Single-Component, Structural Grade, Polymer Modified, Concrete Reinstatement Mortar.

dura.®rep HS is a one-component polymer modified cementitious blend of Portland cement, fine aggregates and chemicals requiring only the addition of clean water to produce a high-strength concrete reinstatement mortar. When fully cured, dura.®rep HS exhibits excellent compatibility with concrete in terms of movement. Due to the mortar’s low water requirement it cures quickly to a dense durable fi nish with its surface being impervious and water repelling.

Uses
  • Dams, weirs, flumes, bridges, concrete reservoirs and building structures.
  • Potable water retaining structures.
  • Silos and water cooling towers.
  • Reinstatement of large or small patch repairs.
  • Specifically designed for repairs where good abrasion resistance and high compressive strengths are required.
  • Elements requiring high chloride and carbon dioxide resistance.
  • Harbour wharf repairs.
Advantages
  • Alkaline properties provide protection to the reinforcing steel.
  • High levels of early strengths.
  • High abrasion resistance.
  • Applied by the wet or dry spray process for fast, exceptionally high-build repairs with enhanced characteristics.
  • Extremely low permeability provides maximum protection against carbon dioxide and chlorides ingress.
  • Excellent bond to the concrete substrate.
  • Compensates for shrinkage in the plastic and hardened phase.
  • Constant quality and performance (pre-blended).
  • Non-toxic.
  • Contains no chloride.
Typical Physical Properties

Compressive strengths – MPa ASTM C109

  • 24 hours 20
  • 28 days 50

Flexural strengths – MPa

28 days 9

Equivalent thickness of concrete – CO2 barrier

  • 10 mm thick >200 mm
  • Coefficient of thermal expansion 9 to 12 x 10-6/°C

Setting time @ 20°C

  • Initial set 2 hours
  • Final set 4 hours
  • Average density 2 300kg/m3
Surface Preparation

The substrate must be sound, fi rm and clean, free of oil, grease, loose particles and cement laitance, old layers of paint, or other contaminants. All edges to be repaired must be square cut to a minimum of 10 mm deep, perpendicular to the surface, followed by the removal of all unsound material. When using compressed air for cleaning, the air must be clean and oil free.

Never feather edge the product. Where breaking out is not required, roughen the surface and remove any laitance by light scabbling or grit-blasting.

All metal to be coated must be clean, mechanically sound and dry. Expose all corroded reinforcing steel and grit blast. A clean bright fi nish is required ensuring that all corrosion products are removed particularly behind the steel. The anchor pattern should be approximately 40 to 60 microns from peak to valley. Prime before fl ash rusting occurs, see data sheet dura.®rep ZR primer.

Bonding / Priming

The substrate should be thoroughly soaked with clean water and any excess removed prior to applying one coat of dura.®bond GP primer and scrubbing it well into the surface. dura.®rep HS can be applied as soon as the primer becomes tacky. If the dura.®bond GP is too wet, vertical build up of the dura.®rep HS mortar may be difficult. In exceptional circumstances, e.g. where a substrate/repair barrier is required or where the substrate is wet or likely to remain permanently damp, epidermix 345 bonding aid should be used. Contact the a.b.e.® technical department for further information.

Mixing

A suitable size mixing vessel that will accommodate full bag lots using a pan mixer or a heavy duty mechanical drill type mixer and spiral paddle stirrer that operates around 400 – 500 r/min is recommended. Tumble type mixers are not recommended. For normal applications, place 2,5 to 3 liters of drinking quality water into the mixer and, with the machine in operation, add one full 25kg bag of dura.®rep HS and mix for 3 to 5 minutes until fully homogeneous. The powder must always be added to the water. Dependent on the ambient temperature and the desired consistency, the amount of water required may vary slightly but should not exceed 3 liters per 25kg bag of dura.®rep HS.

Coverage

25kg of dura.®rep HS powder mixed with 2,7 liters of water yields approximately 12 liters.

