What We Need To Know About Spray on Concrete Driveways
The science and technology of spray on concrete driveways gets better every year. Let’s see how it achieved this status and also the new ways of using concrete resurfacing in general. In the mid-1950’s and 60’s another option for applying concrete resurfacing was invented. Known as the wet method, this operation required the use of ready-mixed concrete. Similar to the dry method, air is pressurized and used to push the concrete mix into a hose and out of a spray nozzle designed specifically for concrete installation.
When utilizing the wet method, the hose operator will not need to correct the mix of water and dry concrete materials because that operation has already been done by pre-mixing the concrete before delivering it to the compressed air machines. Contractors who like this technique enjoy the fact there is no possibility of mixing too much water into the mixture, which may lead to a weak concrete texture and lack of hardness. While those who prefer the dry method believe that the correctly mixed concrete and water create a better product which is stronger and more durable than the ready-mix used with the wet method to install a spray concrete driveway.
Spray On Concrete Driveway Using the Dry Pack Method
Another way is by using a dry pack for installing a spray on concrete driveway requires premixing for specific automated concrete mixing stations that have aggregate metering accuracy which follows the government mandated regulations for such projects. The method allows contractors to ready dry pack on site as well if the size of the job is limited or small and if the delivery of concrete mixture to the job site inside hermetically sealed packaging cannot be done fast enough to prevent premature curing. Mixed dry pack has only 2 hours from the time of mixing to the time of application before setting permanently.
The installation of a spray on concrete driveway using dry pack is projected layer-by-layer, with a coating – 5-6 cm thick. This can be permitted to raise the thickness of layers if any quick-hardening substances are used on condition that freshly laid material will not slide off and its effective gravity during the installation exceeds 2.2 g/sm3 when measured.
For spray concrete driveway placement, particularly made transport is utilized, whereby using the dry method of the mix of cement, sand and any gravel used in the same amounts is pumped out with compressed air by means of the flexible hose into the nozzle, this is where the mix is moistened with the water. If the wet methods are utilized, premixed concrete is fed continuously to the hopper for use by the sprayer to install the spray on concrete quickly and efficiently.
Additionally, there are other products and equipment that concreters can use, spray on concrete driveway installers should have complete knowledge of the other products utilized in the industry to aid choose the most effective equipment for pumps, fibers, plasticizers, concrete retarding agents and much more. Whichever product the customer selects, concreters should know how to work with the substances to finish the spray concrete driveway as quickly and successfully as possible.
Apart from spray concrete driveways, other applications for spray on concrete include; highway and railroad tunnels mining operations slope stabilization building foundations hydropower, projects canal lining, bridge rehabilitation, concrete repair & restoration, seawalls, mass transit, parking garages, and residential projects.
The Qualities of a Spray on Concrete Driveway
When a spray concrete driveway is installed correctly it averages 5,500psi of finished strength. The outcome of spray on concrete driveway is not as common as the usual cast-in-place concrete when it comes to the application surface, reinforcement, and of course method of application. Most of the time the wet process is the process selected for high-strength installations like driveways.
Compared with conventionally installed concrete driveways, the qualities of spray concrete driveways can be adjusted and improved by mixing in some additives or admixtures like the silica fume, air-entraining admixtures, fibers and accelerators for concrete setting. These accelerators are frequently added at the pre-mix concrete facility in order for the spray on concrete driveway to cure and harden on time after the actual installation.