simple road estimate with easy example

To prepare road estimate we have to calculate the quantity of material required in different layers used road construction.

Here we will calculate quantity of material required in each layer and will skip other factors like site clearing, embankment, etc.,

Given,

length of road = 1000mm = 1m

varies slope = 1:2 (H:V)

Width –

carriage way = 3500mm = 3.5m

paved shoulder = 1500mm = 1.5m

earthen shoulder = 1000mm = 1m

Depth –

bituminous concrete = 25mm = 0.025m

dense bituminous macadam = 50mm = 0.05m

sub grade = (500,150,100)mm = (0.5,0.15,0.1)m

granular sub base = 150mm = 0.15m

wet mix macadam = 125mm = 0.125m

road estimate calculation

road estimate (2d section)

we will calculate material only at left hand side of road section and will multiply by 2 to get total quantity.

Sub grade

layer – 1

Length = 1m

depth = 0.3m

width = Width of (carriage way+paved shoulder+earthern shoulder)+(depth of(2 layers sub grade+granular sub base+wet mix macadam+dense bituminous concrete+bituminous concrete)*2)

= 3.5+1.5+1+((0.3+0.15+0.125+0.125+0.05+0.025)*2) = 7.55m

Quantity = lxbxd = 1*7.55*0.3 = 2.265m^3

layer – 2

Length = 1m

depth = 0.15m

width = Width of (carriage way+paved shoulder+earthern shoulder)+(depth of(2 layers sub grade+granular sub base+wet mix macadam+dense bituminous concrete+bituminous concrete)*2)

= 3.5+1.5+1+((0.1+0.15+0.125+0.125+0.05+0.025)*2) = 7.15m

Quantity = 1*7.15*0.15 = 1.073m^3

layer – 3

Length = 1m

depth = 0.1m

width = Width of (carriage way+paved shoulder+earthern shoulder)+(depth of(1 layers sub grade+granular sub base+wet mix macadam+dense bituminous concrete+bituminous concrete)*2)

= 3.5+1.5+1+((0.15+0.125+0.125+0.05+0.025)*2) = 6.95m

Quantity = 1*6.95*0.1 = 0.695m^3

Total Quantity = 2.265+1.073+0.695 = 4.033m^3

Granular sub base

Length = 1m

depth = 0.15m

width = Width of (carriage way+paved shoulder+earthern shoulder)+(depth of(wet mix macadam+dense bituminous concrete+bituminous concrete)*2)

= 3.5+1.5+1+((0.125+0.125+0.05+0.025)*2) = 6.65m

Quantity = 1*6.65*0.15 = 0.998m^3

Wet mix macadam

length = 1m

depth = 0.125m

WMM -1 (bottom)

width = Width of (carriage way+paved shoulder)+(2*depth of granular sub base)

= 3.5+1.5+(2*0.15) = 5.3m

Quantity = 1*5.3*0.125 = 0.663m^3

WMM -2 (bottom)

width = Width of (carriage way+paved shoulder)+depth of granular sub base

=3.5+1.5+0.15 = 5.15m

Quantity = 1*5.15*0.125 = 0.644m^3

Total Quantity = 0.663+0.644 = 1.307m^3

Prime coat

length = 1m

width = width of WMM = 5.15m

Quantity = 1*5.15 = 5.15m^2

Track coat above DBM

length = 1m

width = width of prime coat = 5.15m

Quantity = 1*5.15 = 5.15m^2

Dense bituminous macadam (DBM)

length = 1m

depth = 0.05m

width = Width of (carriage way+paved shoulder)

= 3.5+1.5 = 5m

Quantity = 1*5*0.05 = 0.25m^3

Track coat below DBM

length = 1m

width = Width of (carriage way+paved shoulder)

= 3.5+1.5 = 5m

Quantity = 1*5 = 5m^2

Bituminous concrete

length = 1m

depth = 0.025m

width = Width of (carriage way+paved shoulder)

= 3.5+1.5 = 5m

Quantity = 1*5*0.025 = 0.125m^3

Seal coat

length = 1m

width = Width of (carriage way+paved shoulder)

= 3.5+1.5 = 5m

Quantity = 1*5 = 5m^2

Sl. No.DescriptionNo. of elementsQuantityTotal QuantityUnit
1Sub grade24.0338.066m^3
2Granular sub base20.9981.996m^3
3Wet mix macadam 21.3072.614m^3
4Prime coat25.1510.3m^2
5Track coat above DBM25.1510.3m^2
6Dense bituminous macadam (DBM)20.250.5m^3
7Track coat below DBM2510m^2
8Bituminous concrete20.1250.25m^3
9Seal coat2510m^2

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