CE 5345 Infrastructure Evaluation, Maintenance and Renewal

Topic: Concrete Pavement Rehabilitation Methods

Submitted to: Dr. Ghassan Khankarli(Ph.D., P.E., PMP)

Prepared by: Saeed Janbaz Denish Sonani Harshil Joshi Ashish Paliwal

Introduction

Well designed rigid pavement provides excellent performance for long term.

Distresses may take place in rigid pavement and rehabilitation is required to get expected useful life.

Repair/Rehabilitation requires understanding of causes and mechanics of distresses.

In rigid pavement, distresses are limited and causes are well understood.

This presentation is focused on specific repair/rehabilitation methods for these distresses.

Methods Covered

Bonded concrete overlay (by Saeed Janbaz) Diamond grinding (by Saeed Janbaz) Full depth repair (by Sonani Denish) Partial depth repair (by Sonani Denish) Dowel bar retrofit (by Harshil Joshi) Cross stitching of longitudinal cracks (by Harshil Joshi) Joint repair (by Ashish Paliwal) Thin asphaltic concrete overlay (by Ashish Paliwal)

Bonded concrete overlay

Done on continuously reinforced concrete pavement (CRCP) Good rehabilitation method for older, insufficiently designed pavements. New concrete layer is applied on old pavement. In Texas, some BCO has provided extended life of 20 years. Increase in life depends on bond strength between new and old

concretes.

Procedure for BCO

Evaluate whether the project is a good candidate for BCO. Develop adequate slab thickness and steel designs. Prepare surface of existing pavement for overlay. If needed, place steel. Place concrete and provide optimum curing.

Diamond Grinding

Removes thin layer on PCC using diamond blades. Improved technologies has made diamond grinding cost effective

rehabilitation method for PCC End product is leveled surface with longitudinal texture. Depth of DG is 0.1 to 0.25 inch. Does not effect structural capacity of pavement.

Advantages of DG on PCC

improves pavement smoothness. costs substantially less than an overlay. enhances surface friction and safety of an old concrete pavement surface. significantly reduces noise generated by tire-pavement interaction. does not affect fatigue life or material durability of the pavement. Can be accomplished during off peak hors W/O disturbing other lanes. eliminates the need for taper, which is required with overlay alternatives,

at highway entrances, exits, and at side streets does not affect overhead clearances underneath bridges or hydraulic

capacities of curbs and gutters on municipal streets.

Partial Depth Repair

Spalling causes noise problems as well as reduction of ride quality. PDR is used for restoration of upper one-third part of total slab depth. Proper identification of spall depth is important to determine limits of

repair. Most efficient way to determine spall depth is sounding test by hammer.

Procedure for PDR

Identify the area to be repaired. Remove deteriorated concrete. Clean the repair surface. Apply bonding agent. Place, finish and cure the PCC.

Full Depth Repair

Transverse cracking, punchouts and corner breaks can damage concrete throughout its depth.

FDR is used for localized damage beyond one-third portion of slab depth.

Corner breaks and slab cracking are indication of structural inadequeties that can not be repaired by PDR.

Procedure for FDR

Identify and locate the area. Remove the damaged material. Prepare the area to be repaired. Apply a bonding agent. Place, finish and cure the PCC.

Dowel Bar Retrofit

Used for JCP and PCC. Older pavements does not have dowels. With the passage of time aggregate interlock does not provide effective

load transfer. Effective load transfer b/w slabs is important for reduction in faulting

and cracks. This method is fast, effective, and economic to rehabilitate old

pavements compared to ACP overlay.

Procedure for DBR

Identify need for DBR. Cut the slots. Prepare the slots. Placing the Dowels. Backfill the slots.

Cross-Stitching Longitudinal Cracks Can only be used for longitudinal cracks, not transverse cracks. Stitching transverse cracks can cause stress build up and can cause

cracks or spalls. Longitudinal cracks does not deteriorate as quickly as transverse cracks. Deformed tie bars are inserted in to drilled holes on both side of the

cracks. Bars are coated with epoxy or grouted in to holes Distance of the bars from holes and diameter of bars depends on the

thickness of the slab.

Procedure for cross-stitching

Drilling holes at an angle so that they intersect the longitudinal crack or joint at about mid-depth.

Airblowindg the holes to remove dust and debris after drilling. Injecting epoxy into the hole, leaving some volume for the bar to

occupy the hole. Inserting the tie bar into hole. Removing excess epoxy and finish flush with the pavement

surface.

References

http://www.fhwa.com http://www.pavementinteractive.org Pavement management for airports, roads and parking lots second

edition by M.Y. Shahin, springer 2005 Modern Pavement Management by Ralph Haas, W. Ronald Husdon, John

P. Zaniewski, Krieger 1995 CE-5341 lecture notes

Thank You