Road Maintenance

Highway Maintenance - Maintenance is the preservation and the keeping of each type

of roadway, roadside, structures, and facilities as nearly as possible in its original

condition as constructed or as subsequently improved the operation of highway facilities

and services to provide satisfactory and safe transportation.

Primary Objectives

1. Construction of new facilities and reconstruction of existing structures for the aim

of keeping up with the traffic demands.

2. Maintenance has its own role: by giving priority to local, rural and urban facilities

particularly the paving and rehabilitation after the construction has been

completed.

3. Maintenance is focused on the do-betterment projects. It includes grading and

paving for short alignment changes to correct steep grades or sharp curves, re-

surfacing and mulching, planting, flood and erosion control.

Inter – relation between Design, Construction Methods, and Maintenance

1. Maintenance absorb the end result of efficiency or inefficiency of design and

construction be it either by act of commission or omission.

2. Poor drainage design will mean erosion or deposition of materials that requires

costly clean-up operations.

3. Sharp ditches and steep slopes requires manual labor maintenance which is very

costly as compared to flat ditches and slopes which allows equipment to work at

a lower cost.

4. Narrow road lanes usually force the large and heavy vehicles to travel with one

set of wheels near the edge or off the pavement giving the maintenance

personnel a serious problem in the care of pavement edge and shoulders.

5. Maintenance cost is the result from poor design or construction methods.

Categories of Maintenance

• Surface Maintenance

• Shoulder and Approach Maintenance

• Roadside and Drainage Maintenance

• Bridge Maintenance

• Traffic Service

ROAD SURFACE MAINTENANCE

REHABILITATION - Is defined as total overhaul of the subject.

The primary objectives of pavement rehabilitation according to AASHTO are:

To improve the smoothness of the surface

To extend the pavement life

To improve the skid resistance of the road

To reconstruct the sections with poor foundations

To improve the drainage facilities

The deficiency in the highway system are identified by:

1. Sufficiency Ratings

2. Accident Data

3. Skid Tests

4. Maintenance Reports

5. Public Suggestions

The difference between pavement rehabilitation and maintenance

Pavement Rehabilitation

- Is an activity primarily to provide good riding and

skid resistance or to improve the structural

effectiveness of the pavement.

The FHWA defined rehabilitation as:

- “Resurfacing, restoration and rehabilitation work, restoring to the original

safe usable condition without addition to the original capacity.”

A) Resurfacing

- Is the addition of a pavement layer over the existing roadway or

bridge deck surface to provide additional capacity. The

pavement layer thickness is ¾ inch or greater.

B) Restoration and Rehabilitation Work includes:

1. Replacement of defective joints

2. Repair of spalled joints

3. Substantial pavement work

4. Reworking or strengthening of bases or subbase

5. Recycling existing materials to improve their structural

integrity

6. Adding underdrains

7. Improving shoulder

8. Removing and replacing deteriorated materials

Pavement Maintenance

As discussed, refers to actions that are corrective or preventive.

Reconstruction

Refers to the removal of existing pavement and replacing them

with a new pavement and undercourses.

Overlays

Could be either by Portland Cement of Asphalt Concrete laid on

an existing pavement.

Recycling

Means the re-use of existing pavement materials working on

either asphalt materials, portland cement or lime.

Contribute to the stabilization of costs, conservation due to

inadequate material resources and reduction of energy

requirement.

Pavement recycling is categorized into the following:

1. The type of materials to be used.

2. The procedure employed.

3. The structural benefit to be gained.

The Recycling Procedures could be as follows:

1. Surface Recycling

- Consist of reworking about the top surface of asphalt pavement

which is the most common. It is applied for the treatment of

raveling, wheel truck rutting, flushing and corrugations.

The work includes the use of heater-planer, heater scarifier,

cold planers and cold milling. The disadvantages of their

use are the presence of noise, heat and air pollution.

2. In-Place Surface and Base Recycling

- this procedure involves pulverizing all the existing pavement

followed by reshaping and compacting. Before relaying, the

materials are upgraded with lime, portland cement or

chemicals. This method is used for both asphalt and

portland cement concrete pavement. One advantage of this

method is the ability to increase the load carrying capacity

of the pavement without major changes in the grade.

3. Central Plant Recycling

- Is the removal of the material from the roadway, crushing them,

mixing in the plant then laid and compacted with conventional

equipment. Both asphalt and portland cement concrete are

reprocessed to make the aggregate materials for the stabilization of

the base course. The recycled materials when used as base, is

blended without heat with additives such as portland cement, lime

or cutback or emulsified asphalt.

