Citygrid is designed for heavy duty applications and fully compliant to SuDS (sustainable urban drainage systems). Extensively tested and proven, citygrid will:
– Minimize surface water run off
– Reduce flood risk
– Improve water quality
– Encourage biodiversity
Material: 100% recycled polyolefins
Nominal size: (L x W x H) 60 x 40 x 8 cm / 24″ x 15.75″ x 3.15″
Unit weight: 9 kg / 19.8 lb (37,5 kg / 82.67 lb per 1 m² panel)
Coverage: 4.17 grids/m² or 0.39 grids/ft2 (1 grid = 0.24 m² / 2.58 ft²)
Connection type: Tongue and groove
Infiltration rate: 2,500 mm/hr for gravel
» High compressive strength
» Flexible and resistant to cracking
» Anti-slip & UV resistant
» Harmless to the environment
» Meet SLW60 loading category (vehicle up to 60 metric tonnes / 66 tons gross weight)
» Within HSE manual handling guidelines
Heavy duty permeable ground grid infiltration
1. Grass seeded or gravel finish
2. Citygrid units (permeable grid)
Grass: Good quality, free-draining friable topsoil, seeded at 6 -10 lbs per 1,000 ft² or 35–50 g/m², pre-seeding fertilizer applied.
Gravel: Clean, free-draining angular crushed rock 0.2 – 0.6″ or 5–15 mm. Do not use rounded or river washed gravel.
3. Grit bedding
Clean coarse 0.08 – 0.25″ or 2–6 mm grit compacted to 0.8″or 20 mm.
4. Geotextile filtration layer
Non-woven needle-punched, minimum 3.25 oz/yd² or 100 g/m2.
5. Free-draining engineered sub-base
Free-draining granular base with a depth to suit the anticipated loading. N.B. Standard granular base is not suitable as it’s not free-draining.
6. Geotextile separation layer/Geogrid
30/30 geogrid on a non-woven needle-punched geotextile, minimum 3.25 oz/yd² or 100 g/m².
7. Sub soil
Establish CBR value to calculate depth of free-draining granular base.
» Tried & Tested
Porous paving is increasingly used in North America and worldwide for access, parking lots, truck parking and bus terminals. The first porous paving systems were made of concrete, but concrete has weight, flexibility and durability limitations. This is why grids made of 100% recycled plastic are so effective.
As well as environmental benefits and the ability to take very high dynamic loads, Heavy Duty Permeable Ground Grid flexes under pressure rather than breaking like equivalent concrete products. Heavy Duty Permeable Ground Grid is not plagued by frost damage (unlike concrete), is lightweight by comparison and very robust when handled. Heavy Duty Permeable Ground Grid doesn’t crack if dropped, it can be carried/installed by a single person and complies with manual handling guidelines.
» Strength testing
The most common testing for heavy duty loads is SLW60. Although useful, these tests only prove if a grid can bear the static load of a multi-axle 66 ton truck. Most plastic grid systems meet this standard.
As well as meeting SLW60/HS-25 requirements, unlike most competitors, citygrid (Heavy Duty Permeable Ground Grid) has been extensively tested to DIN EN ISO Standards for:
» Bending stress at 41°/73°/149°F (5°/23°/65°C)
» Timed bending stress at 1, 24 and 100 hours
» Tensile strength (ultimate and timed)
» Compressive strength at 1, 2, 10 and 20% deflection
» Charpy impact resistance
» Shore hardness (impact)
» Ball striking hardness
» Density, water absorption, thermal expansion and screw pull-out strength
Standard concrete units have a flexural strength of at least 725 psi or 5,000 kN/m². Heavy Duty Permeable Ground Grid achieves 2,200 psi or 15,200 kN/m² so it can flex under pressure instead of cracking. Typical trucks exert a static tire load of around 120 psi or 833 kN/m². The Heavy Duty Permeable Ground Grid crushing strength of 2,600 psi or 18,000 kN/m² means it bears virtually any load.