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SEISMIC BEHAVIOR OF PRECAST REINFORCED CONCRETE WALLS
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SEISMIC BEHAVIOR OF PRECAST REINFORCED
CONCRETE WALLS
Yaw-Jeng Chiou 1 Yuh-Wehn Liou2 Chin-Chi Huang 3 and Fu-Pei Hsiao4



ABSTRACT
This study experimentally investigates the seismic behavior of precast reinforced concrete walls by test of
large-scale specimens. The parameters of connected steel cover plate, orientation of wall reinforcements,
steel ratio of wall, and strength of concrete were studied. The results show that the precast reinforced
concrete wall can effectively increase the earthquake resistance of structures and protect the structural
frame. The performance of the precast reinforced concrete wall can be fully developed by using connected
steel cover plates with two channel plates which were fixed by M16 chemical anchors. The modified
conventional reinforcement with more steel at the corners produces better performance than the other
orientations. The larger steel ratio and stronger concrete also definitely increase the earthquake resistance
of structures.
Keywords: precast reinforced concrete wall, large-scale test, earthquake resistance



INTRODUCTION
Framed shear walls are extensively used as the components of earthquake resistant buildings.
Previous researches (Zhang and Wang 2000; Palermo and Vecchio 2002; Hidalgo et al. 20002;
Greifenhagen and Lestuzzi 2005) have demonstrated that framed shear walls behaved with higher
strength and lower ductility. The hysteresis loops of mid-rise and low-rise walls were also
characterized by obviously pinched shapes. The results presented by Sittipunt et al. (2001) showed
that the high-rise framed-walls with diagonal reinforcement displayed rounded hysteresis curves, and
more energy was dissipated by the walls with diagonal reinforcement. The authors (Chiou et al. 2006)
also found that the mid-rise framed-walls with diagonal reinforcement displayed rounded hysteresis
curves and failed due to crushing at the bottom of boundary columns.
Adding the concrete walls to frame structural system sounds an efficient retrofit method for reinforced
concrete structures. However, the retrofit of reinforced concrete structures by using cast-in-place
concrete walls takes a lot of site formwork and labor. Recent research has shown that precast concrete


walls can be used as part of the lateral force resisting system (Kurama et al. 1999, Crisafulli et al.
2002). The incorporation of precast concrete components has the advantages of high quality control,
reduction of site formwork and labor, increased speed of construction, and overall economy (Crisafulli
et al. 2002).
The framed shear walls frequently induce failure of boundary columns (Chiou et al. 2006). The
development of a retrofit method with most of the energy dissipated by the wall, and the structural
frame system remains safe sounds like an innovative strategy. The precast concrete walls separate
from the boundary columns, and the forces in the wall will not further transfer to columns. The
retrofit of reinforced concrete structures by precast walls which are used as part of the lateral force
resisting system seems to be an alternative attractive method. However, the performance of precast
concrete walls will highly depend on the frame-wall connections which determine the loads transfer
from frame to wall panel.
This study experimentally investigated the seismic behavior of precast reinforced concrete walls. A
new vertical load experimental system was proposed to improve the conventional vertical load applied
system. Nine large scale specimens subjected to both cyclic lateral force and vertical load were tested.
The parameters of connected steel cover plate, orientation of wall reinforcements, steel ratio of wall,
and strength of concrete were studied.


EXPERIMENTAL INVESTIGATION

1. Experimental Setup
Figure 1 shows the schematic configuration of the test setup. Each specimen was bolted at the steel
foundation, which was then connected to the strong floor. Both vertical load and cyclic lateral force
were applied to the specimen. A new vertical load experimental system was proposed to improve the
conventional system. This new system was designed with lever and pulley block (Figures 1 and 2). A
manually operated hydraulic jack with a loading capacity of ± 1500kN and a stroke of ± 200mm
supplied the lateral force. The lateral displacements were measured by linear variable differential
transformers (LVDT) and the force was measured by load cell. The experiment was displacement
control, and its displacements were 1mm, 2.5mm, 5mm, 10mm, 20mm, 30mm, 40mm, 50mm, 60mm,
and 70mm, respectively. Each displacement was repeated twice the amount of loading. The measured
force and displacement were collected by TDS-302 data logger. The experiment was monitored by the
load-displacement curve.



2. Design of Vertical Load Experimental System
The hydraulic actuator is frequently used in the conventional vertical load applied system. However,
it is not an easy task to safely fix the actuator during test. Referring to Figures 1 and 2, a new vertical
load experimental system was designed with lever and pulley block in this study. There are two pulley
block systems applied to both left and right columns. Each column has 8 pulley blocks at one side of
the specimen and each block connects to the steel cover for vertical load transfer (Figure 2a) via steel
bar. The cable passes the pulley, and the load is transferred to steel bar and specimen eventually. The
force in the steel bar is measured by strain gage. The friction force may exist between cable and the
contacted surface of pulley.
Due to the effect of friction, the initial distribution of vertical force is trapezoid. However, the
distribution of vertical force changes repeatedly from trapezoid to uniformly distribute and vice versa
when the lateral force varies. It is found that the distribution of vertical force is nearly uniform in each
loading cycle.



