The uses of post-expanding bottom anchor bolts and self-expanding bottom anchor bolts are very similar, but there are certain differences in standard usage and practical construction.
The application methods are quite different: although the two are similar in terms of mechanical functions, the distance between them is very large in terms of equipment and methods. The installation method of the rear-reaming anchor bolt is relatively complicated. After the straight hole is drilled, it needs to be reamed separately, and the reaming requires the use of a special reaming drill. Taking the M12 rear-expanded bottom anchor as an example, its expansion size reaches M24, and it is relatively easy to touch the steel bar during installation. The equipment method of self-expanding bottom anchor bolts will be much simpler. On the one hand, it can save a lot of man-hours without separate reaming. On the other hand, it can be equipped with an electric hammer, which is very labor-saving during equipment.
The specifications for sale are different: above, we mentioned the problem of steel bars when we talked about the rear-expanded bottom anchor bolt equipment, which determines that the specifications of the rear-expanded bottom anchor bolt have greater limitations, which is also difficult to find in the market. The number one reason for rear flared bottom anchors of M20 and above specifications. As for the self-expanding bottom anchor, since there is no separate reaming, the probability of hitting the steel bar is relatively small. Therefore, the on-sale specification of self-expanding bottom anchors can even reach M20. However, when using large-scale anchor bolts, try to understand the arrangement of the steel bars in the concrete first, so as to formulate a reasonable drilling plan.
The safety functions of the two: first discuss the different methods of self-expanding bottom anchor bolts on the market, mainly divided into two types, one is the self-expanding bottom anchor bolt using the diamond cutter head, and the other is the self-expanding bottom anchor bolt by adjusting The method of pulling height, inclination and sleeve blocking comes from the reamed anchor bolt. The hole reaming effect of the first type is better than that of the second type, but the price is expensive, and the one-time use of the diamond bit will inevitably lead to waste. The second type of anchor bolts that end the self-expanding bottom with mechanical structure can generally only partially cut the concrete during equipment, which cannot achieve the effect of the previous self-expanding bottom anchor bolts, but the construction is simple.
Then, although the construction of the bottom-expanding anchor is more complicated, the pre-expanding operation can make the anchor expand more in place after the equipment, and the anchor will not be directly pulled out during the pull-out experiment. Small specifications such as M12 rear-expanded bottom anchor bolts and self-expanded bottom anchor bolts have very close tensile forces, but when the specifications are large, there is some distance between the mechanical functions of the two. However, the actual demand for M12 anchor bolts can account for more than 60%.
The difference with the expansion anchor bolt: The expansion anchor bolt is a kind of mechanical anchor bolt that forms a corresponding anchoring effect through the friction force between the special mechanical structure and the concrete hole wall after the equipment is in place. Anchor bolts, etc. The stress effect of the expansion anchor bolt will be larger depending on the type of anchor bolt, but it is difficult for the foundation to reach the level of the rear expansion bottom anchor bolt and the self expansion bottom anchor bolt. It is best to understand the expansion bottom anchor bolt and expansion anchor bolt. The difference between the anchor bolts can determine which anchor bolts should be used during construction.
shellyn-anchor.com