Sub-base Material Calculator – GSB & WMM Quantity
Use the sub-base material calculator to perform a quick preliminary calculation from project dimensions and engineering assumptions. Review inputs and verify final results against project requirements.
Introduction
Estimate granular sub-base or wet mix macadam quantities from pavement area, layer thickness and material-density assumptions.
Volume Calculation
For a uniform road layer, compacted volume is Area × Compacted Thickness. Mass is then estimated using the selected compacted or design density.
GSB and WMM
Granular Sub-Base and Wet Mix Macadam are pavement layers with different material and specification requirements. Do not interchange density or mix assumptions without checking the project specification.
Compacted vs Loose Quantity
Material delivered to site may occupy a different loose volume than the compacted layer. Procurement quantities should account for the approved compaction and conversion factors.
Worked Example
For 5,000 m² at 0.20 m compacted thickness, the geometric compacted volume is 1,000 m³. Required mass depends on the specified density.
FAQs
Q: Does thickness mean loose thickness? A: The input should be interpreted according to the calculator's field definition; construction specifications normally distinguish loose and compacted layers.
Q: Can the tool determine grading? A: No. Material grading must meet the project specification.
Disclaimer
Final road-material quantities must be based on approved pavement design, field levels, densities and specifications.