3. Design of Specimens
The walls were designed with conventional reinforcements (Figures 3a1 and 3a2), modified
conventional reinforcements with more steel at four corners (Figures 3b1 and 3b2), and radial
reinforcements (Figures 3c1 and 3c2). The reinforcements were welded to the drilling holes of steel
cover plates. The connected steel cover plates were designed with two channel plates and one
rectangular plate with an opening, and the M16 chemical anchors were used to transfer the force
between the wall panel and the frame. Nine specimens including four walls with conventional
reinforcements (PMLL1a, PMLL1b, PMHL1b, PMLH1b), two walls with modified conventional
reinforcements (PMLL2b, PMHL2b), and three walls with radial reinforcements (PMLL3a, PMLL3b,
PMHL3b) were tested. The first letter P represents precast; the second letter M represents the mid-rise
wall; the third letter L and H represent lower and higher concrete strength; the fourth letter L and H
represent lower and higher steel ratio; the fifth numbers 1, 2, and 3 represent conventional
reinforcements, modified conventional reinforcements, and radial reinforcements, respectively; the last
letter a and b represent one rectangular plate with an opening and two channel plates of connected
steel cover plates. The dimensions and reinforcement layout of representative specimens are presented
in Figure 3. Table 1 summarizes the properties of all specimens.


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RESULTS AND DISCUSSION

1. Performance of precast walls
Figure 4 shows the crack patterns and load-displacement curves of tested specimens, respectively.
The experimental results are summarized in Table 2. The crack patterns of Figure 4 demonstrate that
the loads have transferred from frame to wall panel. The load-displacement curves in Figure 4 show
that the behavior of precast specimens is similar to cast-in-place specimens (Chiou et al. 2006). There
is also a pinching effect in the load-displacement curves. However, the crack patterns of precast
specimens are obviously different from cast-in-place specimen. Due to the extra energy dissipation of
chemical anchors, the ultimate displacement and energy dissipation of precast specimens are found to
be larger than the comparable cast-in-place specimen. The proposed precast walls are demonstrated to
be capable of increasing the earthquake resistance of reinforced concrete structures.



2. Effect of connected steel cover plate
The connected steel cover plates are found to significantly affect the crack patterns and behavior of
precast specimens. Referring to Figure 4a1, it is found that there are some minor cracks at the top and
bottom of columns of specimen PMLL1a. However, there is no observable diagonal crack in the wall.
The shear forces sound don’t completely transfer to this precast wall and its performance is not fully
developed. Due to the stress concentration around the open region of connected steel cover plate, the
local cracks occurred in the left and right bottom corners of wall and the concrete in these regions
eventually crushed. Also, during test, it was found that the steel of the wall in the crushed regions
buckled and separated from the connected steel cover plate in the last loop of test. In contrast,
referring to Figure 4b1, it is found that there are observable diagonal cracks in the wall of specimen
PMLL1b. The shear force sounds has transferred to this precast wall and its performance is well
developed. The properties and steel ratio of specimen PMLL1b are the same as specimen PMLL1a,
except the connected steel cover plate is different. Referring to Table 2, the ultimate load and
displacement of specimen PMLL1b are higher than specimen PMLL1a. However, the energy
dissipation and ductility of specimen PMLL1b are lower than specimen PMLL1a. Similar results are
found for specimens PMLL3a and PMLL3b. Referring to Figures 5g1 and 5h1, it is found that there
are much more observable diagonal cracks in the wall of specimen PMLL3b. Due to more steel
around the open region of connected steel cover plate for specimen PMLL3a, the local cracks are not
occurred in the bottom corners of the wall. Referring to Table 2, the ultimate load, ultimate
displacement, energy dissipation, and ductility of specimen PMLL3b are higher than specimen
PMLL3a. The connected steel cover plates with two channel plates is demonstrated to produce better
performance than rectangular steel cover plate with an opening.



3. Effect of orientation of wall reinforcements
The behavior of precast specimens is significantly affected by orientation of wall reinforcements.
Referring to Figures 5a1 and 5g1, the crack patterns of specimens PMLL1a and PMLL3a are
obviously different. There is no observable diagonal crack in the wall and the concrete crushed at the
bottom corners of wall for specimen PMLL1a. In contrast, there are observable diagonal cracks in the
wall and there is no concrete crush in the bottom corners of wall for specimen PMLL3a. However, the
experimental results in Table 2 show that there is no large deviation on ultimate load, ultimate
displacement, energy dissipation and ductility for both specimens PMLL1a and PMLL3a.
Referring to Figures 5b1, 5e1, and 5h1, the behavior of specimens PMLL1b, PMLL2b, and PMLL3b
are also different. The concrete of the left bottom corner of wall crushed for both specimens PMLL1b
and PMLL2b. The steel of specimens PMLL1b buckled during test. In contrast, there is no concrete
crush for specimen PMLL3b. Referring to Table 2, one can see that the energy dissipation, ultimate
displacement, and ultimate load of specimens with modified conventional reinforcement are higher
than the comparable specimen. Similar results are also found for specimens PMHL1b, PMHL2b, and
PMHL3b. The modified conventional reinforcement with more steel at the corners is demonstrated to
produce better performance than the other orientations.




