Chapter 10 - Road Maintenance (Road Defect)

ROAD DEFECTMOHD HANAFI BIN HASHIM

POLITEKNIK KOTA KINABALU

CROCODILE CRACK

Crocodile is interconnecting or interlaced cracking in a

road seal resembling the hide of a crocodile. Cell sizes canvary in size up to 300mm across, but are typically less than

150mm across.

CROCODILE CRACK

CROCODILE CRACK

CORRUGATION

corrugation are closely & regularly spaced transverse

undulations in the surface of a road,

Corrugations can occur in both sealed and unsealed

roads. They can be caused by inadequate stability of an asphalt surface or pavement or the compaction of the

base in wave form.

Crest to crest spacing is typically less than 2 metres.

CORRUGATION

CORRUGATION

CORRUGATION

CORRUGATION

DELAMINATION

Delamination is a failure mode that can occur in layered materials. With respect to roads it refers to the loss of large discrete area of the wearing course layer, usually in conjunction with a clear delineation of the wearing course from the layer below.

Possible Causes

Inadequate cleaning or inadequate tack coat before placement of upper layers.

Seepage of water through asphalt resulting in the breaking of the bond between the surface and the layer below.

A weak loose layer immediately under the wearing surface.

Adhesion of surface binder to the tyres of vehicles

DELAMINATION

DELAMINATION

DEPRESSION

In road engineering a depression is a localised

area of pavement surface that is slightly lower in

elevation than the surrounding pavement.

Depressions are most easily identifyable after rain

when they fill with water.

DEPRESSION

DEPRESSION

EDGE DROP OFF

An edge drop-off is road geometry defect where the vertical

distance from the edge of seal to the adjacent shoulder

exceeds acceptable limits.

Edge drop-offs generally occur when the road shoulder is worn, or there is inadequate strength of the pavement ay

the edge of the roadway. A significant edge drop-off can

make the transition between the road and its shoulder

challenging particularly for smaller vehicles, and this may

result in a loss of control for the vehicle.

EDGE DROP OFF

EDGE BREAK

An Edge Break is a broken or irregular edge of a road

wearing surface.

Edge breaks generally occur when the road shoulder is worn,

there is inadequate strength of the pavement at the edge if the roadway or water enters the pavement through the

shoulders. Significant edge breaks coupled with edge drops

can result in tyre damage.

EDGE BREAK

POTHOLE

A pothole is a hole in a road pavement, frequently rounded in

shape, resulting from the loss of pavement material under

traffic.

A pothole is created by the interaction between water and

traffic. Inadequate drainage alongside the road shoulder can

result in water entering underneath the pavement during

prolonged periods of rain. This weakens the pavement's subsoil

resulting in fatigue failure, or cracking, due to the flexing of the

pavement under vehicular loading.

These cracks in the pavement surface thereby provide another

entry for water and exacerbate the weakening of the

pavement's sublayers.

POTHOLE

RAVELLING

Ravelling is the progressive disintegration of a (road)

pavement surface through loss of both binder and

aggregate.

Water on the pavement is the primary cause for the loss of

the binder, while vehicular traffic gradually ravels away

the aggregate which has been loosened due to binder

loss.

RAVELLING

RAVELLING

RUTTING

Rutting is the longitudinal vertical deformation of a pavement

surface in a wheel path, measured relative to a straight edge

placed at right angles to the traffic flow and across the wheel

path, with a length/width ratio greater than 4:1.

A single instance of rutting is called a rut or wheel rut. Large ruts

can hold enough water to result in vehicles aquaplaning in wet

weather.

RUTTING

RUTTING

RUTTING

RUTTING

SHOVING

Shoving is the deflection and bulging of the road surface

generally parallel to the direction of traffic, and/or horizontal

displacement of surfacing materials. Shoving is typically caused by braking, accelerating or turning vehicles.

There are a number of factors that can make roads more

susceptible to shoving, including;

inadequate pavement strength or thickness

poor bonds between pavement layers

lack of containment of the pavement edge

SHOVING

SHOVING

SHOVING

COMPILATION

POLISHED

BLEEDING

Bleeding is the partial or complete immersion of aggregate into the bituminous binder causing low texture depth and inadequate skid resistance.

pavement surface defect in which binder is near the top of the aggregate particles. There is minimal surface texture. In severe cases the bitumen covers the aggregate.

Causes

BLEEDING occurs when the available void volume in a seal is insufficient to accommodate the volume of bitumen, aggregate fines and other detritus present.

BLEEDING

BLEEDING

REFERENCES

http://www.lgam.info

http://www.pavementinteractive.org/category/pavement-management/pavement-

distresses/flexible-pavement-distress/