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SP-211 This Symposium Publication contains 16 papers presented at the 2003 ACI Spring Convention in Vancouver, BC, Canada. To date, most structural tests are based on small-scale tests to verify the accuracy of analytical models. Small-scale tests can allow the mechanics (modes) of failure to be examined carefully at a fractional cost of full-scale testing. Full-scale tests render the realistic behavior of structures; however, they require large-scale testing facilities and an enormous amount of manpower in addition to being very expensive to set up and run. Whether large or small in scale, testing of structures and structural components are deemed vital in predicting field performance. This document demonstrates the effective use of various facilities to provide the realistic behavior of concrete structures through large-scale testing.

ACI 437 provides requirements for the performance of large scale structural load tests. These include mapping and monitoring cracks, shoring, and actual application of the load in a minimum of four separate increments. Any walls or other improvements that might provide support to the element being evaluated must be cut free. Deflection is to be monitored and load deflection curves prepared for each increment, and the full load is to remain in place for a minimum of 24 hours. Straightforward as these requirements appear, they can present a daunting task for those actually conducting the test. Where reaction is available for simple tests such as for beams and girders, either hydraulic jacks or pneumatic bags can be used to supply the load. Where large horizontal areas such as floors are involved, such simplicity is often not possible and some form of physical mass must be used. In areas that are open, the load can be applied with a crane, but on the interior of structures it must often be applied by hand or with the aid of small handling equipment, which severely limits the choice of load media. Whereas load tests are usually designed by structural engineers, the actual application is performed by construction workers. In order to assure optimal performance, it is imperative that both work together during the design as well as the application. The schedule and logistics of the loading operation must be well thought out prior to the actual work. Obviously, safety of the overall operation must be assured. Consideration must be given to not only the potential failure of the element being evaluated, but damage to other portions of the structure as well. This can include overloading of other elements during movement and handling of the load media, or damage by flooding where water is used. The logistics of load tests are discussed in detail, including preloading surveys and documentation, provision of shoring and other required preparation of the test area, selection of the load media and its application, and the required monitoring and control.

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.

The seismic performance of repaired reinforced concrete framed shear walls with openings is quantitatively investigated in this study. Ten large-scale repaired framed wall specimens subjected to reversed cyclic lateral loading had been tested, and a simple prediction model was proposed to analyze the test specimens. According to the failure mechanism of the prototypes, three specimens were repaired with epoxy and the other specimens were repaired by various methods, such as enlargement of the column size, additon of wing walls adjacent to the boundary columns, jacket addition to the joints of beam-column, and use of steel bracings on the wall. The experimental results show that the maximum strength of framed shear walls repaired with epoxy is close to the prototype specimen. However, their lateral displacement obviously increases and rigidity tends to be smaller. The maximum strength and energy dissipation of most other repaired specimens are greater than those of the prototype specimens, and their cyclic resistance capacities are better than those of the prototypes.

A common connection between steel outrigger beams and reinforced concrete walls involves a shear tab welded onto a plate that is conncected to the wall through headed studs. Previous studies focused on behavior of headed studs have ignored a number of major issues, e.g., (a) cyclic behavior of studs under multiple loads was not studied, (b) the concrete around studs was not reinforced or the reinforcement did not represent what would commonly be present in wall boundary elements, and ( c) effects of cracking and yielding of reinforcement around headed studs were not included. To remedy these deficiencies and to develop seismic design guidelines for outrigger beam-wall connections, a coordinated experimental and analytical research program was conducted. Through a number of tests, involving a wall subassembly and an outrigger beam, the behavior of studs subjected to cyclic tension and constant gravity shear was examined, and a design methodology was developed to control the mode of failure. To further investigate the cyclic performance of outrigger beam-wall connections and to validate the design guidelines, two 1/4-scale walls with two outrigger beams were tested. The wall reinforcement details around the connection were selected according to the anticipated level of cracking and plastic hinge formation. The two outrigger connections were subjected to constant gravity loads and cyclic tensile forces, which were controlled as a function of the wall shear. This paper provides an overview of the experimental program, testing procedures, relevant test results, and design implications. The design methodology followed in this research resulted in connections that could develop and exceed the design forces despite extensive cracking and yielding of wall reinforcement around the headed studs. Presence of heavily confined wall boundary elements around headed studs increases the capacity. A simple method to account for strengthening effects of boundary elements was develped. This model could accurately assess the expected mode of failure and capacity of outrigger beam-wall connections. Test results indicate that the outrigger beam transfers the majority of diaphragm forces directly to the core wall, and participation of floor slab toward transferring the loads to the core wall is negligible. Therefore, floor diaphragm-wall connections can be based on simplle details, and designed to resist only gravity loads.