4. Effect of steel ratio and strength of concrete
The crack pattern and crack growth of specimens with various concrete strength and steel ratio are
similar, while their performance is obviously affected by the material properties. Referring to Table 2,
the ultimate load, ultimate displacement and energy dissipation of specimens with higher concrete
strength (specimens PMHL1b, PMHL2b, and PMHL3b) are larger than the comparable specimens
with lower concrete strength (specimens PMLL1b, PMLL2b, and PMLL3b). Similar results are also
found for the effect of steel ratio. Referring to Table 2, the ultimate load, ultimate displacement,
energy dissipation, and ductility of specimen PMLH1b are higher than specimen PMLL1b. The larger
steel ratio and stronger concrete are demonstrated to increase the earthquake resistance of structures.


[تصویر:  gfbtuaz5ftqycoic5oa6.jpg]

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[تصویر:  1kylou502hpp4kxzz6uh.jpg]

CONCLUSIONS


The seismic behavior of precast reinforced concrete walls is studied by large scale test. The
parameters of connected steel cover plate, orientation of wall reinforcements, steel ratio of wall, and
strength of concrete were studied. The major findings are summarized as follows:
1. The precast reinforced concrete wall can effectively increase the earthquake resistance of structures.
Although the ultimate load of specimens with precast reinforced concrete walls is lower than that
of cast-in-place specimens. However, the ultimate displacement and energy dissipation of
retrofitted specimens by using precast reinforced concrete walls are higher than those of cast-inplace
specimen.
2. The performance of a precast reinforced concrete wall is affected by connected steel cover plate.
The precast reinforced concrete wall can fully develop its performance by using connected steel
cover plates with two channel plates which were fixed by M16 chemical anchors.
3. The modified conventional reinforcement with more steel at the corners produces better
performance than the other orientations. The energy dissipation, ultimate displacement, and
ultimate load of specimen with modified conventional reinforcement are higher than the
comparable specimen.
4. The larger steel ratio and stronger concrete also definitely increase the earthquake resistance of
structures. The energy dissipation, ultimate displacement, and ultimate load of these specimens
become higher.



1 Professor, Department of Civil Engineering, Sustainable Environment Research Center, National Cheng Kung
University, Tainan, Taiwan. Division head of National Center for Research on Earthquake Engineering, Taipei, Taiwan. email:
ceyjc@mail.ncku.edu.tw
2 Professor, Department of Industrial Safety and Hygiene, Chia-Nan University of Pharmacy and Science, Tainan, Taiwan.
3 Instructor, Department of Civil Engineering, National Cheng Kung University, Tainan, Taiwan.
4Associate research fellow, National Center for Research on Earthquake Engineering, Taipei, Taiwan.





REFERENCES

Chiou, Y. J., Hsiao, F. P., Liou, Y. W. and Huang, C. C., (2006), “Structural Behavior of Reinforced
Concrete Framed Walls under Horizontal and Vertical Loads” Submitted to Journal of Structural
Engineering, ASCE.
Crisafulli, F., Restrepo, J., and Park, R., (2002), “Seismic Design of Lightly Reinforced Precast
Concrete Rectangular Wall Panels,” PCI Journal, 47 (4): 102-118.
Greifenhagen, C., and P. Lestuzzi, (2005), “Static cyclic tests on lightly reinforced concrete shear
walls, ” Journal of Engineering Structures, 27 (11): 54-65.
Hidalgo, P. A., C. A. Ledezma, and R. M. Jordan, (2002), “Seismic behavior of squat reinforced
concrete shear walls,” Earthquake Spectra, 18 (2): 287-308.
Kurama, Y., Pessiki, S., Sause, R., and Lu, L. W., (1999), “Seismic Behavior and Design Unbonded
Post-Tensioned Precast Concrete Walls,” PCI Journal, 44 (3): 72-89.
Kurama, Y., Sause, R., Pessiki, S., and Lu, L. W., (1999), “Lateral Load Behavior and Seismic Design
Unbonded Post-Tensioned Precast Concrete Walls,” ACI Structural Journal, 96 (4): 622-632.
Palermo, D. and F. J. Vecchio, (2002), “Behavior of three-dimensional reinforced concrete shear
walls,” ACI Structural Journal, 99 (1): 81-89.
Sittipunt, C., S. L. Wood, P. Lukkunaprasit, and P. Pattararattanakul, (2001), "Cyclic Behavior of
Reinforced Concrete Structural Walls with Diagonal Web Reinforcement," ACI Structural Journal,
98 (4): 554-562.
Zhang, Y. and Z. Wang, (2000), “Seismic behavior of reinforced concrete shear walls subjected to
high axial loading,” ACI Structural Journal, 97 (5): 739-750. 
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