Dry Shake Sprinkles
Dry Shake Sprinkles are a blend of aggregates and cements bagged into 25kg bags or supplied in bulk 1 Tonne bags which are mainly used for application by a dry shake spreader machine.
The dry powder material is applied to freshly laid concrete and relies on the free water in the parent concrete to hydrate the cements in the powder blend. The hydrated material then bonds monolithically with the sub concrete to form a hard wearing, abrasion resistant and sometimes coloured surface to the slab.
Dry Shakes have been used for many years and have a proven track record. It is important though to use an experienced installer.
Some of the advantages of using a dry shake sprinkle include: –
- To provide a fibre suppressant in steel fibre reinforced concrete floor slabs.
- Steel fibre slabs have steel fibres reinforcing the concrete three dimensionally. Inevitably fibres are then present in the top and on the top of the concrete slab. These fibres need to be covered over to provide a consistent finish to the slab.
- To provide an enhanced abrasion resistance making the wearing surface of the slab less likely to wear quickly under normal working conditions.
- Dry shake material composition and careful selection of aggregate types. Aggregates can vary from natural sands, quartzites, metallic and titanium aggregates being used.
- Each aggregate type will impart different properties into the finished surface.
- To provide a corporate or decorative colour to the concrete surface finish.
- Dry Shake Sprinkles come in a variety of colours and clients can choose a colour they desire.
- Light Reflectance can be increased with careful selection of the dry shake colour, aggregate and cement.
Wet on Wet Toppings
Wet on Wet or as it is sometimes known as Fresh on Fresh has been around for a number of years. Due to the advent of Laser Screed and large bay construction techniques that are employed by concrete specialists over the past 20-30 years, wet on wet went out of fashion.
Traditionally wet on wet was laid in small area ‘long strip’ panels that allow greater control of the application of the topping onto the freshly laid concrete. Faster construction builds dictated that floor slabs are installed much quicker by using large pour construction techniques usually using mechanical equipment like Laser Screed. This made it much more difficult to construct a wet on wet system.
Fairly recent improvements and construction techniques now allow wet on wet toppings to be constructed on large pour floor slabs once again, if carried out by experienced teams.
Wet on Wet put simply is concrete being poured into a floor slab being prepared and then receiving a ‘batch’ of specialist aggregates and cements that have been mixed in a static pump mixer for the correct period to the correct consistence. The ‘wet screed’ is then treated to lay it to level and screeded to the required flatness to cover the entire area of hardening concrete to encompass the full slab range. Timing of the laying process is critical as the ‘screed/topping’ has to bond monolithically to the parent concrete.
Once the ‘screed/topping’ has been laid it has to be left until it is ready to start the finishing techniques. Finishing is slightly different to normal power floating of concrete. Timing and the type of equipment is varied to actually finish the wet on wet screed/topping successfully. Hand floating is required at edges and around obstructions i.e. columns, pits, pipes etc. Power floating is normally carried out on main open areas.
When power floating and power trowelling is complete and the topping has hardened it should be immediately cured normally using a water based curing membrane.
The Wet on Wet material can achieve a compressive strength of up to 80N/mm² depending on the aggregates, cements and mix proportions. This results in a very hard dense surface finish.
Advantages of Wet on Wet
- Very high compressive strength topping finish
- Very high abrasion resistance
- Scratch resistant
- Dust resistant
- Impact resistant
- Can be used in a variety of colours
- Material choice can be specially selected to the clients requirements within his working environment.
Where Should Wet on Wet be Used?
- Light, medium and heavy-duty warehouses and industrial units.
- VNA and wide aisle warehouses in logistical buildings.
- Power stations
- Military installations
- Pharmaceutical units etc.
Types of Work
A mechanised system of laying concrete floor slabs where a machine trims, levels and vibrates concrete up to 350mm deep with the correct specification concrete. Tolerances up to FM1.
High Tolerance Floor Slabs
Precision levelled slabs are often required for many types of installation. For Free Movement tolerances where very tight tolerances are required over the whole slab. This may well be for specialist equipment e.g. air cushion transport etc. are being used, we can lay slabs to FM1 (Free Movement). For racking areas the tolerance changes to Defined Movement and Malin can lay large areas of slab to DM1 (Defined Movement). With both specification Laser Screed construction methodology can be utilised.
Upper Floors and Mezzanines
These can be slabs on metal decking and pre-cast planks. These are normally laid using hand screed methodology. Alternatively, the smaller Laser screed systems, copperhead, S840 type machines can be used if access and egress can be provided. Tolerances depend upon stiffness of the supporting structure which includes structural steelwork and decking/planks.
Hand Screeded Flooring
Generally used for smaller areas of offices, small sheds etc. where the mechanised system cannot be used. Tolerances are generally FM3 or FM4
Specialist slabs situated inside an insulated panel box building. Sizes can vary from just a small unit inside a retail outlet to a whole building. The slabs are normally hand laid although the smaller Laser Screeds, Copperhead and S840 can be used if access and egress can be provided. Tolerances are dependant upon methodology used. If required very high tolerances, DM1 or similar can be achieved using the ‘long strip method’. More generally FM3 or FM4 tolerances are adopted using the hand lay systems.
Generally specified for outside slabs and roadways for traffic into and out of warehouses etc. The most common finish is a brush finish to provide a textured running surface for the vehicles using the hardstandings and roadways. Various techniques can be adopted using both mechanical Laser screed type systems and hand lay systems. These slabs are normally laid to falls into a designed surface water drainage system.
Ground Bearing Slabs
These slabs rely entirely on full support from the sub strata. The reinforcement detailing, and design is specific for controlling the drying shrinkage of the concrete.
Suspended Pile Supported Slabs
These slabs have reinforcement designed to distribute loadings into the concrete capable of spanning between a designed pile system. Reinforcement includes designed rebar, special designed mesh sheets and steel fibres etc.
Hydraulically Efficient Slabs to Falls
Mainly used in wet areas where the manufacturing processes include a washout water being drained away. Bottling plants, fish and meat processing plants all commonly use this system.
Multi Story Car Parks
Commonly laid to falls and having a brush type finish to provide grip for vehicles. Some carparks have other finishes applied to the finished concrete.
Waste Treatment Plants
Various configurations exist for waste treatment plants. Generally slabs are laid to falls but some areas are laid ‘flat’. Concrete has to be designed specifically for the type of waste being treated which can be very aggressive to concrete.
Various configurations exist for recycling centres. Generally slabs are laid to falls but some areas are laid ‘flat’. Concrete must be designed specifically for the type of waste being treated which can be very aggressive to concrete and extremes of temperature, up to 70º Celsius can exist between areas of concrete a small distance away. In other centres very aggressive machinery e.g. heavy face loading shovels, can be used and the concrete has to have a very ‘tough’ abrasion resistance. Joints need to be carefully considered.
Main Site Plant Resources
- 2 No S-22E Laser Screeds, these are the latest machines out of the world renowned Somero stable. Both machines have been upgraded to incorporate the latest roller plow head technology…….
- 2 No SXP-D Laser Screeds
- 2 No SXP Laser Screeds
- 2 No S-240 Laser Screeds
- 1 No S840 Laser Screed
- 1 No Copperhead X3
- 1 No Power Rake 2
- 1 No Miniscreed
- Numerous power float options to cater for all types and configurations of concrete floors.