Equivalent surface load to the self-weight of a builder on the cantilever of a prestressed floor plate in phase of execution

This document follows the Cerib study conducted for the FFB (Report No. 2014 CERIB 3965) in which the influence of a possible deterioration of the conditions of support on the mechanical behavior of a prestressed floor plate in phase of execution was studied. This study indicates that it is necessary, in the absence of recommended precautions such as a mortar bed or a surfaced support state according to DTU 21, to support the prestressed slabs on a propping line whose axis is separated from the wall up to 30 cm.

The prestressed element is then cantilevered on the props. In this case, the execution load Qs1 = 1.5 kN/m² is not anymore representative of the point load corresponding to the passage of the builders on the cantilever, and it is necessary to define another equivalent surface load Qs1 to check the resistance of the element in this provisional phase.

This study therefore provides values of equivalent surface load Qs1 corresponding to the weight of a man of about 100 kg located in the corner of this cantilever with a variable spa ‘x’, that will be used in the design of the product in the execution stage as an additional verification.

Keywords: Concrete, Mechanical behavior, Prestressed floor plate