WMM(Wet Mix Macadam) quantity / Compaction Factor value for WMM / Loose thickness of WMM Layer

Wet Mix Macadam (WMM) quantity / Compaction Factor value for WMM / Loose thickness of WMM Layer 

In this article we shall discuss three important points about wet Mix Macadam (WMM)

1- How can we calculate the required WMM  quantity? 

2 -  What is value of compaction factor for WMM?

3- How much loose thickness should be taken to get proper compacted layer thickness ? 

1- How can we calculate the required WMM quantity?



Let us consider

Length of WMM Bed(L) = 1 Km = 1000 Met.
Breadth of WMM Bed(B)= 7 Met.
Thickness of WMM Layer (T)  = 150 mm =0.150 Met.

Max. Dry Density (MDD) =2.230 Gram/ Cubic Centimeter = 2230KG/ Cubic metre

Note -  The value of MDD is calculated by conducting proctor density test as per IS 2720 (part -28) : 1983 (Reaffirmed - May 2015).

Then
Volume of WMM Layer = ( Length of WMM Bed X Width of WMM Bed X Thickness of WMM Layer)

Volume of WMM Layer = L X B X T
 Volume of WMM Layer   = 1000 X 7 X 0.150  Volume of WMM Layer    = 1050 Cubic Metre

We Know That
Mass = Volume X Density
in this case -

Mass = Volume X MDD

Putting the value in the Formula

Mass = 1050 X 2230 KG
Mass  = 23,41,500 KG

To convert above quantity in Tonn
We Know That

1 Tonn = 1000 KG
Then

Mass =(2341500/ 1000) Tonn
Mass   = 2,341.5 Tonn


Hence required WMM quantity is 2,341.5 Tonn. 


To know about WMM technical specifications kindly visit on below link 🔗 

wet-mix-macadam(wmm) technical specifications

2 -  What is value of compaction factor for WMM?

Density of Blended aggregate /Density of WMM Mix = 1.60 gram/cc  to 2.0 gram/cc
                  = 1600 - 2000 KG/ cubic metre

In this case
Let us consider

Density of Blended aggregate /Density of WMM Mix = 1.80 gram/cc = 1800 Kg / cubic metre

Value of Max. Dry Density (MDD) = 2.230 gram/cc = 2230 KG/ cubic metre

Compaction Factor = (Max.Dry Density/Density of Blended Aggregate )

        =2.230/ 1.80
        =1.2388 = 1.24
Hence compaction factor = 1.24

3- How much loose thickness should be taken to get proper compacted layer thickness ? 

Compaction factor = 1.24
Thickness of WMM Layer  = 150 mm

Hence
 Loose thickness of WMM Layer = ( Compacted layer thickness X Compaction Factor )
 = 150 X 1.24
 = 185.83 = 186 mm ( Take)

Hence Loose Thickness of WMM Layer is 186 mm. 

Thanks a lot 
Mukesh Kumar
 www.gyanofcivilengineering.com