Reinforcing struts and ties in concrete continuous deep beams

Abstract

This work proposed reinforced concrete two-span continuous deep beams by replacing the well-known conventional reinforcement by reinforcing struts and ties only and omitting the concrete where the struts and ties do not pass through. The strut and tie modelling recommended by ACI 318M-14 was adopted herein. The struts and ties were reinforced as compressive and tensile members, respectively. Twelve specimens, which were divided into four groups, were cast and tested. In every group, the first specimen was a conventionally reinforced reference beam, the second specimen was a specimen in which only the stress paths of the struts and ties were reinforced, and the third specimen was the proposed frame. The strut-tie angle, specimen width and loading type were taken into consideration as main parameters. Generally, the proposals gave less load capacity than the reference specimens, but they remained higher than the design load. In addition, the proposed specimens significantly reduced the weight.