Townscape precast concrete products are manufactured using aggregates to create colour. In some instances, an additional dye may be added to a product to achieve a particular type of colour depth. Slight variations are to be expected from all naturally sourced materials and whilst we work very hard to alleviate colour variations it is an inevitable part of the ageing process. In the same way, slight variation in quarry seams may occur over a period of time.
All concrete products may suffer the temporary phenomenon of efflorescence. This is in no way detrimental to the performance of the product. Its occurrence cannot be predicted, its occurrence is more probable in paving blocks than larger precast blocks.
All Townscape Precast products are manufactured using natural aggregates sourced from sustainable sources.
Surface Micro Cracking
Whilst it is impossible to remove all surface cracking from precast concrete Townscape look to mediate surface Micro cracking through careful design of all the precast concrete elements to ensure this effect is kept to a minimum. Surface Micro cracking can occur at any time during the lifetime of the concrete and is generally limited to <0.5mm. in width. Micro cracking has no detrimental effect on the underlying concrete strength.
Rock salt is a product frequently used for the elimination or prevention of ice and frost on paving. Rock salt is abrasive and continual use on precast products can cause deterioration of the surface. Alternative products in the form of granules or liquid can be used as an alternative. Granule forms known as Thaw Granules are available. Contact Dimex Limited. Tel. 0121 704 3551 Fax. 0121 704 4024.
Method for Maintaining Freeze-Thaw Affected Precast Concrete Products.
Clean away any affected loose concrete surface substrate with a stiff brush to ensure any flaking material is removed.
Patch repair the affected area if required. Townscape can provide a patch repair mix kit if needed.
Use a propriety concrete sealing system should as ‘Smith’s Polyurethane Paving Brick Sealer ‘or ‘Smith’s Permanent Concrete Sealer’ These type of sealing systems seals the surface of the concrete and are considered useful tools to help mitigate Freeze-thaw damage related issues.
Apply as directed by the sealer manufacturer.
Reapply the sealer in line with sealer manufacturers recommendations as part of your normal maintenance regimes.
Oil and Grease
Removal of oil from precast concrete.
In addition to hot water, an alkaline degreaser will greatly increase the removal rates of oil and grease. Hot water lifts the oil from the concrete, and the degreaser emulsifies the oil, allowing it to be flushed from the surface. Some contractors use at least a little degreaser for most jobs, even to remove dirt, which can be somewhat oily.
Rust will stain precast concrete. Particular care should be taken when using mild steel tools in the immediate vicinity of the concrete as the concrete can become contaminated with mild steel that will later appear as a rust stain.
Heavy rust stains can penetrate deeply into concrete, so they can be tough to remove completely. Cleaners containing oxalic acid are most effective.
Precast concrete with graffiti coating. Some of Townscape’s precast concrete products are treated with an anti-Graffiti coating. Please refer to the data sheets provided or refer to Townscape for maintenance and advice on cleaning.
Graffiti can be very difficult to remove, depending on the type of paint used. Several proprietary chemical strippers are available, many of which contain a citrus-based solvent, methylene chloride, or potassium hydroxide. Citrus-based solvents are the least aggressive and may not work on certain Paints, but they are the safest to use and often have less-stringent disposal requirements. For best results, allow products containing potassium hydroxide to soak into the concrete surface for several hours before power washing. These products also require a subsequent application of an Acid Neutralizer. Graffiti also can be removed by a special attachment that includes a tungsten-carbide nozzle that meters sand into the water stream before it exits the nozzle. But the sand will etch the concrete, which may not be desirable. In recent years, softer sodium bicarbonate abrasives have been used with power washers to remove graffiti from concrete (see Concrete Construction, February 1999, p. 87).
Precast Concrete Contaminated with chewing gum.
For small areas contaminated by the careless disposal of chewing gum several “freeze spray” products are available. For large or heavily contaminated areas professional advice should be sought. Contact Blue Diamond Tel. 01703 629944 Fax. 01703 629771 or Kincora Tel. 0161 8737713 Fax. 0161 8480552 or Graffiti Magic Tel. 0115 9422052 Fax. 0115 9244683