Long-term experimental tests on precast beams completed with cast in-situ concrete

These 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 behaviour under long-term service loadings has been deeply 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 results are given in terms of strains, deflection and curvature evolutions with time. 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. KEYWORDS: concrete, creep, precast beam, experimental test, flexural strength.