COPLAN - Полистироловые формовочные матрицы

PREWI Matrices are used in concreting to create fair-faced concrete surfaces.‎ Available in about 11 types of standard designs, PREWI Matrices embellish concrete easily and economically.‎ PREWI Matrices can also be used on old formwork that is no longer suitable for fair-faced concrete.‎ New formwork, on the other hand, lasts longer as it does not come into direct contact with the concrete.‎ PREWI formwork matrices are suitable for 1 casting.‎ USE PREWI polystyrene formwork matrices are supplied with the appropriate release agent already applied to the matrix: under no circumstances should additional release agent be added, neither to the polystyrene matrices nor to the wooden boards.‎ The MatriciPREWI are nailed onto the boards: this procedure is the most important for a successful casting, so it pays to pay the utmost attention and take sufficient time.‎ The PREWI Matrices should be carefully joined vertically and horizontally, exerting sufficient pressure between them so that there is no grout leakage.‎ Then proceed by nailing the MatricePREWI on the upper and lower horizontal parts (i.‎e.‎ the parts most stressed during casting) with nails of approx.‎ 40-50 mm, one every 15 cm.‎ On the vertical part, however, one nail every 50 cm is sufficient.‎ The nails should normally be applied slightly askew on the upper part of the PREWI matrix (corresponding to the lower part on the casting), except for the Andante and Andantino types, where it is recommended to apply them on the lower part of the matrix.‎ To prevent the nail heads from being "drowned" in the casting with a consequent risk of rusting, it is advisable to nail them so that the heads are a couple of mm deeper than the surface of the polystyrene.‎ The MatriciPREWI can be trimmed to size with a sharp knife, holding it at an angle and making the cut on the side in contact with the casting.‎ The tie rods mustalways rest on the wooden formwork and never on the matrix: special 21-, 29- and 51-mm-diameter dies are available for drilling the holes on the matrix.‎ Before casting, any holes and joints should be filled in to prevent grout leakage.‎ Plastic or fibre cement spacers should be placed 1 piece approx.‎ per m2 .‎ It is advisable to distance the reinforcement from PREWIMatrix by at least 2 cm to avoid the risk of rust stains on the exposed side.‎ It should be borne in mind that the size of the MatriciPREWI inside the formwork varies from 1 to 7 cm, so the thickness of the wall to be built must be adjusted accordingly.‎ The Matrici PREWI are also suitable for circular formwork (columns, arches, etc.‎), both concave and convex.‎ To bend and adapt the matrices on curved parts, it is sufficient to notch the back slightly.‎ The same principle applies to making corners: a cut of a few mm is made on the back at the corner, then proceed by carefully bending the die.‎ Care should be taken with the additives contained in the concrete.‎ Some additives may damage the matrix, so it is recommended to apply a certain amount of the additive in the mix to a sample of the matrix or to carry out preliminary casting tests.‎ If, 48 hours after casting, the matrix surface is damaged and/or the exposed side is stained, it is a sign of incompatibility between the type of additive used and PREWI Matrix.‎ Therefore, proceed by changing the type of additive or eliminating the additive by adding more water (approx.‎ 5%) to the mix.‎ Thawing can take place, as usual, after approx.‎ 2 - 3 days.‎ If the stripping time is longer, it should be taken into account that the concrete surface will become darker.‎ In the case of multi-storey constructions (e.‎g.‎ a multi-storey building), it is advisable to maintain the same stripping cycles in order to avoid colour differences in the concrete.‎ Any polystyrene residue on the exposed side can be easily removed with the help of iron brushes and/or high-pressure water.‎ PRELIMINARY TESTSFor the selection of the desired finish and to carry out all practical tests regarding temperature, mix composition, admixture compatibility, stripping procedures, production rates, etc.‎, free samples of cm .‎Free samples measuring 20 x 30 cm are available for each type of PREWI Matrix in the catalogue.‎ STORAGEPREWI Matrices should be stored away from sun and rain.‎