Shallow notch-screw connections, which showed potential superior slip moduli and load-carrying capacity compared with the traditional screwed connections and can be employed in the timber-concrete composite (TCC) floors were examined in this study. Eight groups of shallow notch-screw connections were designed to perform the push-out tests, in which the arrangement of screws, the heavy timber types, and the width of the shallow notch were considered. The depth of the notch was uniformly 15 mm. The vertical screws and the cross inclined screws were separately selected as the reinforcement for the shallow notch connections. The common heavy timber panels, including nail laminated timber (NLT), glulam, and cross laminated timber (CLT), were adopted. The width of the shallow notch tested included 100 and 200 mm. The experimental results showed that the shallow notch connections underwent ductile failure. The effects of testing factors on the shear strength, slip moduli, and ductility were discussed. The design proposals about the slip moduli of the shallow notches using each timber panel types were proposed, aiming to provide guidance for the application of the TCC floors with shallow notches.

This paper presents the push-out experimental results of hybrid notch-screw (HNS) connections for timber-concrete composite structures. A total of 7 groups of specimens were designed and tested. The experimental parameters included the loading constraint conditions (i.e., the test specimens were loaded either in local compression or in uniform compression), shapes of notches in the wood, screw number in notch, notch width, and the inclusion of a self-tapping screw reinforcement for timber or not. The experimental results were discussed in terms of failure modes, ultimate strength, slip moduli, and ductility. The yield strengths and ductility factors were determined based on the load-slip curves according to existing standards. The experimental results showed that both the shear timber width and the self-tapping screw reinforcement played important roles in terms of the ultimate strengths, ductility, and deformability. Rectangular notched connections with screw reinforcements displayed timber shear failure coupled with brittle failure. With the trapezoidal notch, the ductility of the connections improved, coupled with a decrease in the slip modulus. The self-tapping screw reinforcement for shear timber could greatly improve the ductility performance of the HNS connections. The slip modulus models for the connection with vertical deep notches were provided, which were in agreement with the experimental results.

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To promote the development of timber-concrete composite (TCC) structures, it is necessary to propose the assembly-type connections with high assembly efficiency and shear performances. This article presented the experimental results of the innovative steel-plate connections for TCC beams using prefabricated concrete slabs. The steel-plate connections consisted of the screws and the steel-plates. The steel-plates were partly embedded in the concrete slabs. The concrete slabs and the timber beams were connected by screws through the steel-plates. The parameters researched in this article included screw number, angle steel as the reinforcement for anchoring, and shallow notches on the timber surface to restrict the slip of the steel-plates. Experimental results were discussed in terms of failure modes, ultimate bearing capacities, and slip moduli. It was found that increasing the number of screws could lead to the obvious improvement on the ultimate bearing capacities and the slip moduli at the ultimate state; and the angle steel as the reinforcement showed the slight influence on the ultimate bearing capacities and the slip moduli. The application of the shallow notch can greatly improve the ultimate bearing capacities and the slip moduli. The calculation models for the ultimate bearing capacities and the slip moduli of the steel-plate connections with and without shallow notches were proposed, which showed good accuracy compared with the experimental results.