Flexcrete Monomix HD
Class R4 High Strength Structural Repair Mortar
Please contact your local branch for price and availability.
High strength, waterproof, fibre reinforced, shrinkage compensated mortar for the structural repair and reinstatement of concrete.
CE-marked in accordance with BS EN 1504-3 Class R4.
Structural repair, rendering and profiling of vertical, horizontal and overhead surfaces, including trafficked areas. Suitable for repair methods 3.1, 3.3, 7.1, 7.2 as defined by BS EN 1504 -3.
Incorporates the latest proven cement chemistry, micro-silica, fibre and styrene acrylic copolymer technology.
Pre-packaged material only requiring mixing with water on-site.
Can be applied up to 80mm in a single layer in vertical, horizontal and overhead situations.
High bond strength exceeds tensile strength of concrete, ensuring monolithic performance of the repair.
Dense matrix offers low permeability to water at 10 bar pressure and very high diffusion resistance to acid gases and chloride ions.
Resistant to sulphates to class DS-5M of BRE Special Digest 1.
Improved tensile and impact strength. Excellent low sag properties.
Economic mortar requiring no substrate or inter-layer priming. Part bags can be mixed.
Easily over-coated with specialist membranes to provide further protection and aesthetic properties.
Flexcrete Monomix HD is a single component, polymer modified, fibre reinforced, standard density, high strength cementitious repair mortar. The thixotropic nature of the product enables easy high build hand and trowel application for the structural repair of voids and the rendering and re-profiling of vertical, horizontal and overhead surfaces. Can be applied using spray techniques in large areas. It is supplied as a single component system requiring only the addition of clean water.
13.1litres per 25 kg pack
Mechanically remove all damaged concrete, brick or stone 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. 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.
TREATMENT OF STEEL REINFORCEMENT;
All exposed steel reinforcement should be treated with 2 x 1mm coats of STEEL REINFORCEMENT PROTECTOR 841 applied by brush (See separate Data Sheet for full details). NB: When carrying out repairs in new construction, it is not necessary to fully expose any reinforcing bars.
PRIMING OF CONCRETE;
Monomix HD is highly polymer modified and as a result concrete surfaces do not generally require a primer. Highly porous substrates should be primed with BONDING BRIDGE 842 prior to the application of the repair mortars (See separate Data Sheet for full details).
Monomix HD 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 between 2.3 – 2.7 litres of clean water per 25kg bag. For part bags, use 7 – 8 volumes of powder to one volume of water. Typically, for high build applications use 2.5 litres of clean water per 25kg bag which gives a water: powder ratio of 10%. Normal mixing time depends upon the type of mixer used; 2-3 minutes is average. Mix so as to entrain as little air as possible. Use without delay. Please Note: It is vital to the success of the application that these instructions are strictly adhered to. Flexcrete cannot be held responsible for any product failures due to incorrect mixing.
Monomix HD can be applied by float or trowel as a render, resulting in application thicknesses of 80mm, even in soffit situations. If necessary, support with shuttering to allow for compaction if working to reveals, etc. The application thickness achievable is dependent upon the substrate and care should be taken to ensure that an initial thickness of Monomix HD is well placed and adhered before building up to larger depths. For repairs which require multi-layer applications, it is important to ensure that previous layers are well keyed and stable but not fully set (2-6 hours dependent on temperature) prior to the application of subsequent layers. No inter-layer priming is required. Final profiling of a high quality is easily achieved with a steel float. For larger areas of repair, Monomix HD can be applied using spray techniques. At the mixing stage, use the higher level of water addition to produce a mix suitable for this method of application.
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 FLEXCRETE CURING MEMBRANE WB, polythene sheeting, damp hessian or similar (See separate Data Sheet for full details).
CLEANING AND STORAGE;
All tools should be cleaned with water immediately after use. Materials can be stored for 12 months in dry, frost free conditions with unopened bags at 20°C.