Structural behavior of fully prefabricated glubam-concrete composite beams constructed of innovative connectors

Abstract

This study focuses on developing fully prefabricated glued laminated bamboo (glubam)-concrete composite (BCC) beams constructed of the innovative ultra-high performance concrete (UHPC)-steel composite connectors. Five mid-scale prefabricated BCC beams with different connectors and concrete slabs were tested under short-term loading conditions to evaluate the flexural behavior. Particular emphasis was placed on verifying the convenience and deconstructablity of the proposed assembly structure through a secondary assembly and loading process, revealing that the prefabricated BCC has the advantage of rapid assembly construction and appreciable reusability. This assembly structure exhibits favorable bending performance under short-term loading conditions and it shows partial composite action. Reducing spacing and enhancing shear resistance of the UHPC-steel composite connector effectively improves the flexural behavior of BCC beams. In addition, casting a layer of laminated lightweight aggregate concrete with 30 mm thick on site can enhance the bending performance of the prefabricated BCC beam with effective control of the increase in its self-weight. Typical load capacity models derived from timber-concrete composite (TCC) beam were evaluated by the test results for predicting the load capacity of the prefabricated BCC structure. A comparison and evaluation were conducted on six large-scale BCC beams connected by different connectors, indicating that the proposed fully prefabricated BCC system possesses superior competitive advantages compared with existing BCC/TCC beams and it has a good application prospect in building engineering.