Materials- Design & Construction
337142 - Experimental Study of NEW RC Exterior Beam-Column Joint made of Highly-Flowable Strain Hardening Fiber Reinforced Concrete
Friday, April 20
11:00 AM - 12:30 PM
The concept of New RC, which is upgrade of concrete and reinforcement strength, was proposed in Japan in 1995. The purpose of New RC project was aimed to reduce the member section sizes and increase the available space of high rise buildings by using high strength concrete (f’c > 70 MPa) and high strength rebars (fy > 685 MPa). Material consumptions and member sections can be further reduced owing to the upgrade of strength. However, the nature of brittleness of high strength may also cause early cover spalling and other ductility issues. Traditional techniques for increasing the ductility of reinforced concrete members have relied on increasing the amount and number of lateral stirrups, but constructability decreases. Highly flowable strain hardening fiber reinforced concrete (HF-SHFRC) has excellent workability in the fresh state and exhibits the strain-hardening and multiple cracking characteristics of high performance fiber reinforced cementitious composites (HPFRCC) in their hardened state. The objective of this study is to investigate the feasibility of implementing HF-SHFRC in New RC beam-column joints as an alternative of transverse reinforcements. Five full-scale exterior beam-column joints, including two specimens with intensive transverse reinforcements and three specimens made of HF-SHFRC without any stirrup, are tested. Test results show that the HF-SHFRC specimens perform as well as specimens with intensive transverse reinforcements regarding failure mode, ductility, energy dissipation and crack width control. Integration of precast systems and HF-SHFRC can assure construction qualities and further diminish labor work and give infrastructure longer service life, and eventually lower the life-cycle cost.