92-0031 Evaluation of Seismic Retrofit of Reinforced Concrete Frame Structures: Part II: Experimental Performance and Analytical Study of a Retrofitted Structural Model J.M.Bracci, A.M.Reinhorn, J.B.Mander 1992 University at Buffalo 202 PB93-198315 20 This report is Part II of a two part series on the evaluation of seismic retrofit methods for concrete frame structures. It deals with the behavior of the entire structural system when several retrofit techniques are applied to individual components. An analytical and an experimental study was done on a scaled model of a structure and several retrofit techniques were evaluated. Part 1 describes the evaluation of individual components retrofitted and tested with cyclic loading, that provided the base for modeling of the entire structure presented in this report. In this report the evaluation of three retrofit techniques, i.e., concrete jacketing method, masonry jacketing method, and partial frame masonry infill, is presented based on an analytical study of retrofitting a typical lightly reinforced frame designed according to ACI 318-89 only for gravity loads (1.4D + 1.7L). The jacketing technique is further evaluated based on an experimental and analytical study using a 1:3 scale structural model subjected to simulated earthquake motion supplied by the seismic simulator (shaking table) at the State University of New York at Buffalo. The (jacketing) technique was applied only to selective portions of the structure, and it achieved the limited improvement of strength and damage control as required in moderate seismicity areas and as anticipated. This selected retrofit required only minimal structural interference and may prove to be economically attractive. The analytical modeling, based on component information (obtained from the study presented in Part I of this report series), shows that the overall response of retrofitted structures can be adequately estimated, if good information is available for the components. Reinforced Concrete Frames, Concrete Jacketing, Gravity Load Design, Beam Column Joints, Retrofitting, Masonry Jacketing, Local Member Damage, Added Slab Fillets, Shaking Table Tests, Scale Model Tests, Global Failure Mechanisms, Masonry Infill, and Strong Column Weak Beams.