Study on the Dynamic Performance and Damage Evaluation of Rubber-Modified Non-Autoclaved Concrete Pipe Piles under Axial Drop Hammer Impact

Abstract

In order to improve the weak impact resistance of non-autoclaved concrete pipe piles, this study replaced sand in the concrete with rubber particles of different volume contents to obtain rubber-modified non-autoclaved concrete pipe piles (with volume contents of 0%, 5%, 10%, and 15%). The dynamic impact response characteristics of rubber-modified non-autoclaved concrete pipe piles were obtained through large-scale axial hammer impact experiments. The results indicate the following. (1) Non-autoclaved concrete pipe piles without rubber additives were prone to expansion deformation instability under impact. When the rubber content was 10%, the expansion deformation of the piles was the weakest, and the state was the most stable. (2) When the impact energy exceeded 48 kJ, the deformation energies of piles with 5% and 10% rubber contents significantly increased. (3) The damage levels of the piles after hammer impact were classified into four grades: no damage, mild damage, moderate damage, and severe damage. When the impact energy was greater than or equal to 48 kJ, rubber-modified non-autoclaved concrete pipe piles exhibited damage. The zone with no damage for piles with 10% rubber content was the smallest, making it less prone to damage under impact loads. The rubber-modified non-autoclaved concrete pipe piles with 10% rubber content not only had excellent impact resistance but also utilized the advantages of being environmentally friendly and energy-saving. They filled a certain knowledge gap in green building materials.