See FHWA’s CRCP Design and Construction Guidelines for the references included in this page. A new, more comprehensive FHWA CRCP Design, Construction, Maintenance and Rehabilitation manual is currently under development and this page will be updated upon its release in the spring of 2016.
Field studies have found that transverse crack locations often coincide with the location of the transverse steel, particularly when the steel is placed in two layers. Although transverse steel can be omitted, all States that actively build CRCP use transverse steel. When used, transverse steel serves to:
- Support and maintain the specified spacing of longitudinal bars in position. Usually, longitudinal bars are tied or clipped to transverse steel at specified locations.
- Act as tiebars across longitudinal joints in lieu of conventional tiebars (although this is not often done, as transverse steel may terminate prior to reaching the longitudinal joint and a typical tiebar is used across the joint).
- Hold longitudinal cracks closed tightly to mitigate punchouts from forming.
Causes of uncontrolled longitudinal cracking include late sawing, shallow sawing, improperly installed joint inserts, or a swelling subbase or subgrade.
Bar Size and Quantity
Transverse steel reinforcement should be #4, #5, or #6 Grade 60 (#13, #16, or #19 Grade 420) deformed bars meeting the same specifications as the longitudinal reinforcement and normally spaced at standard increments of 12, 24, 36 or 48-in (0.3, 0.6, 0.9, or 1.2 m).
Transverse bars that overlap into the adjacent lane width can be staggered to function as tiebars across the longitudinal joint at a closer spacing along the middle of the paving width. For example, transverse bars spaced at 2 ft (1.2 m) and staggered in adjacent lanes would overlap the center joint by one-half the normal tiebar length and result in effective tiebar spacing of 2 ft (0.6 m),