What is the difference between Granular Sub Base (GSB) & Wet Mix Macadam (WMM) in Pavement structures? What is the maximum size of the aggregates to be used in GSB & WMM?
This question actually needs very long & detailed answer,It can not be answered in 2 lines.However,Let me summarize this as possible. The flexible pavement contains 4 main pavement layers that are as following Sub-grade(Natural soil) , Sub-base , base & Surface Course. The surface course coRead more
This question actually needs very long & detailed answer,It can not be answered in 2 lines.However,Let me summarize this as possible.
- The flexible pavement contains 4 main pavement layers that are as following Sub-grade(Natural soil) , Sub-base , base & Surface Course.
- The surface course contains 4 layers as well that are as following Prime Coat , Binder Course , Tack Coat & Wearing Surface.
- The Binder Course & Wearing Course contains the Following (Coarse aggregate + Fine aggregate + mineral filler + Asphalt)
- Size & Gradation of aggregate(Coarse & fine) shall be as following as per AASHTO …> Coarse aggregate (Retained on Sieves#4 , 8 & 10) …> and the fine aggregate (Passing from Sieves#4 , 8 & 10) …> Mineral filler (at least 70% pass from sieve#200)
- Regarding the Subgrade soil shall be Fine or Coarse aggregate and the soil shall have group index less than 4 to be suitable for use as per AASHTO
- Group index equation as following (G.I=0.2*a + 0.005*a*c + 0.01*b*d)
Komal Bhandakkar
Difference between granular sub-base and wet mix macadam in payment structure: The wet mix macadam mostly consists of laying spreading and compacting of clean, crushed, well-graded granular material that is prepared and approved granular sub-base. Single compacted wet mix macadam player shall not beRead more
Difference between granular sub-base and wet mix macadam in payment structure:
The wet mix macadam mostly consists of laying spreading and compacting of clean, crushed, well-graded granular material that is prepared and approved granular sub-base.
Single compacted wet mix macadam player shall not be less than 75mm.
Whenever we are using vibrating compacting equipment then compacted depth of a single layer of the course of the subway may be up to 200 mm.
Wet mix macadam shall be prepared in an approved of water macadam mixing plant.
Here replacing the aggregate fraction should be retained on 22.4 mm sieve with materials of passing from 22.4 and written on 4.75 mm.
While the addition of water, the evaporation loss shall be considered the mixed material shall be uniformly wet and segregation will take place.
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