Terms we use
The engineering and trade words on this site, in plain English, from A to Z. If a word you need is missing, ask us: sales@gridmats.com.
- Annual rate contract
- A 12-month agreement that prices every call-off in the year at the annual rate, whatever its size, against a commitment of 10,000 m² or ₹1 crore a year. See Annual rate contract.
- Base
- The compacted layer of crushed stone under the surface. It spreads the load of the wheels to the ground. The GridMats grid sits on the base.
- Call-off
- One purchase order placed under a rate contract, for one site, at the contract rate.
- CBR (California Bearing Ratio)
- A test of how strong the ground is. A higher CBR means firmer ground, which needs a thinner base.
- Cell confinement
- The grid's cells hold the infill in place, so it cannot spread sideways under wheels. This is what lets loose stone or gravel behave like a firm surface.
- Cement-treated gravel (S1)
- Stone chips mixed with a little cement, filled into the grid and compacted. It sets into a hard surface with no saw-cut joints.
- Compaction
- Pressing a layer with a roller or plate compactor so that it becomes dense and strong.
- Cube test
- Small cubes of a cement mix are made on site and crushed in a laboratory after 7 or 28 days to check their strength. An S1 surface opens to trucks once its 7-day cubes reach 2 MPa.
- DLP (defect liability period)
- 1 year after handover, in which GridMats deals with manufacturing defects in the products it supplied. It applies only when your team shares project status updates at each hold point, as our Terms and Conditions set out.
- Ex-works, ex-GST, ex-freight
- A price at our factory, before GST is added and before transport.
- FOB (free on board)
- An export price that includes delivery onto the ship at the named Indian port.
- GreenPro
- The Confederation of Indian Industry's (CII) certification for green products.
- Gross vehicle weight
- The total weight of a loaded vehicle. We describe trucks this way, for example "up to 49 t gross"; the pavement itself is designed from the axle loads.
- GSB (granular sub-base)
- A layer of graded crushed stone or gravel laid on the prepared ground, below the base.
- Hold point
- A stage of the work where the next step waits until the last one has been checked and released.
- Infill
- What fills the grid's cells: stone chips, gravel, soil and grass, or concrete.
- Installed cost
- The cost of the finished surface per sq ft or m²: the grid, the base, the infill and the labour. It depends on the site, so it is designed for each site.
- IRC (Indian Roads Congress)
- The body that publishes India's road design codes.
- kg CO₂e
- Kilograms of carbon dioxide equivalent: all the greenhouse gases a product causes, counted as if they were carbon dioxide.
- Lab load test (t/m²)
- A panel is pressed in a laboratory until it fails, and the load is given in tonnes per square metre. It compares panels; the capacity of a finished road comes from its design for the traffic and the ground.
- LCA (life-cycle assessment)
- A count of the greenhouse gases a product causes over its life, in kg CO₂e per m².
- m² and sq ft
- Square metres and square feet: 1 m² = 10.764 sq ft. We show prices per sq ft first, with the price per m² in brackets.
- M25 concrete
- Concrete with a strength of 25 MPa at 28 days.
- MLP board
- A plywood-substitute board pressed from multilayer plastic waste such as tetra packs, chip packets and aluminium-lined film, with no adhesive. See MLP boards.
- Modulus improvement factor
- How much stiffer a layer of stone becomes with the grid than without it, measured in a laboratory.
- MPa (megapascal)
- A unit of strength or pressure. 1 MPa is about 10 kg on each square centimetre.
- Permeable
- Lets rainwater soak through the surface into the ground instead of running off.
- PO (purchase order)
- The buyer's order. With GridMats, on-site training is built into the product rate, so there is one PO.
- SOP (standard operating procedure)
- Our step-by-step installation method, which we train your contractor's team to follow.
- Subgrade
- The natural ground under all the layers of a road or yard.
- VDF (vehicle damage factor)
- A number that turns the real mix of vehicles into standard axle loads, so a pavement can be designed for its traffic.
- WMM (wet mix macadam)
- A base layer of graded crushed stone mixed with water, laid and compacted.