Highway Construction Flexible Pavement

Presentation Contents• Unpaved Roads• Paved Roads • Shoulders• Horizontal Alignment, • Surface Regularity of Pavement• Asphalt• Porous Asphalt• Stone Mastic Asphalt• Gap Graded Asphalt

A level of horizontal surface which is made from native materials of the land surface.

Unpaved Road---

1. Definition

Unpaved Road

Gravel Roads

Earth Tracks

Earth Roads

Unpaved Road---1.1 Types of Unpaved Road

Are the simplest (Low Volume Roads) and generally consist of parallel rust, separated by vegetation delineating a rural access rout.

These Tracks are not Engineered Impassable during or after wet weather condition. Carries less than five vehicles per day.

1.1.1 Earth Tracks---Definition

Are classified as those which no-imported gravel is used. The in-situ material is cleared of vegetation and lightly compacted. Periodic maintenance should be applied.

1.1.2 Earth Roads---Definition

Have a designed layer of imported materials. Typically constructed to a specific standard. Provide all weather surfaces. Vertical and horizontal alignment is based on a specific standard. Regular maintenance is carried out.

1.1.3 Gravel Roads---Definition

The Durable surface material, laid down on an area intended to sustain vehacular or traffic.

Paved Road---

1. Definition

Paved Road in Romania

Paved Road---

1.1. Type of Paved Roads

1.1.1. Unbound Roads---

Course and Fine Aggregate, Crushed hard rock, Free from sand and dust

Well graded

Sand, gravel & crushed aggregate Free from organic matter

Well graded

1. Crushed Aggregate (Crushed Rock & gravel, Hard, Clean Durable) 2. Wet mixed Road-base (Crushed Rock & gravel, Hard, Clean Durable)

Aggregate Fine & Course, Mineral Filler, Bituminous material

Aggregate Fine & Course, Mineral Filler, Bituminous material

Prime-Coat

Drainage

Sub-Base

Road-Base

Surfacing

Binder

Tack-Coat

Wearing

Cut-back Bitumen of the grade MC-70

Rapid-setting, Cationic bitumen, Grade RS-1K

1.1.2. Bound Roads---

Course and Fine Aggregate, Crushed hard rock, Free from sand and dust

Well graded

Sand, gravel & crushed aggregate Free from organic matter

Well graded

1. Bituminous Road Base (Aggregate Fine & Course, Mineral Filler, Bituminous material )

2. Cement Treated Base (Water, Cement & Aggregate)

Aggregate Fine & Course, Mineral Filler, Bituminous material

Aggregate Fine & Course, Mineral Filler, Bituminous material

Prime-Coat

Drainage

Sub-Base

Road-Base

Surfacing

Binder

Tack-Coat

Wearing

Cut-back Bitumen of the grade MC-70

Rapid-setting, Cationic bitumen, Grade RS-1K

Bound Unbound

High Traffic Flow Low Traffic Flow

Costly Economical

Bound and Unbound Road---2. Usage And Comparison

Shoulders---Definition

Is a the portion of the road way contiguous with the traveled way for accommodation of stopped vehicles, for emergency use and for lateral support of base and surface courses.

Road Shoulder

Plus Highway, Malaysia

Road Shoulder---Types:

1.1 Paved Shoulder 1.2. Earth Shoulders 1.3 Gravel Shoulder

Surface Regularity ---Description• Important quality of a screened or floor surface which is often

describes as a measure of waviness of the road surface.• International Roughness Index (IRI) is used.• Shall be measured before opening to the traffic

Straight segment of road ways (Tangent) Connected to suitable curves (horizontal curves).

Measured from middle of the road.

Horizontal Alignment---Description

Surface Course (Asphalt)---Description• Any of various dark colored solid bituminous substances native in

various areas of the earth and composed mainly half hydro carbon mixtures

Surface Course

Porous Asphalt

Stone Mastic Asphalt

Gap Graded Asphalt

Hot in-Place Recycling

Cold In-Place Recycling

Polymer Modified Asphaltic Concrete

Surface Course (Asphalt)---Types

Porous asphalt is a special-purpose wearing course. It is produced using open-graded aggregate mixed with polymer-modified binders and contains a relatively high and interconnected air voids after compaction

Porous Asphalt---Description

Coarse & fine Aggregate Mineral Filler Bituminous Binder Tack Coat

Porous Asphalt---Materials

---Benefits Improved skid resistance at high speeds, especially during wet

weather. Reduced hydroplaning effects. Reduced splash and spray. Reduced headlight reflection and glare on wet pavement surface. Reduced rolling tyre noise levels.

Stone mastic asphalt or SMA is a polymer modified hot bituminous mixture with a large proportion of coarse aggregate and rich bitumen-filler mastic.

Stone Mastic Asphalt---Description

Coarse & fine Aggregate Mineral Filler Bituminous Binder Stabilizing Agent

Stone Mastic Asphalt---Materials

---Benefits Provide Durable surfacing High resistance to rutting Good skid resistance

Gap Graded Polymer Asphalt is used by many developed countries. It is a wearing course containing polymer modified bitumen and made up of 100 percent crushed aggregates.

Gap-Graded Asphalt---Description

Coarse & fine Aggregate Mineral Filler Bituminous Binder

Gap-Graded Asphalt---Materials

---Benefits Durable Strength and safety of driving surface in dry or wet weather The mix is suitable to solve cracking and deformation

problem High Skid resistance

Porous Asphalt Stone Mastic Asphalt Gap-Graded Asphalt

Parking Loats High Stress AreasClimbing Lanes/ where excessive axial loads are expected

High Stress AreasClimbing Lanes/where a high volume of heavy vehicles are considered

Drive Ways

Side Walks

Bike Paths

Playgrounds

Tennis Courts

If Proper Maintenance Min 20years life

Comparison Of Surface Course---Application and Usage Comparison