What is water bound macadam roads?

What is water bound macadam roads?

WBM road means water bound macadam road. The wearing surface of WBM road consist of clean and crushed aggregates which are mechanically interlocked by rolling operation. The material is bound with filler material (which are also called as screenings) and water, laid on prepared base course.

Why is it called water bound macadam?

The water is used to bound crushed aggregates with the filling material by rolling. Thatswhy it is called as Water Bound Macadam(W.B.M).

What is difference between water bound macadam and wet mix macadam?

Here are the differences between WMM (Wet Mix Macadam) and WBM (Water Bound Macadam) roads….Difference Between WMM and WBM Road.

WMM Road	WBM Road
In WMM roads stone aggregates and binders are used.	In WBM roads stone aggregates, screenings, and binder material (Stone dust with water) is used.

What uses and limitations of WBM road?

Disadvantages of W.B.M road(low-cost road)

• W.B.M provides inferior riding surface as compared to bituminous/cement concrete road.
• W.B.M road surface do not provide sanitary surface since they can not be washed and cleaned easily.
• This road surface cause dust nuisance under pneumatic tyred traffic.

What is water bound?

Definition of water-bound 1 : restrained from going by flooding waters. 2 : consolidated or held together by water especially : thoroughly soaked at the time of laying so that a natural cement formed from water and stone dust unites the particles —used of a macadam road surface.

What means macadam?

macadam • \muh-KAD-um\ • noun. : a roadway or pavement of small closely packed broken stone. Examples: The sloping, curved street saw light traffic and had a smooth macadam surface that made it popular with skateboarders. “

What is density of WBM?

Effect on Maximum Dry Density (MDD): it is observed that WBM-A exhibited MDD of 20.60kN/m3 and WBM-B exhibited MDD of 22.66kN/m3, indicating 10% increase in MDD for WBM –B after partial replacement by steel slag, specific gravity of steel slag is higher compared to conventional aggregates.

How many types of water bound are there?

Physically bound water is categorised as two types namely, bound water (intracellular water) and strongly bound water (cell wall water) (Caurie, 2011) .

What is macadam in road construction?

Macadam is a type of road construction, pioneered by Scottish engineer John Loudon McAdam around 1820, in which crushed stone is placed in shallow, convex layers and compacted thoroughly.

What is the difference between macadam and asphalt?

Asphalt is defined as: “a mixture of substances with gravel, crushed rock, or the like, used for paving.” To deepen the history, the word macadam is derived from the “inventor” of the modern paving surface, John Loudon McAdam.

What is difference between DLC and PQC?

PQC stands for Pavement Quality Concrete made with larger size aggregates following IRC specifications and laid over a Dry Lean Concrete(DLC), concrete subbase course. PQC construction is explicitly used for highway concrete pavements and runway pavements to take heavy loads.

What is the size of WBM?

Quantity of materials

Type	Size range, mm	Sieve size, mm
Coarse aggregate	63 to 45 mm	0.91 to 1.07
Stone screening type-B	11.2 mm	0.20 to 0.22 for base coarse 0.16 to 0.18 for surface course

What is material used in WBM?

The coarse aggregates used in W.B.M generally consists of hard varieties of crushed aggregates or broken stones. However, soft aggregates like over burnt bricks metal, kankar and laterite may be used.

What is the minimum width of WBM road?

In general, for minor or ordinary roads, the thickness of a single compacted layer should be 75 mm and is sufficient.

What is the meaning of bound water?

Definition of bound water : water that is an essential component of various materials (such as animal and plant cells or soils) from which it cannot be removed without changing their structure or composition and distinguishable from free water in such ways as by its inability to dissolve sugar or to form ice crystals.

How is water bound?

Water molecules have a strong electrical polarity, meaning that there is a very strong positive charge on one side of the molecule and a strong negative charge on the other. This causes the water molecules to bond to each other and to other charged surfaces, such as soil minerals.

What are the different types of macadam road?

TYPES OF MACADAM ROAD

• Water bound macadam.
• Traffic bound macadam.
• Bituminous macadam.
• Cement macadam.