Repair techniques used in two existing collar beam trusses: experimental results of full size scale tests

Abstract

Structural strengthening and repair of old timber structures may be necessary due to new needs of use or due to the past history of the structure. In both cases, a thorough understanding of the present structure must be available in order to ascertain the best form of intervention. Depending on the performance and social parameters, some intervention solutions may be more adequate than others. In this work, two collar beam trusses were studied regarding their performance on full scale laboratory tests. The trusses were tested with their original conditions and after different interventions. The interventions consisted on the strengthening of the support region, local repairs using timber elements and screwed metal plates and finally on a global intervention with post-tensioned steel cables. The strengthening of the support region allowed to obtain a higher load level, while the local retrofitting of elements allowed to regain at least 80% of the original load level. The global intervention also allowed a recovery of more than 80%.