Anchor bolts are usually used to connect non-structural and structural elements to concretes. The connections are made by an assembling of different components such as: steel plates, anchor bolts, and stiffeners. Anchor bolts are designed for transferring different types of loads like tension forces and shear forces. The connection between structural elements are represented by steel column attached to the reinforced concrete foundation. Usually, non-structural elements are attached to a structural one which is represented by the connections between facade systems and the reinforced concrete walls.
The strongest and simplest form of an anchor bolt is cast-in-place. Its embedded end consisting a standard hexagonal washer and head bolt, 90 bend, forged or welded flange. They are used in concrete – steel composite structures as shear connectors. Other fields of use include anchoring machines to poured concrete floors and buildings to concrete foundations. Many typical disposable aids are produced to secure and align these anchors to concrete. Their position must be coordinated with the reinforcement layout. Various types of CIP anchors might be distinguished.
For all types of cast in place anchors, the load transfer mechanisms is a mechanical interlock, the embedded part of anchors in concretes transfer and the apply load with bearing pressure at the contact zone. At failure condition, the level of the bearing pressure can be higher than 10 times of the concrete compressive strength, if pure tension force is transferred, Cast-in-place anchors are also utilized in masonry applications, placed in wet mortar joints during cast blocks and laying of brick.
Force transfer mechanisms are based on friction of the mechanical interlock, guaranteed by expansion forces.
Force transferring mechanisms are based on the mechanical interlocks. Drilling operation allows to create a contact surface between the anchor head and the hole’s wall where bearing stresses are exchanged.
Force transferring mechanisms are based on the bond stresses provided by binding materials. Both threaded rods and ribbed bars can be used and change of the local bond mechanisms can be appreciated experimentally. On ribbed bars, the resistances are prevalently due to shear behavior of the concrete between two ribs whereas threaded rods friction prevails. Bonded anchors are referred as chemical anchors or adhesive anchors. Anchoring materials are adhesives, usually consisting of vinyl, polyester or epoxy resins. This anchor’s performance types of load bearing capacity under tension loads, is related to cleaning conditions of holes. Experimental results shows that the reduction of the capacity is up to 60%. The very same applications also for moisture condition of concrete. For wet concrete the reduction is using 20% polyester resin. Other issues are represented by high temperatures behaviors and creep responses.
The force transferring mechanisms of the screw anchors are based on the concentrated pressures exchange between the screws and the concretes through the pitches.
Tapcon screws are popular anchors which stand for self-threading concrete screws. Larger diameter screws are called as LDT’s. This type of fastener requires pre-drilled holes using a Tapcon drill bit and then screwed into holes using a standard hex or Philips bit. These screws are often white, blue, or stainless. They are also seen in marine or high stress applications.
Their force transferring mechanisms are similar to mechanical expansion anchors. Torque moments are applied to screws which are inserted in plastic sleeves. As torques are applied, the plastic expands the sleeve against the sides of the holes acting as expansion forces.
They act as transferring the forces with mechanical interlocks. This fastening technology is used in steel to steel connections, for instance to connect cold formed profiles. A screw is inserted into the base material with a gas actuated gas gun. The driving energy is provided by firing a combustible propellant as powder form. The insertion provokes the plastic deformation of the base material, which accommodates the fastener’s head, where the force transfer takes place.
When contemporarily tensions and shear loads are applied to anchors, failures occur earlier with respect the uncoupled cases. In current design codes, a linear interaction domain is assumed.
In order to increase load carrying capacities, anchors are assembled in groups, moreover, this allows also to arrange a bending moment resisting connection. For tension and shear load, mechanical behaviors are markedly influenced by the spacing between the anchors and the possible differences in the applied forces.
Under service loads, anchors’ displacements must be limited. Anchor performances under different loading conditions are assessed experimentally. In design phase, displacements occurring under the characteristic actions should not be larger than admissible displacement.
Under seismic loads, there would be a possibility that anchors are contemporarily installed in a crack and subjected to inertia loads proportional both to the mass and the acceleration of attached elements to base materials.
What differs Exceptional loads from ordinary static loads is their rise time. High displacement rate is involved in impact loading. Regarding to steel to concrete connection, some examples consist in collision of vehicles on barriers, connected to concrete base and explosions. Apart from these extraordinary loads, structural connections are subjected to seismic actions, which rigorously have to treat with dynamic approach. Seismic pull out action on anchors can have 0.03 seconds of rise time. On the contrary, in a quasi-static test, 100 second may be assumed as time interval to reach the peak load.
These anchor bolts are driven into the supporting structure, like a wall or the like and rigidly secured therein.
That is another object of the invention to provide stated anchor bolts these can be rapidly and easily driven directly into the supporting structure without boring a hole. These type of anchors are simple in construction, and economical.
These types are sufficiently strong to withstand deformation upon driven into a supporting structure, such as drywall construction, plasterboard, plywood or the like and does not damage surrounding area of supporting structure. With the objects in view, the invention resides in the novel features of arrangement, construction, form and combination of parts.
This described invention, which is claimed and desired to secure by Letters Patent is:
As seen, Anchor bolts are used in variety of places as a fastener. Especially, Anchor Bolts are commonly used in construction field. It is very important to be served by experienced supplier of anchor bolts, because this supremely important field must be managed by professional engineers and experts. Kasko Makine will provide you the right products you need with high quality options. Please contact us for your needs and check our website for further details and other products.