Grasscrete is reinforced cellular insitu (cast on site) concrete wherein you can grow natural grass. It is an environmental solution which is being used in UK, USA, Europe, Hongkong and other countries by Town Planners and Architects for aesthetically pleasing and environment friendly urban surroundings.
Grasscrete makes our country greener by mitigating the ill effects of modern day construction, by making them look environmentally friendly. This is achieved by growing natural grass in reinforced cellular concrete, which is designed as per the load and its usage. It can be used for various purposes and some of the prominent of these are:
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Grasscrete can be ordered as a Supply only or as Supply and Lay where we have our installers/sub-contractors who can install Grasscrete paving. In case if you want to install Grasscrete yourself or in those areas where we don't have an installer, we can supply your requirement of Grasscrete formers (moulds) and based on the laying information to be provided by us, you can use a local contractor for installation of the Grasscrete surface.
Though we recommend installation of Grasscrete paving by an experienced installer, but it is possible to lay Grasscrete by a good contractor / concreter based on the laying information to be provided by us.
Grasscrete formers (moulds) can be purchased directly either from us or our Sub-Licensees/Distributors. In those regions where we don not have a sub-licensee, Grasscrete formers can be supplied from Sydney through Courier at a nominal delivery charge.
The three seed mix specifications given in Grasscrete Brochure are ideal for inclusion in the grasscrete cavities, but for Australian conditions we suggest replacing the Browntop Bent with Bermuda Couch in mix no.1 in the warmer areas of Australia. However Bermuda grass is a creeping variety, therefore when used in regular traffic applications it can be rubbed out between the vehicle tyre and the concrete. To prevent this it may be better to seed just below the surface say 10mm. This will enable the pocket to fill up and at the same time it will be protected by the concrete running surface. Some ryegrass can also be added to the mix to try to encourage vertical growth.
Grasscrete is laid in many differing climates from extreme cold to temperate to extreme heat. For extreme heat and sun conditions some modification is required to overcome potential die-back. The use of native hot climate grass species such as Bermuda, Buffalo and Bahia grass mixes can be considered. In wide temperature ranges these can be double sown with a winter growth mix. Apart from these there are several other factors which can be considered in design to prevent burning of grass. We shall be happy to discuss and resolve these concerns, if contacted.
For traffic applications we recommend a sub-base, this will enable load to be spread for both permanent and temporary construction traffic. The depth of the sub-base should be based upon the condition of the ground relative to the required bearing capability. Grasscrete for instance is designed upon an allowable ground bearing of 45kN/sq. m. Most circumstances will see a sub-base depth of 150mm as being sufficient, this should however be proportionately increased where CBR values of 4% or less are encountered. We do not recommend the introduction of root zone mediums into the sub-base or sand-blinding layer. An organic content can vary the drainage and structural performance of the sub-base.
For non-traffic applications such as slope protection works, there is no requirement for a sub-base; on very steep slopes the placement and compaction of a sub-base could in any case be problematic. The key requirement on slopes is to prepare the sub-grade to a reasonable line and level, the finished level will tend to reflect that of the formation level. Excessive use of sand regulating layers should be avoided as this can lead to washout. For watercourses we recommend the installation of a geo-textile of appropriate flow rating below the paving layer. This prevents a loss of sub-grade should any soil pockets be washed out under water flow.
Convention tells us that if we want the best then we have to pay more for it; in some cases we often don’t even consider the better option for those very reasons. Contrary to convention the structural advantages that Grasscrete offers will help to make significant savings in both the “construction” and “whole life” costs of the project. Kerb edge restraints can be eliminated, sub-base depths can be reduced and generally the laying time is much quicker than for pre-cast. Another key feature is transportation, in a 12m container we can deliver upwards of 7200sq.m of formers (depending on type), or the equivalent of fifty truck loads of pre-cast. In fact a recent calculation proved that we were able to ship 15,000Km to a particular site and have Grasscrete installed cheaper than a pre-cast block sourced from just 20Kms away.
“Sustainable Urban Drainage” is becoming an increasingly used term with planners and developers seeking to mitigate the implications of handling surface water run-off on the local storm water network. This often involves the use of self-draining paving layers together with the installation of pre-formed sub-ground retention tanks, to store surface water for a controlled release into the drainage network. Although the use of pre-formed tanks is a fairly recent innovation, we have for 30 years published the values of having an “on-site” solution to storm water management. Whether compartmenting high volumes of water in retention tanks is the best way forward, time will tell. A more uniform percolation process will create a more natural balance; in this way there is less risk of causing shrinkage in clay soils due to urbanised modification of water tables. With the notion that Grasscrete can drain at up to 90% the rate of natural grass a safe lag time can be achieved, storing water within the system with low risk of ponding, until the ground can naturally re-charge. This lag time is beneficial in the prevention of flooding and can be extended by introducing an underlying drainage blanket across the full extent of the paved area. Rather than being a costly, engineered structure the blanket is simply another layer below the sub-base consisting of single size stone or crushed concrete wrapped within a geo-textile layer. The required permeability of the base layer of geo-textile will be dictated by the nature of the sub-grade, in granular soils the water should be allowed to pass freely through, whereas for water-logged clay soils it will be better to hold drained water so that it can be released into a piped network. Consideration should also be given to whether the drainage blanket should be used to modify waterlogged sub soils allowing ground water to rise into the drainage blanket under hydrostatic pressure, so that it can be piped away.