Flexural behavior of reinforced concrete beams strengthened by HDC and RPC. (10th November 2018)

• Record Type: Journal Article
• Authors: Deng, Mingke; Ma, Fudong; Ye, Wang; Li, Fangyuan
• Is Part Of: Construction & building materials. Volume 188(2018)
• Page Start: 995
• Page End: 1006
• Publication Date: 2018-11-10
• Subjects: fc, fdc, fpc Uniaxial compression strength of the NC HDC and RPC (MPa) -- fcu Cube compression strength of the NC (MPa) -- ft, fdt, fpt Tensile strength of the NC HDC and RPC (MPa) -- εtc, εdtc Tension cracking strain of the NC and HDC (mm/mm) -- εpt 0 Peak tension strain of RPC (mm/mm) -- εtu, εdtu Ultimate tension strain of NC and HDC (mm/mm) -- ε0, εdc0, εpt0 Peak compression strain of NC HDC and RPC (mm/mm) -- εu, εdu Ultimate compression strain of NC and HDC (mm/mm) -- Pα, Py, Pu The cracking, yielding and ultimate load (kN) -- Δα, Δy, Δu The cracking, yielding and ultimate displacement (mm) -- µΔ Displacement ductility coefficient -- α1, α2 The stiffness change point determination parameters of the HDC stress-strain curve: α1 = 0.95, α2 = 0.9 -- εdm, εpm Compression marginal strain of HDC and RPC -- αd, αp Equivalent rectangular stress coefficient of HDC and RPC -- βd, βp Equivalent rectangular stress block depth coefficient of HDC and RPC -- fy, fy Tension and compression yielding strength of a steel bar (MPa) -- As, Às Section area of the tension and compression steel bar (mm2) -- Fexp Peak load on test specimens (kN) -- Fthy Theoretical calculation values of the flexural capacity of specimens (kN); Highly ductile fibre reinforced concrete (HDC) -- Reactive powder concrete (RPC) -- Layer -- Flexural behavior -- Flexural capacity; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2018.08.124
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: Strengthening in the tension zone can improve the flexural capacity. Too many steel bars added may lead to similar over-reinforced beam failure. The beams strengthened in the compressive zone exhibit higher ductility. Strengthening effect is more obvious as the increase of reinforcement ratio. Abstract: Highly ductile fibre reinforced concrete (HDC) and reactive powder concrete (RPC) are characterized by tensile strain-hardening behavior and ultrahigh strength, respectively. This paper investigates the flexural behavior of reinforced concrete beams strengthened by HDC and RPC in the tension and compressive zones. The crack distribution, failure pattern, load-displacement responses, flexural capacity analysis, displacement ductility and concrete strain are investigated. The experimental results from monotonic loading tests on the specimens show that the flexural capacity of specimens strengthened by an HDC layer in the tension zone was notably increased and that the specimens strengthened by an HDC or RPC layer in the compressive zone exhibit much higher ductility than the control concrete beams. Moreover, the proposed calculation method of flexural capacity is more accurate, consistent and conservative.