RBS polymer encased concrete wall part I: experimental study and theoretical provisions for flexure and shear

Royal Building Systems™ (RBS) is a patented polymer-based extruded stay-in-place formwork for low to mid-rise concrete walls. The extruded components slide and interconnect together to create formwork which when filled with concrete results in permanent, attractive, and pre-finished concrete walls that can be easily constructed in any climate. The RBS system is highly durable and resistant to decay and deterioration, non-toxic, virtually maintenance free and weather resistant. The polymer encasement provides crack control in both the vertical and horizontal directions, increases the structural capacity, and enhances the ductility of the wall under seismic conditions. This paper presents the results of an experimental investigation of the flexure and shear behaviors of such walls. In addition, theoretical provisions which quantify the contribution of polymer to structural strength enhancement are derived and compare well with the experimental results.