Page 11 - Open-Access-June-2020

TECHNICAL PAPER

Table 3: Bond Behavior Between Reinforcement and ECC

sl. dimensions diameter of emBedded
no. referenCes (b×d×h)*(mm) Bar (db) (mm) length (mm) oBjeCtive oBservation
1. Kanakubo and 182×182×91 13 52 To investigate the bond- ECC exhibits enhanced bond
Hosoya [47] splitting strength between strength in both pullout and
ECC and reinforcing bars by beam bond test than that of
conducting pullout bond test conventional concrete.
and beam bond test.
2. Lee et al. [48] i) 250×195 13 65 & 260 To investigate the bond-slip ECC showed 14% increased
ii) 250×390 behavior of short and long local bond stress in
steel reinforcement embedded short reinforcement than
in well-confined conventional conventional concrete.
concrete and ECC.
3. Cai et al. [50] i) 150×150×300 16 220 & 80 To investigate the bond Deformed steel rebar showed
ii) 150×150×150 behavior of deformed steel much higher bond strength in
rebars in ECC and concrete. ECC than concrete.
* (b- breadth, d- depth & h- height)

Bandelt et al. investigated the bond behavior of ECC and Yuan et al. investigated the behavior of RECC columns under
[49]
[51]
conventional concrete. Beam specimens along with lap splices two different eccentric compression. Further, they conducted
were tested for its bond-slip behavior. The study reported that, parametric studies to investigate the effects of the matrix types,
the ECC specimens showed only negligible increase in strength longitudinal reinforcement ratios, ECC compressive strength
than conventional concrete due to the addition of cover and ECC tensile ductility. The study reported that spalling was
thickness and confinement. not observed in RECC columns due to its fiber bridging property
and its failure pattern differ significantly from RC columns. They
Cai et al. investigated the bond behavior of deformed steel
[50]
rebars in ECC and concrete. The study reported that, the also concluded that with increase in load-eccentricity ratio, the
deformed steel rebar showed much higher bond strength load carrying capacity of RECC columns increased significantly
in ECC compared to concrete even though the compressive when compared to RC columns. In addition, compared to RC
strength of ECC is lower than concrete. column the RECC column showed enhanced ductility due to the
larger ultimate strain of ECC.
5. BEHAVIOR OF COLUMNS
Wong investigated the ECC square short columns confined
[52]
It is expected that the RECC column exhibit significant by steel pipes and compared against unconfined ECC, concrete
behavioral changes in load carrying capacity, deformation square short columns. The study reported that the strength
and ductility due to the pseudo- strain-hardening and tensile degradation was gradual in case of unconfined ECC columns
load carrying capacity of ECC. Nevertheless, very few research unlike unconfined concrete columns. Compared to unconfined
studies (see Table 4) have investigated the structural response of ECC columns, the confined ECC columns exhibits a small
RECC columns as the prime interest. enhancement in the confined strength.

Table 4: Behavior of ECC Columns

sl. dimensions
no. referenCes (b×d×l) (mm) oBjeCtive oBservations
*
1. Yuan et al. [51] 200×250×1200 To investigate the performance of RECC i) For eccentricity of 40 and 120mm, the ultimate
columns under eccentric compression. strength of RECC columns increased 35.6% and 31.8%,
respectively with respect to RC column.
ii) The crack width of RECC and RC columns at peak load
were 60µm and 2mm, respectively.
2. Wong [52] 100x100x300 To investigate the performance of Both unconfined and confined ECC columns showed
confined and unconfined ECC square enhanced behavior than unconfined and confined concrete
columns. column.
* (b-breadth, d-depth & l-length)

12 The IndIan ConCreTe Journal | June 2020