Highway Maintenance and Rehabilitation PDF

**MODULE 7: Highway Maintenance and Rehabilitation** Highway Maintenance - Routine work performed to keep a pavement under normal conditions of traffic and normal forces of nature, as nearly as possible in its original condition (monitoring pavement health) - Maintenance actions help...

**MODULE 7: Highway Maintenance and Rehabilitation** Highway Maintenance - Routine work performed to keep a pavement under normal conditions of traffic and normal forces of nature, as nearly as possible in its original condition (monitoring pavement health) - Maintenance actions help slow the rate of deterioration by identifying and addressing specific pavement deficiencies that contribute to overall deterioration Maintenance Operations - Surface maintenance - Road side maintenance - Shoulder and approaches maintenance - Bridges, tunnels, and drainage structure maintenance - Traffic controls and safety devices (road signs, pavement markings, traffic signals, and road lighting) Maintenance of Road Surfaces 1. Bituminous Surfaces - failures due to weathering, failure of base or subgrade due o material quality or compaction or improper drainage - Repairs: - Patching - Scarifying - Resealing - Non skid surface treatment 2. PCC Surfaces - Repairs: - Filling and sealing of joints and cracks - Repairing spalled, scaled, and map cracked areas - Patching areas where failure has occurred - Reaping areas damaged by settlement and pumping - Treating buckled pavement 3. Maintenance of Shoulders and Approaches - Approaches include public side roads, private driveways, ramps. Speed change lanes, and turnouts - Approach maintenance is similar to main roadway maintenance 4. Maintenance of Roadsides - Roadside include area between traveled surface and the limit of the right-o-way (medians, roadside parks, ROW fences, etc.) - Vegetation management and control (include mowing, weed eradication and control, seeding, planting vegetations, and care of trees and shrubs) - Maintenance of rest areas 5. Maintenance of Bridges, Tunnels, and Drainage Structures - Bridges need to minimize deterioration or repair damage caused by accidents, floods, or other unforeseen events - Steel bridges need to be cleaned and painted to precent erosion - Concrete bridge decks may deteriorate due to the corrosion of reinforcement bars due to penetration of water and de-icing salts or chemicals - Bridge deck with minor deterioration is to be patched with special concrete - For major deterioration it is to be overlayed or removed and constructed - Tunnels (special attention areas): - Supports -- check for decays - Tunnel walls and ceilings -- check for leaks - Portals -- free from loose rocks - Lighting -- for visibility - Ventilation - Drainage Structures (following should be kept in good condition:) - Surface drainage - Ditches - Culverts - Traffic Control and Safety Devices - Guardrails, barriers, impact attenuators, pedestrian overpasses and underpasses, fence to restrict access of pedestrians and animals - Safety devices should be frequently and systematically inspected and repaired Pavement Rehabilitation - Proper maintenance extend paement life - However, the best-maintained pavements will deteriorate with time and will need rehabilitation - Conventional rehabilitation: - Reconstruct with all new materials - Patch and overlay with new wearing surface - Due to high construction cost, new methods of rehabilitation are raised: - Pavement Milling -- surface layers can be removed with a milling machine and replace with new hot-mix - Pavement Recycling -- technique where an existing degraded pavement is modified and transformed into a homogeneous structure that can support the traffic requirements