom of the interface region to define the shear distribution. The study showed that: (1) significant bond stresses developed even for the worst placement environment, and (2) the entire embedded surface area should not be used in calculating the pile-to-seal slab bond capacity. Current design values in the Florida Department of Transportation specifications reflect the findings of this study.

This paper reports on the experimentally and analytically observed behavior of unbounded post-tensioned precast concrete walls under static monotonic and cyclic lateral loads. Results show that the limit states that characterize that lateral load behavior of the walls occur as anticipated in the design of the walls and at force and drift levels predicted by the analytical model, except that the experimentally observed drift capacity exceeds the drift capacity predicted by the analytical model. Cyclic lateral load results how that unbonded post-tensioned precast walls can undergo significant nonlinear lateral drift without significant damage, and can maintain their ability to self-center, thus eliminating residual lateral drift.

This paper explores both flexural and shear behavior of carbon fiber-reinforced polymer (CFRP) strengthened reinforced concrete (RC) beams. For flexural strengthening of RC beams, a total of ten large-scale beams were tested to failure under monotonic and cyclic loads. The beams were originally designed as wither under-reinforced or almost over-reinforced concrete beams. The present experimental results show that externally bonded CFRP strips to the tension face of the beam is an effective technique for repair and retrofit of RC beams under various loads. This study also shows that ductility of CFRP strengthened beams, in particular for a shorter beam, is adequate if the beam is properly designed and the CFRP strips are properly anchored. Five RC beams without shear reinforcement were also cast for studying shear strengthening of RC beams. Results of test demonstrate the feasibility of using externally applied, epoxy-bonded CFRP system to restore or increase the shear capacity of RC beams. The CFRP system can significantly increase the serviceability, ductility, and ultimate shear strength of a concrete beam, thus restoring beam shear strength using CFRP is also a highly effective technique. An analysis and design method for shear strengthening of externally bonded CFRP has been proposed as well.

The pier supporting Canada Place Cruise Terminal in Vancouver, British Columbia was constructed in the 1920s. Repairs and upgrading of the reinforced concrete structure were completed in the early 1980s for the 1986 World Expo, to provide hotel and convention centre facilities and a terminal for cruise ships. Since 2000, the Port of Vancouver has undertaken major renovations and expansion to increase the capacity of the facility and meet demands of the expanding cruise ship market. The extension to the existing pier added a third berth and provided additional passenger handling facilities. The expansion required the aprons of the original deck to carry wheel and outrigger pad loads in excess of load ratings previously in use. In the absence of detailed drawings, design data and material specifications to allow assessmetn of the load carrying capacity of the original structure, full scale structural load tests were performed in accordance with Canadian Standards Association CAN/CSA-A23.3 procedures. All thirteen tests were successful, confirming adequacy of the structure to carry the new loads. This paper presents the structural parameters, methodology and results of the test load programme.

Door or window openngs in masonry infill panels can reduce the lateral strength and stiffness on infill-frame systems. In an effort to study these effects, a series of tests were conducted on half-scale test structures consisting each of three stories and three bays. Infill panels of the control structure were solid with no openings while panels of the second structue were perforated with window and door openings of varying size and location. The test structures were designed to replicate typical building practice of the early 1950's with little or no seismic detailing of frame reinforcement. The test structures were subjected to cyclic in-plane lateral forces to study their strength and deformation capacity under seismic excitation. The cyclic loading was chosen to apply displacemet demands on the structures, representative of those that are expected to occur during strong earthquake motions. Test results discussed in this paper are presented in terms of observed changes in strength, stiffness and deformation capacity of both test structures. Damage patterns and propagation of cracks in the concrete frame and masonry infill during loading are illustrated and discussed in terms of measured histories of force and deflection. Experimental results supported by analytical studies are used to estimate overall reductions in strent, deformation capacity and stiffness due to the presence of openings in the panels.