Why are chemical anchor bolts used for the steel structure construction of loft apartments?

Why not use expansion bolts instead of chemical anchor bolts for the steel structure construction of loft apartments?
1. Chemical anchor bolt: It is a high-strength anchor bolt made mainly of vinyl resin as the main raw material, and was originally called a chemical anchor bolt. Chemical anchor bolt is a new type of anchor bolt that emerged after expansion anchor bolt. It is fixed to the concrete substrate by using a specially made chemical adhesive to bond the screw;

Expansion bolts: Expansion screws are generally referred to as metal expansion screws. The fixation of expansion screws is achieved by using wedge-shaped slopes to promote friction and gripping force during expansion, achieving a fixing effect. Generally used for fastening protective railings, awnings, air conditioners, etc. on materials such as cement and bricks. But its fixation is not very reliable, and if there is significant vibration in the load, it will become loose and loose over time.

2. Principle of fixing expansion bolts: Expansion bolts mainly rely on the opening of the expansion pipe to generate high friction with the concrete, which is caused by human factors. Sampling for tensile testing is also useless;
The fixing principle of chemical bolts: Chemical bolts are formed by punching holes with a punching machine, then filled with chemical slurry, and the bolt rod is inserted to form an anchoring effect.

3. Characteristic zones of chemical bolts and expansion bolts:
Chemical bolt characteristics: no stress concentration (no expansion stress), not affected by external interference, with acid and alkali resistance, low temperature resistance, aging resistance, good heat resistance, good flame retardant performance, good welding resistance, and good seismic resistance!
Characteristics of expansion bolts: With stress concentration and poor seismic performance, stress concentration occurs in the concrete, greatly increasing the probability of concrete cracking and failure.