The use of partial blanketed strands in design of prestressed precast beams

Abstract

Concrete is considered to be prestressed when it is subjected to a state of strain and deformation before being loaded with payloads from service stage. Efforts and deformations resulted from prestress are so established to counteract the effects produced by the transfer and service loads. Efficient design of prestressed precast beams is based on the rational use of materials: concrete and reinforcement (especially strands). Poor use of materials in design phase may result in inappropriate solutions from an economic point of view. To avoid this aspect partial blanketed strands are used. To obtain a partial blanketed strand the adhesion between it and concrete is stopped punctually, the transfer of tensions being carried out in the contact areas. In the present paper it will be illustrated the stress development on the beam resulting from the use of partial blanketed strands. To highlight these particularities the IDEA StatiCA software was used and, the results presented graphically and tabular revealed the advantages of partial blanketed strands.