Title:
Very Early Post-Tensioning of Prestressed Concrete Pavements
Author(s):
J. Scott O'Brien, Ned H. Burns, and B. Frank McCullough
Publication:
Structural Journal
Volume:
90
Issue:
6
Appears on pages(s):
658-665
Keywords:
pavements; post-tensioning; prestressed concrete; strength; structural design; Structural Research
DOI:
10.14359/4460
Date:
11/1/1993
Abstract:
In designing a post-tensioned slab on grade, the post-tensioning force must be sufficient to overcome the tensile forces due to friction between slab and subgrade, which is caused by shrinkage and temperature changes tending to crack long slabs before post-tensioning is applied. This paper presents a mathematical model developed to predict safe, very early post-tensioning forces as a function of strand spacing, anchorage area, slab thickness, and concrete strength, based on a laboratory experiment. This paper presents an account of these experiments, and an illustrative application of the findings for determining the safe post-tensioning load through a set of design aids. The design method also incorporates the concept of reliability.