Axial-Impact Resistance of CFRP-Confined Ultrahigh-Performance Concrete

Authors：Chen, Zhanbiao; Huang, Liang; Huang, Peiyan; Xie, Jianhe^*

Source：JOURNAL OF COMPOSITES FOR CONSTRUCTION, 2022, 26(5): 04022059.

DOI：10.1061/(ASCE)CC.1943-5614.0001246

• Ultra-high-performance concrete
• Carbon fiber-reinforced polymer
• Confinement
• Dynamic compressive behavior
• Split-Hopkinson pressure bar
• Dynamic strength model

This study investigated the axial-impact resistance of unconfined and CFRP-confined UHPC. External confinement was provided by one to three plies of CFRP wraps with confinement ratios ranging from 0.126 to 0.378. A series of single- and multiple-impact tests was conducted using a o100 mm split Hopkinson pressure bar apparatus at mean strain rates ranging from 25 to 120 s(-1). The dynamic behaviors of the specimens were examined and compared with those under quasi-static loading. The results indicate that the confinement of CFRP can significantly improve the axial-impact resistance of UHPC, exhibiting a strong strain-rate dependency. However, this sensitivity decreases with an increase in the confinement ratio. The dynamic failure modes of the CFRP-confined UHPC are different from those in the static tests, and the CFRP confinement ratio and impact energy determine the impact failure mode. Unlike in unconfined UHPC, a history of multiple impacts results in considerably lower accumulative damage in the confined UHPC. A new model was proposed to estimate the dynamic compressive strength of the CFRP-confined UHPC by considering the coupling effects of the confinement ratio and core concrete lateral inertia.

• Institution
  广东工业大学