Highway Maintenance & Rehabilitation Dr. TALEB M. AL-ROUSAN

Highway Maintenance Definitions Maintenance: Is the routine work performed to keep a pavement, under normal conditions of traffic and normal forces of nature, as nearly as possible in its as constructed condition. Maintenance: The function of preserving, repairing, and restoring a highway and keeping it in condition for safe, convenient, and economical use.

Highway Maintenance It includes both physical maintenance activities such as sealing, patching, filling joints, and so forth and traffic service activities including painting pavement markings, removing snow, ice, and litter. Rehabilitation: restoring or betterment of roadway such as resurfacing.

Highway Maintenance Programs Are designed to offset the effects of weather, vandalism, vegetation growth, and traffic wear and damage, as well as deterioration due to the effects of aging, material failures, and design and construction faults.

Why Maintenance is Necessary All Pavements require maintenance. Stresses producing minor effects are constantly working in all pavements. Stresses are: Change in temperature and moisture; Traffic; Small movements in underlying or adjacent earth. Distresses are visible evidence of pavement wear (i.e. they are the end result of the wear process which begins when construction ends). Water lines and other utilities are major area of pavement maintenance.

Pavement Condition Life Cycle

Importance & Challenge of Highway Maintenance Protect investments made in highways. Economic & safety of public road system. Challenges: increased roads (additional mileage of travel), vehicle sizes, and traffic. Traveling public expect higher level of maintenance. Size of maintenance budget.

Maintenance Management Purpose: to capture information about maintenance activities performed & resources expanded. Maintenance management systems do not manage programs, reduce cost or improve performance, rather they provide maintenance engineers with the information and analytical tools needed to allow them to do so.

Maintenance Management Cont. Elements of maintenance management programs: Development of an annual work program (defining activities, quantities, establish performance standards, road inventory & inspection, estimate size of the work program). Budgeting & allocating resources (labor, equipment, Materials). Work authorization & control (various administration levels). Scheduling (balance of workload throughout the year). Performance evaluation (work progress & productivity). Fiscal control (monitor status of expenditures yearly).

Maintenance Operations Road surfaces Shoulders & approaches. Roadsides Bridges, tunnels, & drainage structures. Traffic controls & safety devices. Control of snow & ice.

Maintenance of Road Surfaces Aggregate road surfaces Failures due to: improper drainage, poorly mixed materials, inadequate foundation. Repairs: Patching Blading Scarifying & resurfacing (when areas to be patched are numerous). Stabilization. Bituminous surface treatment

Maintenance of Road Surfaces Cont. Bituminous surfaces Failures due to: weathering, failure of base or subgrade due to material quality or compaction or improper drainage. Repairs: Patching Paint patching Scarifying Resealing. Non skid surface treatment

Maintenance of Road Surfaces Cont. PCC surfaces Repairs: Filling & sealing of joints & cracks Repairing spalled, scaled, & map cracked areas. Patching areas where failure has occurred. Repairing areas damaged by settlement & pumping. Treating buckled pavements.

Maintenance of Shoulders & Approaches Well graded gravel shoulder : blading to proper slope and filling ruts or worn out materials. Turf shoulders: filling holes & ruts, blading, seeding, mow & clean shoulders (weed control). Approaches: include public side roads, private driveways, ramps, speed change lanes, & turnouts. Approach maintenance is similar to shoulder maintenance + extra efforts to maintain potholes, ruts, and other types of deterioration.

Maintenance of Roadsides Roadside: include area between traveled surface & the limit of the right-of-way (medians, roadside parks, right-of-way fences, picnic tables, ..etc. Vegetation management & control (include mowing, weed eradication & control, seeding, planting vegetation, & care of trees & shrubs). Mowing is done to provide sight distance, improve drainage, reduce fire hazards, & improve appearance of the roadway. Seeding & planting vegetation are important for prevention of erosion. Maintenance of rest areas. Litter control.

Maintenance of Bridges, Tunnels, & Drainage Structures Bridges: Maintenance is needed to minimize deterioration or repair damage caused by accidents, floods, or other unforeseen events. Steel bridges: cleaned & painted to prevent erosion. Concrete bridge decks deterioration: Corrosion of reinforcement bars due to penetration of water & deicing salts or chemicals. Bridge decks with minor deterioration: patch with special concrete. Bridge decks with major deterioration: Overlay or remove & construct

Maintenance of Bridges, Tunnels, & Drainage Structures Special attention areas: Supports (check for decays). Tunnel walls & ceilings (check for leaks). Portals (free from loose rocks). Lighting (for visibility) Ventilation Drainage structures Should be kept in good working conditions. Surface drainage, ditches, & culverts.

Maintenance of Traffic Control & Safety Devices Guardrails, barriers, impact attenuators, pedestrian overpasses & underpasses, fence to restrict access of pedestrians & animals. Safety devices should be frequently & systematically inspected & repaired.

Control of Snow & Ice Measures taken for preparing for snow removal are: Necessary equipments (large trucks, snow plows, power graders. Stockpiling of ice-control chemicals. Placing of snow fences, snow guides. Organization arrangements

Pavement Rehabilitation Proper maintenance extend pavement life. However, best-maintained pavements will deteriorate with time and will need rehabilitation. Conventional rehabilitation: Reconstruct with all new material Patch & overlay with new wearing surface. Due to high construction cost, new methods of rehabilitation raised: Pavement Milling (See table 21.4) Pavement Recycling

Pavement Recycling Involves the following: Remove existing pavement fully or partially. Reduce reclaimed material to suitable size. Blending reclaimed materials with virgin aggregate & liquid asphalt. Relaying the material as base, binder, or surface course Advantages of Hot mix Recycling: Economy Conservation of national resources. Improvement of the structural strength of the pavement with little or no change in thickness. Correction of existing deficiencies in the pavement mix.