Construction of flexible pavement

The Public Works Department establish in the year 1854. At that time PWD was responsible for

the construction of roads,buildings,railways as well as flood control,irrigation and military

works.The organization’s construction works is directly connected to the national programme of

development and reconstruction.

• PAVEMENT-

Pavement is load bearing and load

distributery component of a road.

• PURPOSE OF PAVEMENT-

1. Load support.

2. Smoothness.

3. Drainage.

4. All weather operation.

5. Direction and guidance.

• TYPES OF PAVEMENT STRUCTURE –

Flexible Pavement. (Hot mix asphalt (HMA) pavements)

2. Rigid Pavement. (Portland cement concrete (PCC) pavements)

Construction of Subgrade

Materials- Selected Soil , Moorum , Gravel , Aggregate

maximum 50 mm.

Construction Method –

•The subgrade is constructed by spreading the loose soil and compacting the same at optimum moisture content of the soil in layer.

•The maximum compacted thickness of each layer is generally limited to 200 mm as per MORTH.

WET MIX MACADAMPLANT

Construction of Bituminous Pavement layers

Three types of bituminous layers-

1. Bituminous Macadam.2. Penetration Macadam.3. Bult up spray Grout.

It consist of crushed aggregate and bituminous binder heated and mixed in a hot mix plant at specified temperature , transported to the construction site, laid with a mechanical pawer and compacted by roller.

Material used : Bitumen binder of grade VG -30,20 and Max size of aggregate 50mm.

Bituminous Penetration Macadam Base Course

The coarse aggregate of specified size are first spread and compacted well in dry state. Compected thickness 50-75 mm. After compacting of dry aggregates, hot bituminous binder of specified grade is spread in large quantity on the top of this layer. Filling up a part of void and binding by key aggregate.

It consist of a two layer composite construction of compacted crushed stone aggregate with bituminous binder applied after each layer and key aggregate placed on the top surface of the second layer.

Submitted By Mr. Deepak Bhatt

Submitted to :Mr. Jaibeer ChandU.I.T Dehradun