Mechanical Behavior of a Prefabricated Joint for Small-Section Prestressed Concrete Piles Under Tension, Bending and Shear: Full-Scale Tests

Prefabricated pile-cap joints have been applied in concrete pile foundations in waterway revetment structures for decades. However, the mechanical performance of such joints for small-section (≤400 mm) prestressed piles has not been systematically validated, which hinders their application in civil and waterway engineering. This study evaluates this joint system through full-scale tests on six identical 400 mm × 400 mm prestressed concrete pile-cap specimens (C60 pile, C30 joint concrete, HRB400 anchoring bars threaded into embedded steel sleeves) under monotonic tension, bending, and shear, with strain gauges monitoring the response. The results show that the joint sustained a tensile load of 1400 kN, which exceeds the pile’s design value by 52%, a bending moment of 277 kN·m, which is 32% higher than the pile’s ultimate capacity, and a shear force of 680 kN, which reaches more than 2.5 times the design shear, without any occurrence of joint failure. These findings provide the first comprehensive experimental evidence that this prefabricated joint system can effectively transfer tensile, bending, and shear loads in small-section prestressed piles, thereby supporting its safe application in green, industrialized engineering.