Aproximación a las pérdidas de pretensado en viguetas de cemento aluminoso

Losses approximation of alumina concrete pre-stressed small beams

The alumina concrete is largely known by properties as sulphates and/or seawater resistance, as well as its quick hardening. Specifically the last, was the one which contributed to the alumina concrete use in prefabricated elements (the resistance of Portland concrete at 30 days is reached by alumina concrete in only a couple of days). Although in determined environmental conditions damage phenomena are produced as is described further on. The delay in the prohibition on the use of alumina concrete pre-stressed small beams brought about is application as resistant element in slab floor, mainly in the 50?s (1947-1965). The reology of alumina concrete arise us a question: are the pre-stressed losses greater after the transformation of aluminates and the increase of porosity? To evaluate service limit state behaviour is necessary to test the small beams to define the current conditions of security in buildings of 35 to 50 years old. In 1995 it motivated an investigation about pre-stressed losses in alumina concrete prestressed small beams for the CIRIT (1). It is considered interesting to inform about the results on the pre-stressed losses and some conclusions resulted from.