1. 0 Introduction
Full-depth repair (FDR) is a concrete pavement restoration (CPR) technique that can be used to restore the structural integrity and rideability to concrete pavements having certain types of distresses. It involves making lane-width, full-depth saw cuts to remove the deteriorated concrete down to the base, repairing the disturbed base, installing load-transfer devices, and refilling the excavated area with new concrete. It is an effective, permanent treatment to repair pavement distresses particularly those that occur at or near joints and cracks. By removing and replacing isolated areas of deterioration, full-depth repairs may delay or stop further deterioration and restore the pavement close to its original condition. The distresses that can be addressed using full-depth repairs include transverse cracking, corner breaks, longitudinal cracking, deteriorated joints, D-Cracking, blowups, and punchouts. Table 1 provides the type and severity of distress that requires full-depth repair.
Table 1. General distress criteria for full-depth repair.
|DISTRESS TYPE||MINIMUM SEVERITY LEVEL REQUIRED FOR FULL-DEPTH REPAIR|
|Jointed Plain & Jointed Reinforced|
Concrete (JPC & JRC) Pavement
|Deterioration Adjacent to Existing Repair||Medium|
|Joint Deterioration||Medium (with faulting 6mm (0.25in))|
|Transverse Cracking||Medium (with faulting 6mm (0.25in))|
|Longitudinal Cracking||High (with faulting 12mm (0.5in))|
|Continuously Reinforced Concrete (CRC) Pavement|| |
|Punchout||Medium (with faulting 6mm (0.25in))|
|Transverse Cracking (Steel Rupture)||Medium (with faulting 6mm (0.25in))|
|Construction Joint Distress||Medium|
|Longitudinal Cracking||High (with faulting 12 mm (0.5in))|
With good design and construction practices, full-depth repairs should perform for as long as the surrounding concrete slabs. The following factors require careful consideration for successful implementation of full-depth repairs:
- Joint design, including load transfer.
- Selection of repair locations and boundaries
- Material selection
- Preparation of repair area
- Concrete placement and finishing
- Joint sealing
- Curing and opening to traffic
This document presents guidelines on how to consider these factors in the design and construction of full-depth repairs to achieve an effective long-term performance. While efforts have been made to make this guide as current as possible, highway agencies and contractors are continually seeking improved procedures and state-of-the-art equipment, such as better and quicker ways to saw and remove concrete. If more cost-effective methods are discovered they should be used as long as they are approved by the highway agency or department in charge of the project.