Uranium solid performance test of butterfly rebar-corrugated pipe slurry hoe connection

To provide a theoretical basis for the application of spiral reinforcement-corrugated tube grout-pin connection in prefabricated structures, 21 pin-fixed pull-out specimens were designed and manufactured. Through unidirectional pull-out tests, the failure mode, load-displacement curve and the influence of different influencing factors on the bond pin-fix strength of the specimens were analyzed. The bond strength calculation formula of spiral reinforcement-corrugated tube grout-pin connection was fitted, and the recommended value of the pin-fix length was proposed. The test results show that the failure modes of the specimens are mainly steel bar pull-out, crack pull-out, steel bar breakage and rib breakage; the bond strength decreases with the increase of pinning length and steel bar diameter; with the increase of corrugated pipe diameter, the bond strength changes nonlinearly with the steel bar diameter, and the pinning performance is best when the diameter is 50 mm and 60 mm; the average ultimate bond strength increases with the increase of grouting material strength and the pinning length can be further shortened to 5 d; in engineering applications, when the steel bar diameter is not greater than 16 mm, it is recommended that the pinning length be 5 d∼7 d, the aperture ratio be 2.5∼4.28, and when the grouting material strength is , the pinning length should not be less than fcu≥80MPa5 d.