Flexural strength of precast beams completed with cast in situ concrete

The results of an experimental test on a beam built in two phases are described. The beam is made of two concretes, cast at different times and with different strengths. The aim of the experimentation is to study the effect of the construction phases on the stress/strain state and on the ultimate beam capacity. In particular, the flexural strength after the long-term service loadings has been investigated. The beam has been monitored for about two months under service loads and finally loaded up to failure. A loading history characteristic of that followed during the construction phases has been prescribed. The experimental behaviour of the beam has been compared with numerical results obtained from simplified and sectional fibre models, and the effect of the construction phases has been investigated.