A self-drilling anchor bolt is a product that can integrate drilling, grouting, and anchoring. Its construction process is simple, the construction efficiency is high, the anchoring effect is good. It is widely used in tunnels, mines, and construction projects. It plays a key role in engineering. Since the service life of self-drilling anchor bolts directly affects the stability and safety of underground engineering, it needs to be paid attention to.
How long is the service life of self-drilling anchor bolt?
The service life of self-drilling anchor bolts is related to the conditions of the formation and the material, with those featuring an additional anti-corrosion treatment boasting a longer lifespan. In geotechnical anchoring projects, the level of corrosion protection and measures for anchor bolts should also be determined according to the designed service life of the anchor bolts while also considering the corrosive nature of the construction layers.
General support engineering includes temporary support, semi-permanent support, and permanent support. For short-term support projects lasting up to two years, non-corrosive anchors are suitable. For semi-permanent support projects ranging from two to under five years, choose between hot-dip galvanized or epoxy-coated anchors based on environmental corrosion factors. For permanent support projects exceeding five years, double-corrosive anchors are necessary.
Hot-dip galvanizing anchor bolts are suitable for corrosive environments such as acid and alkali fog or where geotechnical engineering requires a high service life of anchor bolts. The construction environment is complex.
Epoxy coating anchor bolts are suitable for situations with exposure to seawater erosion, in settings where geological formations and groundwater contain sulfides and chlorides, and when the environment has stray currents or corrosive elements.
Double anti-corrosion anchor bolts are first treated with hot dip zinc and then sprayed with an epoxy coating so that the anchor bolts have better anti-corrosion properties, higher safety factors, and longer service life with double anti-corrosion. Double anti-corrosion anchor bolts are suitable not only for resisting standard chemical erosion but also for the acidic environment and electrochemical erosion of stray currents.
What are the factors that affect the service life of self-drilling anchor bolts?
Environmental factors
Environmental factors primarily consist of the self-drilling anchor bolt’s surrounding corrosiveness, soil pH values, temperature, humidity, etc., including the climate and geography of the construction site. For example, in coastal regions susceptible to seawater splash or sea salt infiltration, the service life of self-drilling anchor bolts tends to be shorter; if the environment is dry and free of corrosive media, the service life of self-drilling anchor bolts is 2~3 times longer than that in the wet or corrosive media environment.
Grouting material factors
The grouting material of self-drilling anchor bolts generally chooses pure cement slurry. The admixture of minerals such as fly ash can reduce the alkalinity of cement paste, change the endospore structure of cement paste and improve its compactness of cement paste. It can prevent the infiltration of external corrosive media, oxygen, and moisture, thus improving the anti-corrosion ability and durability of the self-drilling anchor bolt and prolonging its service life.
Protective layer factors
Methods to extend the service life of self-drilling anchor bolts
Select high-quality materials
Select reliable self-drilling anchor bolt materials to ensure that they comply with relevant standards and guarantee service life from the source.
Rational design
According to the actual engineering load conditions, reasonable design of self-drilling anchor bolts, to ensure that it has the sufficient load-bearing capacity, is not to be overused.
Regular testing and maintenance
Regularly test the self-drilling anchor bolt and find problems in time for maintenance and repair to avoid potential failures evolving into serious problems.
Control the construction quality
In the construction process, strengthen quality control to ensure that the self-drilling anchor bolt is right and firmly installed at the designated position.
Strengthen environmental protection measures
Special environmental conditions require anti-corrosion, waterproofing, and other measures to slow down the process of self-drilling anchor bolt corrosion.
As an important geological engineering support material, self-drilling anchor bolts can effectively prolong the service life of self-drilling anchor bolts through various measures, thereby improving their application performance in underground engineering. However, with the continuous advancement of technology and the continuous accumulation of engineering practice, it is believed that self-drilling anchor bolts will have better performance in terms of service life in the future.
