As the only two kinds of bottom expanding anchor bolts on curtain wall, the post expanding bottom anchor bolt  the self expanding bottom anchor bolt are similar in use, but they are different in standard usage  practical construction.

The application methods are quite different

Although the mechanical functions of the two are similar, the distance between them is very large in terms of equipment. The equipment method of post reaming anchor bolt is messy. After drilling straight hole, it is required to ream independently,  special reaming bit is required. For example, the expansion standard of M12 rear belled anchor bolt reaches M24,  the reinforcement is slightly touched during equipment. On the one hand, there is no need to expand the hole alone to save a lot of working hours. On the other hand, it can be equipped with electric hammer to equipment, which is very labor-saving.

The standards on sale are different

As we mentioned above, we briefly encountered the problem of reinforcing steel bar when we mentioned the equipment of rear enlarged bottom anchor bolt. Therefore, the standard of rear expanded bottom anchor bolt has great limitations. This is also the primary reason why it is difficult to find the rear expanded bottom anchor bolt with M20  above standard in the market. As for the self expanding bottom anchor bolt, the probability of meeting the reinforcement is relatively small because there is no independent reaming. Therefore, the sale standard of self expanding bottom anchor bolt can even reach M20. However, when using large standard anchor bolts, it is necessary to understand the arrangement of reinforcement in concrete first, so as to make a reasonable drilling plan.

The safety function of the two

First of all, we will discuss the different methods of self expanding bottom anchor on the market, which are mainly divided into two types: one is the self expanding bottom anchor bolt with diamond cutter head; the other is the anchor bolt  reaming hole by adjusting the withdrawal height, slope  sleeve blocking. The first kind has better reaming effect than the second one, but it is expensive, so it is inevitable to waste the one-time use of diamond bit. The second type of anchor bolt with self expanding bottom can only partially cut the concrete when the equipment is used, which can  achieve the function of the former one, but the construction is simple.

However, the pre reaming operation can make the anchor bolt expand in place after the equipment,  the anchor bolt will  be directly pulled out during the pull-out test. The tensile force of small standard such as M12 rear belled anchor bolt  self expanding bottom anchor bolt is very close, but when the standard is large, there is some distance between the mechanical functions of the two. However, the actual requirement of anchor bolt of M12 can account for more than 60%.

Difference between expansion anchor bolt  expansion anchor bolt

Dilation anchor bolt is a kind of mechanical anchor bolt which forms corresponding anchoring effect through special mechanical structure  friction force of concrete hole wall after the equipment is in place. The representative anchor bolt includes anchor bolt, internal force anchor bolt, etc. Due to the different types of anchor bolts, the force acting on the expanding anchor bolt will be larger, but it is very difficult to reach the level of the rear expanding anchor bolt  the self expanding bottom anchor bolt. We'd better understand the difference between the expanded bottom anchor bolt  the expansion anchor bolt before we can judge which anchor should be used in the construction.

Some project construction personnel do  know the bottom expansion anchor bolt, often mistakenly use the expanded bottom anchor bolt as the expansion anchor bolt, which is really dangerous. In the early stage of construction, we hope that all manufacturers can provide corresponding technical disclosure together with the products sold, so that the construction personnel can understand the application method of products  the importance of curtain wall engineering safety.