For Surfacing, it is heated and then blended with new asphalt cement or recycling

agents and sometimes with new aggregates.

The advantages and disadvantages of Recycling Categories

A. Surface Recycling

Advantages:

• Reduces reflection cracking

• Promotes bond between old pavement and thin overlay.

• Provides transition between new overlay and existing gutter bridge, pavement,

etc., that is resistant to raveling (eliminates feathering).

• Reduces localized roughness

• Treats a variety of types of pavement distress (raveling, flushing, corrugations,

rutting, oxidized pavement faulting) at a reasonable cost.

• Improved skid resistance

• Minimum disruption to traffic

Disadvantages:

• Limited structural improvement

• Heater-scarification and heater planning have limited effectiveness on rough

pavement without multiple passes of equipment.

• Limited repair of severely flushed or unstable pavements.

• Some air quality problems

• Vegetation close to roadway maybe damaged.

• Mixture with maximum size aggregates greater than 1 inch cannot be treated

with some equipment.

B. In-Place Recycling

Advantages:

• Significant structural improvements

• Treats all types and degrees of pavement distress

• Reflection cracking can be eliminated

• Frost susceptibility maybe improved

• Improve ride quality

Disadvantages:

• Quality control not as good as central plant

• Traffic disruption

• Pulverization equipment repair requirement

• Cost

C. Central Plant Recycling

Advantages:

• Significant Structural Improvements

• Good Quality control

• Treats all types and degrees of pavement distress

• Reflection cracking can be eliminated

• Improved skid resistance

• Frost susceptibility maybe improved

• Geometrics can be more easily altered

• Better control if additional binder and or aggregates is used

• Improve ride quality

Disadvantages:

• Increased traffic disruption

• May have air quality problems at plant site.

ROAD SURFACE MAINTENANCE OBJECTIVES:

• Unlike construction that involves high volume of work, maintenance operations

usually involve small volume of work at separated locations.

• Maintenance requires speed performance to cause the least possible disruption

and danger to traffic.

• For gravel roads, blading and periodic reshaping or material surfacing is

necessary and inevitable.

• For surface treatments and low type bituminous pavement, maintenance could

be: patching, seal coating, remixing and relaying.

• For slick asphalt surfaces, roughening, burning or non-skid seal is required.

• For Portland Cement Concrete road, maintenance could be removal and

replacement or filling of damaged areas. Sometimes joint sealing or mud-jacking

or undersealing is relatively common maintenance work.

Maintenance and rehabilitation programs are based on different types of

collected data which includes:

1. Surface roughness

2. Surface distress

3. Surface deflection

4. Surface friction or skid resistance

SURFACE ROUGHNESS

The irregularities in the pavement surface which adversely affect the riding quality.

SURFACE DISTRESS

Any indication of unfavourable pavement performance or

signs in impending failure or any unsatisfactory

performance of a pavement short failure.

Types of Distress:

A. Fracture - which is associated with load and non-load cracking

B. Distortion - which is a permanent deformation of faulting

C. Disintegration - such as spalling, ravelling and other failure of the pavement

Fracture Distortion Disintegration

SURFACE DEFLECTION

Measurement of the changes in pavement surface level between the loaded and

unloaded segments are the basis for rehabilitation design strategies. The design

strategy is to determine the structural adequacy or the ability of the pavement to resist

traffic load without developing undesirable distress.

SURFACE FRICTION OR SKID RESISTANCE

Determined from gathered data identifying a pavement section having a low coefficient

of friction. There are equipment available to determine the skid number. It is measured

using a locked wheel trailer (ASTM Method E 274) or by the use of Yaw mode trailer

where the wheels are skewed in accordance with the direction of the travel.

EVALUATION OF THE PAVEMENT

Maintenance decisions are based from pavement condition data done on project to

project basis. From these data, it is determined which project calls for maintenance or

rehabilitation including the decision required to correct pavement deficiencies. Decisions

made on a yearly basis.

Considering the increase in length of the roadways, management on the basis

of field observation alone is becoming difficult, hence, an objective method of evaluation

was introduced such as:

1. Prioritization which project needs immediate maintenance or rehabilitation.

2. The type and kind of maintenance or rehabilitation required.

3. What strategy of maintenance or rehabilitation would be adopted now and in

the future to minimize life costs or maximize the net benefits?