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Sika® Rugasol® MH Extra

CONCRETE SURFACE RETARDER FOR CONSTRUCTION JOINTS

Sika® Rugasol® MH Extra has been specifically designed and formulated for obtaining a clean exposed aggregate finish at the face of construction joints where concrete with strengths in excess of 20 MPa are used. (For concrete strengths less than 20 MPa, use Sika® Rugasol MH.) Sika® Rugasol® MH Extra is applied directly to steel or timber formwork prior to the placement of concrete to achieve a clean and uniform depth of aggregate exposure.  Sika® Rugasol® MH Extra retards the setting process of cement on the surface of concrete in contact with the treated formwork to a depth of approx. 3 ‐ 5 mm.  

  • Using Sika® Rugasol® MH Extra to obtain a mechanical key at construction joints eliminates the costly expense of bush hammering, scabbling or sandblasting
  • Aggregate exposed using Sika® Rugasol® MH Extra remains unbroken and firmly embedded in the concrete, ensuring that a strong bond is achieved at the construction joint between existing and new concrete.
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Product Data Sheet Show all documents

Usage

  • Sika® Rugasol® MH Extra is used to achieve an excellent ‘keyed’ surface on vertical construction joints where positive bonding is required between existing and newly poured concrete
  • It can also be used to achieve decorative architectural finishes on concrete with strengths above 20 MPa.

Advantages

  • Using Sika® Rugasol® MH Extra to obtain a mechanical key at construction joints eliminates the costly expense of bush hammering, scabbling or sandblasting
  • Aggregate exposed using Sika® Rugasol® MH Extra remains unbroken and firmly embedded in the concrete, ensuring that a strong bond is achieved at the construction joint between existing and new concrete.

Packaging

10 litre non returnable containers

Colour

Dark pink emulsion

Product Details

Product Information

Chemical Base

Solvent based emulsion

Shelf Life

Twelve (12) months when stored as stated.

Storage Conditions

Store in unopened original containers between +5°C and +25°C. Do not expose to direct sunlight in storage.

Application

Application Information

Ambient Air Temperature

Application Temperature: +10°C ‐ +30°C

 
Consumption

Consumption

Coverage Rate: 4 – 6 m²/litre
Application steps

APPLICATION

Formwork should be clean and free from any release agent or other contaminant that may inhibit adhesion. It is recommended that Sika® Rugasol® MH Extra be applied with either a brush or roller. A thorough and uniform rate of coverage is required to achieve a uniform and even depth of etch. Sika® Rugasol® MH Extra should be protected from direct sunlight once application is complete. Once the Sika® Rugasol® MH Extra has dried (1½ ‐ 2 hours approx.) concrete can be carefully poured against the treated forms or moulds.

Removal

  • For best results, forms or moulds should be removed as soon as possible after the concrete is poured
  • Some of the soft cement paste will adhere to the forms when the mould is stripped. This can be removed easily from both the formwork and concrete while still soft by washing and brushing
  • Always clean the concrete immediately after stripping or removal from the mould as the soft cement paste soon hardens.  Note: Sika® Rugasol® MH Extra will retard the set of cement paste by up to 5 mm in depth. This depth depends on the thickness of the coating, the time elapsed before the formwork is removed, the cement content of the concrete and the ambient air temperature
  • Formwork to be reused may be scraped off and recoated with Sika® Rugasol® MH Extra as soon as required
  • If the retarding action is no longer needed any residual material should be completely removed

Cleaning

Brushes and rollers can be cleaned using Sika® Thinner C or a low grade solvent.

 

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