What is Paver (PCI) Method? and how to apply Paver method in the distressed roads?

Thank you my dear frriend about your invitation ,,, The (PCI) mean ( Pavement Condition Index ) its a numerical index between0 and100 which is used to indicate the general condition of a pavement. It is widely used in transportation civil engineering. It is a statistical measure and requires manual survey of the pavement. PCI surveying processes and calculation methods have been standardized by ASTM for both roads and airport pavements

ASTM D6433 -11: Standard Practice for Roads and Parking Lots Pavement Condition Index Surveys

ASTM D5340 -11: Standard Test Method for Airport Pavement Condition Index Surveys

PCI was developed by the UNITED STATES ARMY GROPS OF ENGINEERING  The method is based on a visual survey of the number and types of distresses in a pavement. The result of the analysis is a numerical value between0 and100, with100 representing the best possible condition and0 representing the worst possible condition

Pavement distress types for asphalt pavements include

Low ride quality

Alligator cracking

Bleeding

Block cracking

Bumps and sags

Corrugations

Depressions

Edge cracking

Joint reflections

Lane/shoulder drop-off

Longitudinal and tranvserse cracking

Patching and utility cut patching

Polished aggregate

Potholes

Rutting

Shoving

Slippage cracking

Swelling

Weathering and raveling

I think eng.Fouad Ahmed answer the first segment of q  excellent

I will answer the second segment of q like follow:

A bituminous surface treatment (BST), also known as a seal coat or chip seal, is a thin protective wearing surface that is applied to a pavement or base course. BSTs can provide all of the following:

• A waterproof layer to protect the underlying pavement.
• Increased skid resistance.
• A filler for existing cracks or raveled surfaces.
• An anti-glare surface during wet weather and an increased reflective surface for night driving.

Historically, BSTs have been in use since the1920s, primarily on low volume gravel roads. BSTs are increasingly in use as a preventative maintenance procedure on flexible pavements of good structure.

A BST offers preventive maintenance from the effects of sun and water, both of which may deteriorate the pavement structure. BSTs create a new wearing course, as well as a waterproof covering for the existing pavement. A BST makes it more difficult for water to enter the base material, and preventing freeze thaw damage for those locations with below freezing temperatures.

BSTs also increase the surface friction of the pavement, due to the addition of the cover aggregate. This combats the effects of raveling, which can make the pavement slippery and stopping difficult. A BST gives good, gripping texture to the pavement surface.

BSTs should be applied to a distress-free to moderately distressed pavement surface. A two to four year service life is common, while five year service lives are achievable.

BSTs are created using two main materials: asphalt and a cover aggregate.

Asphalt

Asphalt (as asphalt binder, cutback asphalt or asphalt emulsion) and aggregate (uniformly graded).

The asphalt is typically an emulsion. Care must be taken with the weather on the day of construction – ideally, a warm day with low humidity is preferred. BSTs should never be constructed on rainy days or when rain is predicted. Rain can dilute the asphalt binder if it has not yet cured, bringing the binder to the top of the cover aggregate; after the water evaporates, tires can pick up the loose aggregate or track binder across the surface.

Cutback Asphalt

While cutback asphalt is historically an option for BSTs, the solvent used (usually gasoline or kerosene) is expensive and potentially dangerous. A cutback is asphalt dissolved in a solvent, allowing the asphalt to be pumped and sprayed without heating it to high temperatures. The solvent evaporates into the surrounding air, leaving the asphalt binder. Once the solvent has completely evaporated, the cutback has cured. Fast setting time cutbacks use gasoline, while kerosene is used for longer curing times.Cutback asphalt usage has declined in recent years due to pollution and health concerns.

Asphalt Emulsion

Today, asphalt emulsions are more commonly used. An emulsion consists of an oil suspended in water. In this case, the asphalt cement is the oil component. A surfactant (also called an emulsifying agent) needs to be added in order to make the oil and water mix. Having the asphalt suspended in water allows the placing temperature for a BST to be significantly lower than for a hot mix asphalt.

A surfactant offers two benefits – one, it causes asphalt to form tiny droplets that will suspend in water by lowering the surface tension between the asphalt and the water. Two, a surfactant determines the electrical charge of the emulsion. Aggregate will have an electrical charge, usually negative. Since opposite charges will attract, it is important to choose an emulsion with the opposite charge, which will enhance the binding of the asphalt to the aggregate. Cationic (having a positive charge) emulsions are typically used.

- See more at: http://www.pavementinteractive.org/article/bituminous-surface-treatments/#sthash.1fmI0Spm.dpuf

Thanks Mr.Yakoub for invitation,totally agreed with full answer given by Mr.Fouad.

Thanks for invitation,I am agreed with answer given by Mr.Fouad and Mr.Omar

The  (PCI ) ,method is based on a visual survey of the number and types of distresses in a pavement.The result of the analysis is a numerical value between0 and100.100  representing the best possible condition and0 representing the worst possible condition.

am agree with eng. fouad