Tests on Expanded Clay Aggregate Lightweight Concrete - Bending Tests of Prestressed Beams.

This study presents the results of static and dynamic bending tests on two prestressed beams, one of lightweight concrete and the other of conventional concrete. The two beams have the same dimensions and reinforcements and are subjected to the same prestressing force. The interpretation of the results allows to draw a certain number of conclusion as to the comparative behaviour of the two beams as concerns: the instaneous strains and the creep strains due to prestressing: the sag under service load in the uncracked state, then in the crack phase; the increase in strains after the fatigue test (1,000,000 pulsations between 0. 5 M//s and 1. 0 M//s); the total prestress losses after fourteen days; the value of the cracking moment and the number of cracks; the failure security related to the service moment.