Experimental Study On Fire Behavior Of The Inorganically Post-installed Rebar Connection

As one of post-installed fastenings, post-installed rebars are widely used in reinforcement and reconstruction engineering. At present, the organic anchorage technology is used mainly; while the research and application of the inorganic anchorage technology is less. As we all know, in practical engineering many post-installed rebar connections may be at the risk of fire. Considering the inorganic material having a good high temperature performance, the inorganic anchorage technology is bound to get a wider range of applications, after their own shortcomings are overcome.A serial of real fire tests has been conducted to study the fire resistance properties of the post-installed rebar connection with inorganic adhesive. Three different anchorage depths of anchorage adhesive are considered in this test. Loads were applied through lever and remained constant throughout the whole process of the tests before temperature loads applied. The specimens were heated up according to the ISO834heating curve until the deflection of the beams reached the point of failure.Through the tests, the temperature distribution law of organic and inorganic anchorage flexural members is explored, as well as failure mechanism of under coupling action of load and fire temperature. The test results show that anchorage depth and types of anchorage glue has a great influence on the mechanical properties of the anchorage beams in fire. Beams using organic glue failed suddenly with the anchorage collapse, and showed a poor fire endurance. While using inorganic glue, anchorage collapse did not happen at some certain anchorage depth, in other words, their mechanical behaviour of the inorganic anchorage beams in fire were the same as that of the RC beams.The main research contents of this paper are as follows: (1) based on the relative research work which are studied by domestic and foreign researchers, factors of anchorage performance and development status of structural adhesive are summarized.(2) Through a serial of real fire tests, in which different anchorage depth and different types of anchorage glue are involved, resistance limit of specimens and temperature field of the anchorage beams are measured. And beams’deflection at mid-span and the high temperature strain of longitudinal bars are also recorded.(3) Through the collation and analysis of test data, failure mode and slip variation of anchorage system under high temperature is further analyzed. By comparing different anchorage depth, the influence of anchorage depth on fire behavior was discussed in this paper. On the other hand, by comparing different types of anchorage glue, the influence of different types of anchorage glue on fire behavior was also discussed in this paper.(4) Summary of the studies made in this article is presented, and this article also analyzes the shortcomings. However it is pointed out that finite element analysis is quite necessary. The article finally has made the forecast to the future development tendency of post-installed fastening technology.