Description
The load-carrying capacity of concrete pavement slabs can be significantly increased by prestressing. Prestressing induces compressive stresses in the concrete of pavement slabs. These stresses modify the structural behavior of these members and considerably improve their capacity to sustain bending deformations without cracking.
Given adequate consideration to the design of joints and the placement of reinforcement, long prestressed slabs with substantially smaller thicknesses than those of conventionally reinforced pavements carrying the same loads, can be constructed practically without cracks. Also, by capitalizing on the favorable distribution of the stresses caused by the effect of the difference in the moisture content from top to bottom across the thickness of the slab, the amount of prestressing forces required, and thus the prestressing reinforcement, may be reduced.
This report analyzes the factors influencing the design of prestressed concrete pavements and recommends methods for their layout and structural analysis.
Keywords:
Concrete Pavements; control joints; creep properties; post-tensioning; prestressed concrete; prestressing steels; shrinkage; slab-on-ground construction; structural analysis; structural design; thickness; warpage.
Table of Contents
Chapter 1--Prestressed concrete pavements
1.1--Introduction
1.2--Definitions
1.3--Prestressed pavement capabilities
1.4--Historical background
Chapter 2--Time-dependent deformations and restraint stresses in
prestressed pavements
2.1--Seasonal length changes of prestressed slabs
2.2--Annual thermal-length change cycle in different
pavements--Example
2.3--Noncyclic length changes from shrinkage and prestress
plus creep
2.4--Evenly distributed restraints
2.5--Flexural restraints to deformation gradients through the
thickness of pavements
2.6--Deformations and restraints of warping
2.7--Prestress distribution on pavement sections
Chapter 3--Pavements prestressed with post-tensioned steel
3.1--Introduction
3.2--Double-joint construction
3.3--Single-joint construction
3.4--Application of prestress
3.5--Joint widths and details
Chapter 4--Critical stress combinations
4.1--Traffic-load stresses in prestressed pavements
4.2--Critical traffic-load locations
4.3--Environmental stresses for critical combinations
4.4--Pavement thickness
4.5--Highway traffic-load stresses
4.6--Airport traffic-load stresses
4.7--Allowable stress combinations in prestressed
pavements
Chapter 5--Design of prestressed concrete pavement
5.1--Design procedure
5.2--Design example for highways
5.3--Design example for airports
Chapter 6--Summary and further research needs
6.1--Summary
6.2--Recommendations for further research
Chapter 7--References