Experimental Evaluation on Nail-Laminated Timber (NLT)—Steel Fiber-Reinforced Concrete Composite Beams with Notch Connections

In North America, timber–concrete composite (TCC) floor system is gaining increasing interest in recent years thanks to their superior structural performance and low self-weight. Notched connections are a feasible and economical shear connecting solution for panel-type TCC floors. However, the concrete layer is prone to cracking under bending due to stress concentration around notches, which could lead to a brittle failure pattern and a decrease in the load-carrying capacity of the TCC floors. To address this issue, in this study, five groups of nail-laminated timber (NLT)–concrete composite beams were fabricated with varying notch depth, number and locations of notches, and ratios of thickness. The concrete layer was reinforced with steel fibers as a potential solution to mitigate the formation of cracks in the notches. Three-point bending tests were conducted to examine their bending performance. The results showed that the bending capacity of specimens is highly related to the ratio of the thickness and the number of notches so that the load-bearing capacity and stiffness of group 5 with the thickness ratio of 1:1 increased 34.6% and 49.4%, respectively, in comparison to reference group.