Shear strengthening of reinforced concrete beams with high strength strain-hardening cementitious composites (HS-SHCC)

  • PDF / 1,711,204 Bytes
  • 15 Pages / 547.087 x 737.008 pts Page_size
  • 9 Downloads / 215 Views

DOWNLOAD

REPORT


(0123456789().,-volV) ( 01234567 89().,-volV)

ORIGINAL ARTICLE

Shear strengthening of reinforced concrete beams with high strength strain-hardening cementitious composites (HS-SHCC) Jiaying Wei . Chang Wu

. Yixin Chen . Christopher K. Y. Leung

Received: 2 October 2019 / Accepted: 16 July 2020 Ó RILEM 2020

Abstract Strain-hardening cementitious composite (SHCC) was widely recognized as a material that possesses great potential in the repair and strengthening of reinforced concrete (RC) structures. SHCC can usually achieve high ductility with multiple cracking behavior and it also has excellent durability. Moreover, high tensile strength can also be achieved with proper mix design. In this study, conventional RC beams with shear span-to-depth ratio of 1.5:1 and 2.5:1 were cast first, while high-strength SHCC were then cast as thin patches on lateral surfaces of the RC beams to serve as the strengthening layers. The beams were subject to four-point bending test to obtain their ultimate shear capacities. It was observed from the test results that the ultimate shear capacity of strengthened RC beams increases evidently compared to the reference beams. Upon ultimate shear failure, no

spalling of surface concrete occurred as it was restrained by the strengthening layers with the formation of stable multiple fine cracks. A finite element model was constructed to simulate the experimental tests. The results of FEM analysis correlated well with experimental results. A numerical parametric study was then carried out to evaluate the influence of the thickness of HS-SHCC layer and the shear span-todepth ratio. This study concludes the feasibility of the use of high strength SHCC in shear strengthening of RC structures. Keywords SHCC  Structural strengthening  Shear  High tensile strength

1 Introduction J. Wei  Y. Chen  C. K. Y. Leung Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong SAR, People’s Republic of China e-mail: [email protected] Y. Chen e-mail: [email protected] C. K. Y. Leung e-mail: [email protected] C. Wu (&) School of Civil Engineering, Southeast University, Nanjing 211189, People’s Republic of China e-mail: [email protected]

Concrete has undergone several important phases as a structural material in the construction industry. In the early 1900s and around 1940s, steel reinforced concrete and prestressed concrete were established to be important construction materials. High strength concrete was commercialized around 1970s, making possible the construction of taller, longer and bigger infrastructures [1]. Due to increase in design load demands, seismic retrofitting or durability problems caused by degradation of construction materials over time, some of the existing structures no longer comply

102

Page 2 of 15

with current design standards or even become functionally obsolete. It is obvious that complete replacement of all such structures would be infeasible in terms of both time and cost. Strengthening and retrofitt

Data Loading...