Highway Drainage

&

Maintenance

by

Haryati yaacob(fka, utm)

Highway Drainage

&

Maintenance

Highway Drainage System

Highway Maintenance

Pavement Rehabilitation

Visual Assessment of Flexible

Pavement Surface Conditions

Highway Drainage System

Adequate & proper road drainage is VERY, VERY, VERY IMPORTANT! Both for the safety of road users and pavement construction and maintenance

1. User safety – accumulated water caused hydroplaning, splash and spray

2. Pavement - reduce sub-grade strength, hydraulic pressure from passing traffic, binder stripping, slope stability

Two types of drainage:

1. Sub-surface drainage – cut/fill area, high water table

2. Surface drainage – rain, snow, run-off water

Surface Drainage System

Road surface need to be free of standing water to ensure safety

To intercept surface and watershed run-off into designed channel for discharge into river or natural waterways

Types of surface drainage system:

1. Transverse slope/crown – facilitate removal of surface water

2. Longitudinal slope – optional, help expedite water flow

3. Interceptor drain – at top of cut area to prevent water from flowing onto pavement, erosion, discharge into paved spillway/outfall

4. Side drain – alongside of highway to collect water from pavement surface, subsurface and ROW

5. Curb,Gutter and Scupper drain – drainage, embankment erosion, and encroachment (urban)

6. Culvert – under pavement, carry water across road

7. Bridge – across river or waterway, part of a road

Crowned Roadways

Road surface normally cambered or superelevated to

facilitate the removal of surface water from the road

surface

Side Drain

alongside of highway to collect water from pavement surface, subsurface and ROW

Berm/Interceptor Drain

at top of cut area to prevent water from flowing onto pavement, erosion, discharge into paved

spillway/outfall

Toe Drain

To collect water that has fallen on the batters of embankment to the point of disposal.

Cascade Drains/ chutes/spillway

an open or close channels to carry water down

the cut or embankment slopes.

Curb and gutter

Curb & Gutter

Culvert

under pavement, carry water across road

Culvert

Bridge

Koror-Babeldoub (1970-1996)

Sub-surface Drainage System

Provided within the pavement to lower the water table, intercept seepage from cut or sidehill, and drain out seepage water from pavement structure

If inadequate – premature destruction of pavement (high pore pressure, frost action), slope failure (increase stress, reduce shear strength)

Usually installed on expressway and trunk road

Three major sources of underground water:

1. Natural ground water (WT) – seasonal

2. Capillary action – move upward tru underlying soil strata, particle size dependent

3. Seepage – permeated tru slope, pavement, road shoulder

Source of ground water

Water table

Seepage from higher ground

Road shoulder

Subgrade

Road pavemen

t

Seepage from road shoulder

Capillary rise

Through permeable surface

Water table fluctuation

Longitudinal drain

– filtered perforated pipe along road shoulder - Water table < 1m beneath the formation level

transverse drain

– if longitudinal not adequate

Interceptor Drain/Pipe

A subsoil drain installed at the toe of cut slope to intercept seepage

water in the cut slope from flowing down into the subgrade.

Drainage Blanket

Upward movement by capillary rise can be controlled by providing a layer

of high coefficient of permeability beneath or between road layers to

transport water to the roadside drains.

Maintenance

Pavement maintenance is required to keep road network in

satisfactory conditions to ensure safety and low road user

costs

Consist of (component based):

1. Resurface and patching

2. Shoulder maintenance and grass cutting

3. Repair and stabilized slope

4. Clean, repair, reconstruct culvert, bridge, and drains

5. Maintenance of road furniture and markings

Does not includes widening and structural strengthening

Maintenance

Maintenance activities (frequency based):

1. Routine – carried out at least once a year, usually small scale/simple, can be carried out on a regular basis (grass cutting, patching, crack sealing, shoulder re grading, drainage, maintenance of road furniture)

2. Periodic – carried after once in a few years, normally large scale, require specialized equipment and skilled manpower, costly and need proper identification and planning (preventive maintenance work, pavement strengthening, resurface )

3. Emergency works- beyond control , need to be dealt without delay (landslides, embankment failure, collapse of bridge)

Routine and periodic maintenance needed to maintain at acceptable safety level and to avoid costly repair

Maintenance - Patch

Maintenance - Drain

Maintenance - Road Marking

Maintenance – Furniture, Landscape

Maintenance - Slope Failure

Maintenance - Slope

Maintenance - Culvert

Maintenance - Bridge

Maintenance - Other

Pavement Rehabilitation

Rehabilitation carried out when routine and periodic

maintenance are no longer adequate and traffic

growth demands for strengthening/widening or

improvement

Various techniques, selection depends heavily on

engineering judgment but other factors such as

cost, construction feasibility and effect on road

users should be considered as well.

