Fasteners are one of the most important elements of any facade system. Informed choice dowels augurs high quality and durability of facade system. Fasteners plugs into the base bearing bearing base buildings are divided into three types: full-bodied strong foundation (concrete, clay and calcium silicate brick); durable hollow base (alkaline bricks, hollow concrete blocks or keramzitbetonnye), full-bodied porous base (concrete, gas silicate blocks). In modern dowel technique can be implemented by various principles of anchoring. For each type of carrier base is selected optimum principle of anchoring. Thus, in the strong anchoring of the bases used by frictional forces, and porous - a form of anchoring sleeve anchors. Why is it necessary? Porous base (concrete, gas silicate) have an increased ability to fracture at constant pressure. This is the reason for the buildings that have a porous base, it is inappropriate to use anchors, anchoring which is carried by friction. Keep in mind that the anchoring force of friction in aerated concrete in the initial period (up to 3 thousand hours) there are reasonable values ??the efforts of the test plugs "on digging", then the situation is much worse, and after 10 thousand hours is interpreted to dowel the maximum load is much reduced. This fact is confirmed by numerous studies. Anchoring form liner plugs to avoid pressure on the material or, more precisely, to make it not work when determining the dowels. Projections on the sleeve plugs formed in aerated concrete "pockets" that do not work on raspor, and the shift of the material. This is a fundamental difference between it possible to achieve maximum reliability, and most importantly, long-lasting anchorage in such a difficult material for the dowels, as aerated concrete. When fastening anchors in drywall is not there is a particular complication because drywall dense material and plug it sits just fine. Although, as such, need to tighten the plug in the drywall there. Screw into the plasterboard perfectly "sit" and without dowels. Head shape dowels This aspect is often, sometimes at the highest and technically competent level, overlooked. To properly assess the significance of head shape in the dowels, you must clearly understand how to "work" dowel: how he perceives and transmits the load bearing base. When considering the interaction between the head dowels and brackets in the front system with air gap should focus on the influence of head shape on that interaction. For reliable transfer the load from the bracket in the supporting base through spacer element is very important to fit the head to the bracket was happening on the plane. Unfortunately, in practice very often occurs through so-called frame anchor dowels for mounting brackets. Frame dowels are tapered head "flush" and used for fixing window frames and wooden beams, they reinforce the elements that have cone-shaped mounting socket or a small compressive strength, allowing it to form a slot in the installation process. If you secure the dowels by web steel or aluminum bracket with a hole under the anchor plug, head contact with the dowel bracket is in the best case for the line, and at worst (in the case of patent foramen ovale) - two points. In this case not to speak of reliable and durable mount, because the polymeric material sleeve anchors, which separates the head element and the spacer bracket, will be simply cut with sharp-edged hole time bracket. This will lead to backlash and risk the destruction of the connection. In addition, there is the likelihood of moisture penetration and corrosion of the spacer element. Most manufacturers of electrochemical corrosion of anchor dowels, the Board has in a way that the bracket and spacer element shared sleeve anchors. This recommendation is very important, since its implementation eliminates the likelihood of galvanic corrosion that occurs in the presence of a pair of metal (nails, screws), facing away from each other in the electrochemical series, and a conductive medium (water). For example, zinc and aluminum, steel and aluminum, corrosion-resistant steel and aluminum to form pairs that are prone to electrochemical corrosion. Electrochemical corrosion of the danger of significant reduction in the strength properties of the material, resulting in possible destruction of the compound. Avoid galvanic corrosion is possible, if the sleeve anchors a polymer washer that separates the material of the spacer element and the bracket system. In addition, the polymer puck more even distribution of load when tightening the spacer element and prevents mechanical damage to the bracket, such as bursting. P.S. To hammer a nail in the wall plug is not recommended, as dowel loses all its properties, and these do not reach the durability design.
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