This paper presents an analysis of bending behaviour of glued laminated timber (glulam) beams reinforced with carbon fibre reinforced polymer (CFRP) plates, based on finite element numerical modelling. Nonlinear 3-dimen­sional model was developed and validated by experimental tests carried out on unreinforced beams and beams reinforced with two different reinforcement arrangements. Suitable constitutive relationships for each material were utilised in the model, as well as anisotropic plasticity theory for timber in compression. Adhesive bond between CFRP plate and timber was modelled as a perfect connection. Beam failure in the model was defined by maximum stress criterion. The predicted behaviour of beams has shown good agreement with the experimental results in relation to load-deflection relationship, ultimate load, elastic stiffness and strain profile distribution. The non-linear behaviour of reinforced beams before failure was also achieved in the numerical analysis, confirming the finite element model to be accurate past the linear-elastic range. Experimentally tested reinforced beams usually failed in tensile zone after compressive plasticiza­tion of top lamination, which was also simulated in the numerical model. The results proved that the load carrying ca­pacity, stiffness and ductility of glulam beams were successfully increased by addition of CFRP plate at tension side of the section.

The idea of reinforcing glued laminated timber (glulam) beams came in response to the need to improve the mechanical properties, as well as to ensure higher reliability of this type of structural elements. This paper describes an experimental program which examines the reinforcement in flexure of glulam beams with carbon fibre reinforced plastic (CFRP) plates. Fifteen beams reinforced with CFRP at the tension side and five unreinforced control beams were instrumented and tested to failure in a four-point bending configuration. The mechanical properties of reinforced beams are compared to those of unreinforced beams with regard to the load-deflection behaviour, failure mode, ultimate load capacity, stiffness and strain distribution. The experimental results demonstrated the beneficial effect of the proposed reinforcing solution in terms of strength, stiffness and ductility.

Numerous studies have proven that timber structures can be effectively reinforced using fibre-reinforced polymer (FRP) composites. In this paper a nonlinear finite element model was developed to predict bending behaviour of glulam beams reinforced with carbon fibre reinforced polymer (CFRP) plates strategically located in the tension zone between the bottom two laminations. The developed model was validated through comparison with the results of experimental tests for both unreinforced and reinforced beams. To accurately simulate the mechanical behaviour of hybrid glulam-CFRP members, suitable constitutive relations for each material were utilised in the model. The theory of anisotropic plasticity was implemented to include plastic behaviour of timber laminations in the compression zone. The Hill's criterion for orthotropic materials was used as a condition for transition to the plastic state. The progressive damage model was introduced to effectively simulate softening behaviour of timber in tension. The FEM results have shown excellent agreement with the experimental results. Nonlinear behaviour of glulam beams internally reinforced with CFRP was achieved in the numerical analysis, demonstrating the accuracy of developed model past the linear-elastic range.

Damages or failures in timber structures have created a negative image for timber as a building material. This can raise speculations and doubts about the safety level of existing timber structures. The objective of this paper is to identify typical failure modes and their causes. Experiences from previous failure investigations are summarised. Bending failures and tension perpendicular to the grain failures are common failure modes for beams. The main type of damage affecting the integrity of cross-sections is cracking along the grain. Causes for such damages are related to overloading, frequently changing wood moisture content and tensile stresses perpendicular to the grain resulting from geometry of structural elements. In the case of failure of trusses, frames and arches dominant failure mode is instability caused by insufficient bracing. The majority of failures can be linked to design and construction errors. Manufacturing errors (wood quality, production principles and methods) only cause a small number of the failures. In order to minimise or avoid errors and thereby occurrence of failures, different recommendations are given.

Transport infrastructure is increasingly exposed to climate-related hazards such as extreme rainfall, flooding, and temperature variations, which accelerate deterioration and threaten the reliability of road and railway networks. Traditional infrastructure management approaches, largely based on historical performance and deterministic deterioration models, often do not sufficiently account for evolving climate risks. This paper seeks to analyse how infrastructure asset management and maintenance systems can contribute to strengthening the climate resilience of transport networks. The paper will discuss how climate considerations can be incorporated into existing management systems through improved data collection, vulnerability assessment, and adaptive maintenance planning. It would be argued that effective asset management and timely maintenance represent practical and cost-efficient tools for enhancing the resilience of transport infrastructure under changing climatic conditions.

Cross laminated timber (CLT) is relatively new and eco-friendly prefabricated wood product in a form of large structural panels used mostly for floors and walls. Cross-wise layer configuration enables both in- and out-of-plane resistance of CLT panels, providing significant structural flexibility. Modern structural demands, such as long-spans and heavy loads, make additional reinforcement necessary for CLT panels in bending. Improvements can be achieved by using advanced composite materials. This paper describes a design model developed to predict load-carrying capacity and bending stiffness of CLT panels reinforced with glass fibre reinforced polymer (GFRP) bars in tension zone. Model was calibrated for unreinforced CLT panels and modified to consider the effect of GFRP reinforcement with varying reinforcement percentage. Good agreement was observed between theoretical and experimental test results for reinforced CLT panels.