Rehabilitation methods:

1. Restoration

2. Resurfacing

3. Recycling

4. Reconstruction

1. Restoration

When distress limitted to surfacing , such as cracking and polishing.

Restoration will – repair existing distress, reduces roughness rate and slow down pavement deterioration.

Restoration - Rejuvenating

Rejuvenators is a spray applied liquid asphalt restorationproduct that actually penetrates the asphalt with acombination of bitumen and solvents.

restores the flexibility and appearance to new condition.

recommended for asphalt that has not been sealed previously, and area of moderate to heavy traffic.

have pavement preservation benefits

A rejuvenator should not be applied to a pavement having an excess of binder on the surface.

The amount of air void in the HMA being rejuvenated should be at least 5 percent to ensure proper penetration of the rejuvenator into the pavement.

Rejuvenators should be applied in hot weather, above 20°C (70°F), so that the rejuvenator will penetrate more deeply into the asphalt pavement and will cure sooner.

Before rejuvenating After rejuvenating

Restoration-Cutting and Patching

Replacement of deteriorated asphalt surface with the new bituminous mixture , placed and compacted to the same level with the surrounding surface.

Patching material can be just about any HMA or cold mix asphalt material as well as certain types of slurries.

• Patches can be either full-depth where they extend from the pavement surface to the subgrade ( Figure 10.12) or partial where they do not extend through the full depth of existing pavement ( Figure 10.13).

• Full-depth patches are necessary where the entire depth of pavement is distressed.

Method of patching:

1. "Scoring" or cutting the pavement beyond thedistressed area.

2. Removal of distressed pavement (debris asphalt isreturned to asphalt producer plants for recycling).

3. Base/sub-base stabilization and compaction.4. Applying "tack oil" to all existing pavement edges

bonding the new pavement to existing pavement, andproviding a seal.

5. Placement and compaction of new hot mix asphaltmaterial.

Maintenance - Patch

Good patching jobs include cutting the area around the patch, not just throwing

asphalt into the hole.

• Also known as non-structural overlay

• do not involve extensive structural design and generally contribute little to a pavement's structural capacity.

• Used to:

1. Improve ride quality.

2. Correct minor surface defects.

3. Enhance appearance.

4. Reduce road-tire noise

5. Extend pavement service life.

6. Improve safety characteristics such as skid resistance and drainage.

Restoration - Thin Bituminous Overlay

THREE common used method:

1. Surface dressing

• Bitumen emulsion sprayed onto road surface, immediately followed by single or multiple cover of chippings to the bitumen using large spreader.

• Bitumen will secure the chippings and seal old road surface, preventing ingress of water.

• Chippings will restore texture of road surfaces, preventing skidding accidents.

2. Slurry seal

• Mixture of fine aggregate, filler or emulsified bitumen that has a creamy fluid-like appearance

• Normally be placed over an existing asphalt surface which is found to be in relatively good shape.

• Able to extend the life of the existing pavement by 5 to 7

years. PHOTOS SHOW HOW SLURRY SEAL IS APPLIED

3. Thin hot mix overlay

• Hot asphalt mix of less than 40 mm thickness

• Effective for Flexible and Rigid Pavements

• Improves Life Cycle Cost

Restoration – Crack Sealing

2. Resurfacing

When pavement have severe and extensive structural

damage - structural improvement required

Most popular in Malaysia

Involved placement of fresh material – improves riding

quality, enhance structural strength

Need to properly design the overlay thickness to

achieve design life

Using thick asphalt overlay – with or w/o prior granular

overlay (pre-treatment required)

Video

3. Recycling

Use of old pavement material to correct raveling,

bleeding and improve skid resistance

Types of recycling:

1. Hot recycling – repair surface crack, road base still

sound, use heat to soften surface

2. Cold recycling – milling defected surface and reuse

with addition of stabilizer, rejuvenator or bitumen

3. Base recycling – road base fail, use stabilized old

surface material as base, lay new surfacing

Hot in Place Recycling (HIPR)

– repair surface crack, road base still

sound, use heat to soften surface

HIPR video

Cold in Place Recycling (CIPR)

– milling defected surface and reuse with

addition of binding agent (emulsion,

foamed bitumen or cement)

- Use as RB

CIPR video

Reconstruction

Removal and rebuilding of all or part of pavement

using fresh material (current practice recycle) and new

construction specification

Pavement failed severely where deterioration has

been allowed to occur w/o maintenance, or

inadequate sub-surface drainage

Types of reconstruction:

1. Hot recycling with overlay

2. Cold recycling with overlay

3. Construction/improvement of sub-surface drainage

Visual Assessment of Pavement

Surface Conditions

Assessment of pavement surface conditions used by

highway agencies to:

