Experimental and theoretical study on bond behavior of helically wound FRP bars with different rib geometry embedded in ultra-high-performance concrete. (15th April 2023)

• Record Type: Journal Article
• Authors: Liang, Kun; Chen, Lijie; Shan, Zhiwei; Su, R.K.L.
• Is Part Of: Engineering structures. Volume 281(2023)
• Publication Date: 2023-04-15
• Subjects: Bond behavior -- FRP bars -- UHPC -- Surface condition -- Bond strength model; Structural engineering -- Periodicals; Structural analysis (Engineering) -- Periodicals; Construction, Technique de la -- Périodiques; Génie parasismique -- Périodiques; Pression du vent -- Périodiques; Earthquake engineering; Structural engineering; Wind-pressure; Periodicals; 624.105
• DOI: 10.1016/j.engstruct.2023.115769
• Languages: English
• ISSNs: 0141-0296

Abstract

Highlights: Bond strength of FRP bars in UHPC is greatly affected by rib geometry. Rib geometry and materials properties of FRP bars dominates the bond strength. The existing codes cannot be used for FRP bars embedded UHPC directly. A bond strength model that accounts for rib geometry is established. Abstract: Fiber reinforced polymer (FRP) bar reinforced ultra-high-performance concrete (UHPC) members have attracted wide interest due to their excellent durability and mechanical properties. Determining bond strength is of great importance to the design of FRP bar reinforced UHPC members. This study investigates the effects of bar type, concrete type and rib geometry on the bond behavior of helically wound FRP bars embedded within UHPC. Pull-out tests on a total of 48 specimens with three types of concrete (0%, 1% and 2% steel fiber content), three types of bar (steel, basalt FRP and glass FRP) and three types of surface condition (smooth, shallow ribbed and deep ribbed) have been conducted. The results show that the bond strength of FRP bars embedded within UHPC is greatly affected by rib height. Indeed, FRP bars with deep ribs can reach a bond strength comparable to that of ribbed steel bars. A novel bond strength model for FRP bars embedded within UHPC, considering the effect of rib geometry, has been proposed and validated by the experimental results and existing data in the literature.