Surface Course of Flexible Pavement

Wednesday, October 2, 2013 12:08

Surface Course of Flexible Pavement

This is the top layer which comes in contact with traffic. It normally contains the highest quality materials. 

typical detail of road section

It serves to prevent the entrance of excessive quantities of surface water into the underlying base & sub-grade.

Surface Course is Sub-divided into two Layers

Wearing Course

A layer in direct contact with traffic loads.  It is meant to take the impact of traffic and can be removed and replaced as it becomes worn.

Intermediate/Binder Course

This layer provides the bulk of the Hot Mix Asphalt structure.  It’s main purpose is to distribute load. It may compose of one or several HMA sublayers.

Definition of Hot Mix Asphalt

Wednesday, October 2, 2013 12:08
Posted in category Pavement and Foundation

Hot Mix Asphalt HMA

Hot mix asphalt (HMA) is “the black stuff” used as a pavement material. Its a combination of aggregate and asphalt binder mixed together at elevated temperatures that forms a hard, strong construction material when cooled to suitable temperatures. Continue Reading »

Base Course of Flexible Pavement

Monday, September 30, 2013 19:41

Base Course of Flexible pavement

The first coat to be placed, on top of your proper sub-base, is the base course. It provides additional load distribution and contributes to drainage and frost resistance.  Continue Reading »

Sub-Base Course of Flexible Pavement

Monday, September 30, 2013 19:26

Sub-Base Course of Flexible Pavement

flexible pavement structure Continue Reading »

Flexible pavements

Monday, September 30, 2013 12:36

Flexible Pavements

Flexible pavements are those which are surfaced with bituminous (or asphalt) materials.

Its “flexible” since the total pavement structure “bends” or “deflects” due to traffic loads. Generally this type of pavement requires some sort of maintenance or rehabilitation every 10 to 15 years. Continue Reading »

Types of traffic controlling devices | Traffic Signs

Wednesday, June 19, 2013 16:46

Traffic Signs

Traffic signs are means of warning, regulating and informing the drivers.

Material for traffic signs

Material should be such that Continue Reading »

Traffic controlling devices | What are pavement markings

Tuesday, June 18, 2013 14:37

Traffic controlling devices

The devices which are used to control and regulate the flow of traffic are called traffic controlling devices.

These are of three types:

  1. Pavement markings.
  2. Traffic signs.
  3. Traffic signals.

Pavement markings

Pavement markings are in the form of bands or strips of paints, which are Continue Reading »

What is Lane occupancy ?

Sunday, June 9, 2013 20:36

Lane occupancy

Lane occupancy is the ratio of the sum of the lengths of the vehicles to the length of the road section in which those vehicles are present. Continue Reading »

Definition of traffic density | Headway and Spacing | Clearance and Gap

Saturday, May 25, 2013 18:02

Traffic density

Traffic density is the number of vehicles occupying a given length of the highway in a traffic lane. 

It is expressed as vehicle/mile or vehicle/kilometer. Continue Reading »

Definition of speed | Traffic volume and Traffic rate of flow

Sunday, May 19, 2013 15:29

Speed

Distance covered by vehicle in unit time is known as speed.

Its units are miles/hour or km/hr. Continue Reading »