The operating principle of the expansion anchor bolt system is a threaded stud, stamped sleeve, shell or wedge bolt, which is assembled from a tapered nut, nail, screw, stud or bolt, depending on the type of expansion anchors used.
The compressive force of the expansion bolts system is drilled against the wall to transfer the load to the substrate. The expansion anchor is mainly made of steel, stainless steel, plastic,nylon, zinc alloy and other materials. Expansion anchor bolt is a special fasteners designed for foundation materials in different installation sites. Expansion anchor bolts are fixed and anchored to the base of concrete, masonry, brick, block, stone, or solid wall by fastening bolts or nuts are considered torque control, while expansion anchors driven by nails or plugs are considered deformation control. Compared with the torque control anchor, the deformation control anchors can produce higher initial compression force. Compression expansion anchors can also be pre expanded and / or combined with nails. The expansion mechanism on this type of anchorage is achieved by compression during drilling and then applying force to produce a holding force.
The expansion bolt design principle mechanism allows for excellent consistent retention values in concrete. Once inserted into the drilled hole, the nut turns clockwise. This action will pull the anchor body upward, so that the expansion clamp moves upward along the conical working end of the conical anchor, and expand the product stress between the expansion component and the base material, thus generating the expansion force and realizing the anchoring and fixing function of the installation object.
According to different installation base materials and different installation purposes, expansion anchor bolts are mainly made of carbon steel, nylon, zinc alloy, stainless steel and other materials, and accessories of different materials are pre assembled to form the expansion anchor products.
Steel expansion anchors systems are threaded stud, stamped sleeve tube, shells, or wedge bolt assembled which is achieved by a tapered cone nut, nail, screw, threaded stud or bolt depending on the used styles of expansion anchors. The compression power of the expansion system against the wall drilled hole the anchor to transfer the load to the basis material. They are expanded to fix the objects in the concrete, masonry, brick, stone or the solid wall substrate by fastening a bolt or nut are considered to be torque controlled while those that are actuated by driving a nail or plug are considered to be deformation controlled.
Stainless steel expansion anchors are an ideal corrosion-resistant material that will withstand long-term exposure to the environment, especially saline. It has the innate ability to form a protective surface that prevents corrosion. However, it is susceptible to corrosion from chloride solutions, i.e. saline environments with high amounts of sodium chloride. If this is the case, then stainless steel 316 might be acceptable or could consider to plate by hot dipped galvanized or by dacromet coating on the surface.
Nylon fixing anchor is pre assembled in concrete, solid masonry and hollow wall structure by fixing and nails. The expansion nail design of nylon fixed anchor can be removed as required. There is a small slot in the head of the nail to accommodate a small screwdriver blade. When turned counter clockwise with the screwdriver, the nail will be rolled back into part of the nylon plug. This allows the hammer to hook the protruding head of the nail and pull it out of the nylon plug. After pulling out the expansion nail completely, the nylon fixing anchor body can be pulled out.
Zinc alloy expansion anchor is a kind of expansion anchor, which is composed of tubular shield and conical nut, and is pre assembled with a strong spring band. The convex shape on the tapered nut prevents the anchor body from rotating or moving in the hole during expansion. It is made of high quality zamac material, which has better anti rust and anti-corrosion properties than ordinary zinc electroplating. It is widely used for expansion joint and fixation of light and medium masonry, concrete, block and brick concrete places. The expansion effect at both ends is specially designed to distribute the tensile strength load on the whole length of the bolt. This type of design and use where bolts are suitable for side pressure or vibration.
Huge anchor bolts, in highway projects, are used to bear steel beams, trusses, girders and hefty road signs. These anchor bolts are used to anchor these elements and support them against strong winds. Endurance limit of the bolts is considerably lesser than manufactured strength.
Bulky anchor bolts are also used to keep down power transmission towers and in radio tower reaction blocks.
The nuclear energy industry utilizes steel anchor bolts in several ways. It used to hold the reactors and fix them to the bases.
Large anchor bolts known as “tie-downs”, are used to hold down huge water storage tanks. They are used to handle wind loads.
Anchor bolts that are used in mining are known as rock anchors. A part of the anchor is attached to rock or concrete by cement grout, resin, or fixed by a mechanical anchor. The upper part of its length is left un-attached, but is fixed later to provide resistance against corrosion. Anchor bolts are used in retaining walls, tunnels, mines, stabilizing slopes, and provide protection from rock fall.
Some types of anchor bolts can be pre-installed and hence are easy to use. All one has to do is fix it into the hole and the one by one affix the remaining pieces.
There are several types of anchor bolts and are used extensively in different projects. As they are available in different sizes as well as heavy and light duty they have a wide range of uses. There is an anchor bolt for every type of requirement.Easy to Use
Stainless steel expansion anchor is an ideal corrosion-resistant material, which can withstand long-term exposure to the environment, especially saline water. Stainless steel used in anchors has the inherent ability to form a protective surface to prevent corrosion.
In the actual installation and use of expansion anchor products, it is generally necessary to drill a pilot hole for placement and fixation. The outer diameter and depth of drilling hole are different according to different base materials and different product specifications. The product installation instructions should be strictly adopted to ensure sufficient expansion force to realize scientific installation purpose. At the same time, with the development of science and technology and various new materials are constantly invented and applied in the process of industrial production, the expansion anchor industry is also in continuous progress and development.