A Study of the Feasibility of Methods for Increasing the Load-Carrying Capacities of Existing Concrete Beams

摘要

The primary objective of this investigation was to determine the feasibility of increasing the load-carrying capacities of existing reinforced concrete beams by building up their cross sections with additional reinforcement adhesively bonded to their horizontal an9d/or vertical faces. Waterways Experiment Station correspondence with leading chemical companies indicated that either of several epoxy-resin systems would provide a bonding strength such that the entire built-up section would act as though it were monolithic; therefore, only two of the most highly recommended systems were tested for their bonding strengths. After the most suitable adhesive (epoxy-resin system) was determined, 14 beams (11 built-up beams with clear spans of 6 ft, and 3 built-up beams with clear spans of 12 ft), excluding the control beams, were cast and tested using additional reinforcement consisting of adhesively bonded steel strips or sheets, precast reinforced concrete panels, or prestressed concrete panels, either singly or in combination. The results of these tests indicated that additional shear and tensile reinforcement can be provided by adhesively bonding these materials or any combination of the materials to the vertical and horizontal faces of the existing members. (Author)