1. Measure the ability of pavement to continue to provide

service to public

2. Determine deficiencies and inadequacies of pavement

3. Determine remedial measures to be taken and its

fiscal needs

4. Planning and programming of pavement maintenance

and/or rehabilitation

Visual Assessment of Pavement

Surface Conditions

Types of distress in flexible pavement:

1. Cracks

2. Surface deformation

3. Surface defects

4. Patches

5. Potholes

6. Edge defects

Pavement Cracks

Cracks – fissures resulting from partial or complete fractures of the pavement surface

Variety of patterns from isolated to interconnected over entire surface

Detrimental effects of cracks:

1. Loss of water proofing

2. Loss of load spreading ability

3. Pumping and loss of fines from road base

4. Loss of riding quality

5. Loss of appearance

Pavement Cracks

Possible causes of cracks –Depression, Fatigue life of

surfacing exceeded, Age embrittlement of surfacing,

Reflection cracks from underlying layers, Shrinkage,

Poor construction joint

Probable treatments – cut and patch, reconstruction,

replace surfacing, crushed aggregate overlay, crack

sealing, improve drainage and shoulder, widen

pavement, strengthen shoulder, overlay with stiffer mix

Types of cracks – longitudinal, transverse, block,

crocodile, edge, crescent shape

Surface Deformations

Deformation takes place when surface undergo changes from its

original profile (due to traffic, environment, inadequate control

during construction)

Influences riding quality and may reflect structural inadequacies,

may lead to cracks

Possible causes – inadequate thickness, poor compaction,

unstable premix, base or sub-base, volume change, settlement,

lack of bond between bituminous layers, start-stop

Probable treatments – overlay or reconstruction, replace/recycle

with stiffer mix, base/sub-base strengthening, improve subsoil

drainage, shoulder improvement

Major types – rutting, corrugation, shoving, depression

Surface Defects

Surface defects cover loss of surfacing materials and surface micro/macro texture

Have significant influence on serviceability, safety (skid resistance and maneuverability), and riding quality. If not corrected may lead to loss of pavement structural integrity

Possible causes – excessive/lack of binder content, excessive/lack of coating, paving over flushed surface, poor adhesion between aggregate and binder, inadequate compaction, low PSV, seepage of water tru surface, adhesion of binder to vehicle tyres

Probable treatments – apply hot sand, thin bituminous overlay, use stiffer mix, mill and re-lay upper layer, replace WC, reconstruction of weak layers

Major types – bleeding, polishing, raveling, delamination

Patch & Pothole

Patch – repaired section where a portion of pavement has been removed and replaced

Extend and frequency as indicator of structural adequacy

Defects can occur within a patch or patch higher/lower than pavement surface

Pothole – bowl shape cavity in the pavement from loss of WC and BC

Produced when traffic breaches small pieces of pavement allowing water to enter > disintegrate, collected water accelerates disintegration

Possible causes – loss of surface, moisture entry tru cracks, load associated base disintegration

Probable treatments – cut and patch, base reconstruction

Edge defects

Occur along interface of pavement and shoulder, most significant

if shoulder unsealed

Detrimental effects – reduction of pavement width, loss of riding

quality and maybe loss of control, channeling water erodes

shoulder, entry of water into base

Possible causes – inadequate width/edge support, poor

alignment, edge drop-off,loss of adhesion to base, shoulder

material of low resistance to abrasion and erosion, resurface

pavement w/o resurface shoulder

Probable treatments – widening, re-alignment, strengthen and

leveled shoulder, cut and patch, replace shoulder material

Types of edge defects – edge drop-offs, edge breaks

End of SAM4814 Highway

Maaf atas segala kesilapan dan kesalahan saya, sama ada disedari atau pun tidak

Good luck with what ever you are & will be doing

See U FINAL nanti…

Feel free to drop by if U have any question… or just 1 2 chat with me…

Rehab – Thin Overlay :

slurry, dressing, hot mix

Rehab – Resurfacing

Rehab – Hot Recycling

Rehab – Cold Recycling

Rehab - Reconstruction

Rehab - Subsoil

Va - Cracks

Vaf1 - Longitudinal

Vaf1 - Transverse

Vaf1 - Block

Vaf1 - Crocodile

Vaf1 - Edge

Vaf1 - Crecsent

Va - Surface Deformation

Vaf2 - Rutting

Vaf2 - Shoving

Vaf2 - Depression

Vaf2 - Corrugation

Va - Surface Defects

Vaf3 - Polishing

Vaf3 - Bleeding

Vaf3 - Delamination

Vaf3 – Raveling/stripping

Va - Patch & Pothole

Vaf4 - Patch

Vaf5 - Pothole

Va - Edge defects

Vaf6 - Edge Drop - off

Vaf6 - Edge Breaks

Vaf6 – ???