Dynamic Compressive and Splitting Tensile Characteristics of Rubber-Modified Non-Autoclaved Concrete Pipe Piles

Non-autoclaved concrete pipe piles are gaining attention as an environmentally friendly alternative to autoclaved concrete pipe piles. The purpose of this study was to investigate the changes in the impact resistance of a non-autoclaved concrete pipe pile with the addition of rubber. To this end, various volume fractions of rubber particles were used to replace the fine sand in the nonautoclaved pipe pile concrete (0%, 5%, 10%, 15% and 20%). The dynamic and static mechanical responses of rubber-modified non-autoclaved pipe pile concrete were explored through quasistatic and dynamic compression and splitting tensile tests. The results showed that (1) The tensilecompression ratio of the rubber-modified non-autoclaved pipe pile concrete increased with the rubber content, and the brittleness of non-autoclaved concrete was improved by adding rubber. (2) When subjected to impact load, rubber particles could absorb some of the impact energy, reduce the impact load on the aggregate, and prevented the aggregate from being crushed. (3) The impact toughness index and energy consumption ratio of non-autoclaved pipe pile concrete increased with the increase of rubber content. When the rubber content was 10%, the impact toughness index and energy consumption ratio of non-autoclaved pipe pile concrete were 52.2% and 51.2% higher than those of non-autoclaved pipe pile concrete without rubber particles, respectively, and its impact resistance was the best. The impact resistance of rubber-modified non-autoclaved pipe pile concrete was better than that of traditional autoclaved pipe pile concrete, and met the mechanical performance requirements of prestressed high-strength concrete pipe pile. It could be used as a new prestressed high-strength concrete pile material, which helped to reduce energy consumption in the production process of piles. The study provided parameter basis for the subsequent drop hammer impact test and numerical simulation of pipe piles.