Experimental Study on Dynamic Response of Nano-modified Ultra-high Performance Concrete Slabs Under Explosion Loads

In order to investigate the dynamic response of nano-modified ultra-high performance concrete (UHPC)slabs under explosion loads,a series of UHPC targets were designed and subjected to close-in explosion impacts. The key mechanical parameters of the targets under explosion loads were studied and analyzed by using the dynamic test system and relevant sensors to collect signals,such as displacement,strain and acceleration. The results show that the anti-explosion performance of series UHPC slabs under two explosion impacts is significantly better than that of ordinary high-strength concrete. The UHPC slabs reinforced by both steel fibers (SF)and carbon nanotubes (CNTs)(i. e.,SF0. 5CNT-UHPC and SF1. 0CNT-UHPC)show excellent deformation resistance ability and structural stability. With the increase of SF content,the maximum mid span deflections,strain peaks and acceleration peaks of UHPC slabs significantly decrease,and the corresponding damage degrees reduce. The elastic displacement response of SF0. 5CNT-UHPC and SF1. 0CNT-UHPC slabs are theoretically calculated by using the equivalent single-degree-of-freedom analysis. The theoretical calculation results of the maximum deflection at the midspan are close to the measured values,and the errors of the above two slabs are 13. 5% and 8. 7%,respectively. It is concluded CNTs and steel fibers significantly improve the strength,stiffness and crack resistance of UHPC by suppressing the defects at different scales,which display synergistic reinforcement effects on UHPC. © 2024 Cailiao Daobaoshe/ Materials Review. All rights reserved.