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International Journal of Civil & Environmental Engineering IJCEE-IJENS Vol:10 No:04 47

101704-9292-IJCEE-IJENS © August 2010 IJENS I J E N S

“Structural Behaviour of Steel Fabric Reinforced

Concrete Wall Panel Under Eccentric Loading”

Ir Ruzitah Supinyeh1, Ir Dr Siti Hawa Hamzah

2

1M.Sc Civil Engr Student, Faculty of Civil Engineering, Universiti Teknologi MARA, 40450, Shah Alam, Malaysia.

([email protected]) 2 Professor, Faculty of Civil Engineering, Universiti Teknologi MARA, 40450 Shah Alam, Malaysia ([email protected])

Abstract-- Recently reinforced concrete walls have gained

greater acceptance from many countries in conjunction with the

Industrialized Building System (IBS). Essentially, the system gives an advantage in reducing the dependency of foreign labour

and a better investment in technologies, techniques and processes

of construction.

Steel fabric reinforced concrete wall panel has been used in

Malaysia in the past few years and can still be considered as a new construction method. This type of wall may require

sequential analysis in making an effective product that gives

advantages in all aspects and gives better performance. This

research involved laboratory experimental work and model by

using a finite element computer program as comparison of the results.

Laboratory works tested eight wall samples with size of 1.0m x

1.5m and 0.75m thick. (Length:Height:Width). The wall samples

reinforced with double layer steel fabric size B7 and concrete

Grade 30. The wall panel tested under axial load with the eccentric t/6 or 12.5mm of wall thickness. Variations of support

condition include of t/6 with pinned or fixed imposed at the top

and bottom of the wall panel.

Experimental result shows due to eccentric loading that all of the

wall panels failed in compression shear which the wall panels shown a single curvature pattern where it bends towards the rear

side. There are no cracks seen on both front and rear surfaces of

the wall panel unless it crushed at top and base of the wall. It is

observed that the ultimate eccentric loads (Pult) of 991.45 kN and

maximum deflection 9.67mm obtained from the experimental works.

The computer analysis shows that the wall panel failed by

compression. Higher stress concentration appears at the upper

and bottom corner of the wall panel. The deflection obtained

over by 18.3% compared with the experimental results. Comparison with the experimental and the computer analysis

results were found in good agreement.

Index Term-- concrete wall panel, steel fabric, eccentric

1.0 INTRODUCTION

A changed in structural design from moment-resisting to

flexible frames with stiff shear resisting elements has occurred

in recent years. In Malaysia the changed starts in late 1990's

when the Government Plan For Zero squatters in Kuala

Lumpur. As such steel tunnel formwork system or Tunnel

form had been used in replacement of conventional sawn

timber formwork. They are a number of generic forms of

shear wall structure or Industrial Building System (IBS)

named as Steel Tunnel Formwork System, Steel Shear Wall

Climbing Formwork System and Steel Wall Panel System

[1].

Shear wall offers efficient means of enclosing and utilizing

space. Thinner walls reduce the cost of buildings as well as

increase the net lettable space of a building. Shear wall did

not require column and beam as structural members. It can act

as column and could transfer load from roof to foundation. A

combination of pile and raft foundation is practically and

economical design when the shear wall floor started at ground

floor.

Shear wall building is commonly built to consist 10 to 35

storey. This is the most suitable construction method to build

apartment units in several blocks and within limited time

frame. The construction speed of the shear wall is normally

controlled by the concreting and subsequent depropping of the

floor slabs. Props should be left in place until the slab has

achieved adequate strength to resist further propping and

construction loads.

Practically the thickness of wall is varies from 100mm to

225mm. Loads on wall are usually in plane axial loads and

lateral load but often they could become accidental eccentric

loads due to constructional imperfections also non uniform

distribution of load on wall panel. As the thickness of the wall

panel is small and the wall is a slender element thus the

analysis of wall panel shall include the considerations of the

stability.

Steel fabric is widely used in reinforce shear wall. In the

specification for steel welded fabric for the reinforcement of

concrete according to Malaysia Standard MS 145:2001

(Second Edition), the steel strength is of grade 510 steel [2].

The substitution of normal rebar to steel fabric expedites faster

installation and considerable costs saving.

