This study investigates the mechanical behaviour of timber–concrete composite (TCC) floor members with an innovative adhesive connection reinforced by granite chips, glass fibre yarn net in the epoxy adhesive layer, and polypropylene (PP) fibres in the concrete layer. Laboratory tests involved three groups of specimens subjected to three-point bending over a span of 500 mm with specimen lengths of 550 mm. Group A specimens exhibited crack initiation at approximately 8 kN and partial disintegration at an average load of 11.17 kN, with maximum vertical displacements ranging from 1.7 to 2.5 mm at 8 kN load, increasing rapidly to 4.3 to 5 mm post-cracking. The addition of reinforcing fibres decreased the brittleness of the adhesive connection and improved load-bearing capacity. Finite element modeling using the newly developed Verisim4D software (2025 v 0.6) and analytical micromechanics approaches demonstrated satisfactory accuracy in predicting the composite behavior. This research highlights the potential of reinforcing the adhesive layer and concrete with fibres to enhance the ductility and durability of TCC members under flexural loading.

The present study investigates the shear behaviour of screw-glued and mechanical flange-to-web connections intended for cross-laminated timber (CLT) ribbed panels, with the aim of improving composite behaviour and enhancing the structural performance of long-span timber floor and roof systems. Fifteen CLT-glue laminated timber (GLT) specimens were divided into five groups. One group incorporated SHARP501200 (SHARP) serrated steel plates, while four groups used screw-glued connections manufactured with LOCTITE HB (HB) or LOCTITE HB XE (HB XE) polyurethane (PUR) adhesive used in CLT manufacturing. For the adhesive groups, the screws were installed either from the CLT-flange side or from the GLT-web side to evaluate the influence of the assembly configuration. The specimens were subjected to monotonic quasi-static loading, and the resulting load–slip and load–displacement relationships were evaluated in terms of peak resistance, initial stiffness, post-peak response, and failure mode. The mechanically connected specimens achieved an average maximum load of 39.57 kN, whereas the screw-glued groups ranged from 141.20 kN to 198.90 kN. Installing the screws from the GLT-web side increased the average load-bearing capacity. The screw-glued connections exhibited high initial stiffness and predominantly timber-related failure, while the mechanical connection showed lower resistance and a more gradual post-peak response. Nonlinear finite element models were developed in Verisim4D (V2026), in which the CLT–GLT interfaces were represented by cohesive-zone contact elements governed by a tri-linear shear stress–slip law, consistent with the shear-dominated (Mode II) failure mode observed experimentally for both joint types. The results obtained provide design-relevant parameters and modelling strategies for optimising CLT ribbed panel joints in ultimate and serviceability states, thereby contributing to the development of efficient and environmentally sustainable multi-storey timber structures.

This study presents a novel design method for determining the tensile load-bearing capacity of a rivet nut connection with an aluminium alloy profile. The method, developed based on the requirements of standards LVS EN 1993-1-8:2025, LVS EN 1999-1-1:2023, and LVS EN 1999-1-4:2023, incorporates checks on the aluminium profile web’s shear strength, rivet and rivet nut capacities, thread strength, and profile web buckling. Twenty-five laboratory specimens across five groups—with web thicknesses ranging from 2 mm to 5 mm and utilising rivet nuts made of AISI 303 1.4305 stainless steel and AW 5052 H32 aluminium alloy—were tested. The aluminium profiles were grade AW 6060 T66. Results show that using stainless steel rivet nuts increased the elastic-stage load-carrying capacity (Fp_0.2) by 18.33% and the ultimate load capacity (Fm) by 15.89% compared to aluminium alloy nuts. The proposed design algorithm, validated by experimental tests and finite element method (FEM) analyses using Dlubal RFEM 6 (v. 4), predicts tensile resistance within a 10% accuracy. The study identifies pull-out of the aluminium profile wall as a critical failure mechanism, emphasising its inclusion to avoid overestimating connection capacity. This method provides a practical and reliable design tool for tensile load-bearing rivet nut connections in aluminium structural systems.