Application

Apply the mixed dura.®rep HS to the prepared substrate by gloved hand or trowel. Thoroughly compact the mortar onto the primed substrate and around the exposed reinforcement.

dura.®rep HS can be applied up to 10 mm thickness in vertical sections but up to 100 mm thickness in smaller pockets or with the use of formwork. If formwork is used, it should have properly sealed faces to ensure that no water is absorbed from the repair material. In horizontal locations, dura.®rep HS can be applied up to 100 mm thickness.

If sagging occurs during application to vertical surfaces, dura.®rep HS should be completely removed and reapplied at a reduced thickness onto the correctly reprimed substrate.

Note: the minimum applied thickness of dura.®rep HS is 5 mm.

dura.®rep HS can be applied by the wet or dry spray process. In circumstances where large areas of repair are required, the rapid placement and higher build attainable by these methods offer economic advantages over hand-trowelling. This type of repair generally provides better density to the product in place with enhanced bonding characteristics.

The yields offered are theoretical and will vary based on water demand changes for different application methods. dura.®rep HS is finished by striking off with a straight edge and closing with a steel float. Wooden, plastic fl oats, or damp sponges may also be used to obtain different surface textures. Do not overwork the surface.

Cleaning

Clean tools with water before the mortar hardens. Hardened material can only be removed by mechanical means.

Protection on Completion

Like all cement based materials dura.®rep HS must be cured immediately, as soon as the surface will not be marred. This is carried out by applying, by brush or spray, a suitable curing compound like dura.®bond GP or as recommended by a.b.e.®’s technical department. Large areas should be cured as trowelling progresses (0,5 m2 at a time) without waiting for completion of the entire area. In rapid drying conditions caused by high winds or direct sunlight additional precautions should be included like sealing with polythene sheeting having the edges taped down. This may include damp hessian behind the sheeting to prevent moisture loss. Similarly in cold conditions, the repaired area must be protected from freezing. For additional protection properties, dura.®rep HS is fully compatible with the dura.®cote range of protective coatings.

Temperature and Relative Humidity

Surface and ambient temperatures must be at least +5ºC and rising, ideally between 20ºC and 30ºC.

Model Specification

High-strength cementitious mortar for horizontal and vertical concrete repairs.

The repair mortar will be dura.®rep HS, a single-component, high-strength, polymer-modifi ed cementitious mortar applied in accordance with the recommendations of a.b.e.® Construction Chemicals, including dura.®rep ZR steel primer and dura.®bond GP acrylic bonding agent or epidermix 345 where necessary. The mortar will have a minimum 28-day compressive strength of 50 MPa.

Packaging

dura.®rep HS is supplied in 25kg polyethylene lined paper bags.

Handling & Storage

This product has a shelf life of 12 months if kept in a dry cool place in the original packaging. In more extreme conditions this period might be shortened.

Health & Safety

dura.®rep HS is alkaline and must not be allowed contact with skin and eyes. Avoid inhalation of dust during mixing by wearing dust masks. The use of gloves, eye protection and dust masks is advised. Immediately wash with water in the event of contact with skin. Splashes into eyes should also be washed immediately with plenty of clean water and medical advice sought thereafter.

Important Note

This data sheet is issued as a guide to the use of the product(s) concerned. Whilst a.b.e.® Construction Chemicals endeavors to ensure that any advice, recommendation, specification or information is accurate and correct, the company cannot – because a.b.e.® has no direct or continuous control over where and how a.b.e.® products are applied – accept any liability either directly or indirectly arising from the use of a.b.e.® products, whether or not in accordance with any advice, specification, recommendation, or information given by the company.

Further Information

Where other products are to be used in conjunction with this material, the relevant technical data sheets should be consulted to determine total requirements. a.b.e.® Construction Chemicals has a wealth of technical and practical experience built up over years in the company’s pursuit of excellence in building and construction technology.