Assessment of nailed connections in existing timber trusses

Nailed connections of nail-board trusses taken from three different geometrical types were examined. Eight-five specimens were taken from the trusses to evaluate load-bearing capacities. Visual assessments were applied to analyse the condition of the connections, using criteria such as cracks and nail spacing. Shear tests were carried out and the results have been connected to the results of the visual assessment. The evaluation scheme has been adopted stepwise and optimized. The objective was to provide professionals with a non-destructive method for evaluating imperfect nail connections and derive appropriate repair or maintenance measures to ensure long-term functionality. This holistic approach aims at an extension of lifetime and enablement of reuse for load-bearing structural elements. • Visual assessment scheme for categorizing irregularities in nailed connections. • Load-bearing capacity was tested experimentally on nailed connections. • Cracks and spacing influence the load-bearing capacity of the nailed connections. • A relationship between load-bearing capacity and visual assessment was established. • The evaluation scheme is intended to be extended for application using AI.