M-CRETE 400 – Cement based Tanking System

• Mechanically remove all damaged concrete or failed repairs back to a sound core.
• Wherever possible, the full circumference of the steel reinforcement should be exposed to at least 25mm behind the bars and 50mm beyond the point at which corrosion is visible.
• On cutting back, feather edges must be avoided.
• The perimeter of the repair area should be stepped to a depth of 10mm by means of saw, disc cutting or preferably using a power chisel.
• The areas to be repaired must be free from all unsound material, dust, oil, grease, corrosion by-products and organic growth.
• Smooth surfaces should be roughened, all loose material and surface laitance removed and reinforcement cleaned to bright steel using wet grit blasting techniques or equivalent approved methods.
• If chlorides are absent from the concrete and environmental constraints preclude the use of blasting then hand held power tools such as a needle gun, angle grinder or power wire brush can be used to remove all loose.
  corrosion by-products back to bright metal.
• The strength of the concrete sub-base should be a minimum of 20 MPa.
• The prepared substrate should be thoroughly soaked with clean water until uniformly saturated without any standing water.
• In winter, use warm water or a heat source to ensure the substrate temperature is ≥ 5ºC before application.

• All exposed steel reinforcement should be treated with 2 coats of M-PRIME 200 – Aluminium Based Metal Primer applied by brush (See separate Data Sheet for full details).
• NB: When carrying out repairs in new constructions, it is not necessary to fully expose any reinforcing bars.

• M-CRETE 400 is highly polymer modified and as a result concrete surfaces do not generally require a primer.

Prior to mixing please ensure the following:

• Ensure the substrate temperature is between  -10/ +40°C.

• M-CRETE 400 should be mechanically mixed using a forced action pan mixer or in a clean drum using a drill and paddle.
• A normal concrete mixer is NOT suitable.
• For normal applications, typically use 3.5 litres of clean water per 25kg bag.
• For part bags, use 5.5 volumes of powder to one volume of water.
• In cold temperatures, tepid water may be used to adjust working life.
• For screeding applications or larger pockets in decks up to a maximum depth of 100mm; a clean, washed, Medium Grade concreting sand can be introduced, up to 50% by weight.
• For deep repairs up to a maximum of 300mm in a single application, or where a pourable concrete is required, coarse, clean aggregates (5-10mm size) can be introduced into the mix, in up to equal proportions by weight, without adversely affecting its physical performance.

Please Note: It is vital to the success of the application that these instructions are strictly adhered to. Maxkote Ltd cannot be held responsible for any product failures due to incorrect mixing.

• For normal applications, M-CRETE 400 should be compacted, using a placing technique to remove entrapped air, in layers not exceeding 50mm in vertical situations, or 100mm deep in pockets.
• When bulking out to the maximum of 300mm, support with shuttering and compact to remove entrapped air.
• For repairs which require multi-layer applications, it is important to ensure that the previous layers are well keyed and stable but not fully set (usually 15-30 minutes dependent upon temperature) prior to the application of subsequent layers.
• Final profiling of a high quality is achieved with a steel float.
• When applying material to floors, the area should be divided up and each bay
  completed within the working life of M-CRETE 400.
• Typically, bay sizes should be restricted to 1m2 but please consult our Technical Department for further advice.
• Do not polish the surface with a steel float, but use a stiff brush on the wet surface to provide a slip-resistant finish.
• Note: M-CRETE 400 must be allowed to cure for a minimum of 30 minutes prior to total immersion.

• Normal concreting procedures should be strictly adhered to.
• It is important that the surface of the mortar is protected from strong sunlight and drying winds with polythene sheeting, damp hessian or similar.

• 13.3 litres per 25kg bag. Up to 23 litres when bulked out with aggregate.
• A 25kg bag as supplied covers 1.33m² at 10mm thickness.

• M-CRETE 400 APG PDF