1.1 EXPERIMENTAL PROGRAM

The experimental work involved testing of eight (8) wall

panels with the specified material properties. The material

used has been confirmed earlier by conducting cube and steel

fabric strength tests. The structural performance of the wall

panel such as the ultimate strength load, mode of failure and

cracking pattern will be determined. Eight wall panels

reinforced with double layer of steel fabric type B385 (B7)

with a dimension of 75 mm thick (width) x 1000 mm long x

1500 mm high were prepared. For steel fabric type B7 the

main and cross wire are 100mm and 200mm centre to centre

spacing. The aspect ratio (h/L) is 1.5 and the slenderness ratio



(h/t) is 20. The specification and dimension of the wall panel

is shown in Figure 1.1 The wall panels were constructed using

concrete Grade 30 Normal Ordinary Portland Cement (OPC)

with a water cement ratio of 0.58. These wall panels were

tested under compressive axial load with 12.5mm

eccentricity. Testing were carried out with two main support

variations; pinned ends (PPe) and pinned-fixed ends (PFe)

also the variations of eccentric for top and bottom support

conditions.

Fig. 1.1. Wall Panel and steel fabric reinforcement detail

According to BS 8110: Part 1: 1997 Clause 3.9.3.3

the eccentricity should be taken as not less than h/20

or 20 mm if less where h is the thickness of the wall

[3]. In this research the eccentricity of tw/6 (12.5

mm) is used according to American Concrete

Institute (ACI 318) [4]. Determination of structural

behaviour includes mode of failure either buckling or

crushing, deflected shape (curvature), stress -strain

and load-displacement relationship. From the

experimental work, graph of stress versus strain and

load versus displacement are plotted and mode of

failure, deflection profile and crack pattern would

determine and will shown accordingly.

This research is expected to provide clear

understanding and knowledge of the structural

behavior and carrying strength capacity of such

system to both researchers, designers and contractors .

2.0 THEORETICAL ANALYSIS OF WALL PANEL

The maximum stress in the wall can be occurred when both

the axial load and the moment are applied. Since the radius of

gyration is defined as:

AIr /

(2-1)

where;

I = moment of inertia and

A = cross section area of wall

The maximum stress can be written in a form called the secant

formula as,

EA

P

r

L

r

ec

A

P

2sec

21max

(2-2)

where;

σ max = Maximum elastic stress

e = Eccentricity of the load P

c = Distance from neutral axis to the outer fiber

A = Cross-sectional area

E = Modulus of elasticity

r = Radius of gyration

I = Moment of inertia

h = Height of wall

L = Length of wall

2.1.1 Design wall Panel using British Standard (BS

8110: 97 Part 1)

In British Concrete Standard (BS8110-97), there’s a section

that deals with the design of plain concrete walls (Section

3.9.4) [3]. This section recommends that the design ultimate

axial force in a plain concrete wall may be calculated on the

assumption that the members transmitting forces on the walls

are simply supported.



2.1.2 Determination of Design Ultimate Axial Force

Using Simplified Method

For the determination of design ultimate axial load per unit

length, the equations prescribed for different types of concrete

walls as follows:

cuww fe2t3.0n

… (2-3)

Where nw is the ultimate axial load per unit length of a wall in

compression and fcu is the characteristic compressive cube

strength for concrete in Mpa.

For slender braced plain concrete walls:

cuaxw feehn )22.1(3.0

… (2.4)

where:

ex is the resultant eccentricity of load at right angles to

the plane of the wall (with minimum value h/20).

ea is the additional eccentricity due to deflections which may be taken as le

2/2500h where le is the effective height of

the wall. or unbraced plain walls:

cu1,xww fe2t3.0n

… (2.5)

and cu2,xww fe2t3.0n

… (2.6)

Where ex,1 and ex,2 are the resultant eccentricity calculated at

the top and bottom of the wall respectively.

2.1.3 Effective Height

The effective height of unbraced plain concrete walls is given

as follows:

a. wall supporting at its top a roof or floor slab

spanning at right angles ; le =1.5lo;

b. other walls le=2 lo

lo, may be measured mid-way between eaves

and ridge

The effective heights of braced plain concrete walls

are:

a) where an lateral support resist both rotational

and lateral movements at both ends and le =

0.75L; and for any lateral support resists both

rotational and lateral movements at one end and

the other is free is le = 2.0L.

b) for any lateral support resist only lateral

movements at both ends, le = Lo; and for any

lateral support resists only lateral movement at

one end and the other end is free is le = 2.5Lo.

L is the horizontal distance between centres of lateral

restraints and Lo is clear height of wall between

lateral supports.

2.1.4 Alternative to Design Equation

British Standard outlines an alternative procedure for the

design of reinforced concrete walls in Section 3. The code

calculates the failure load using the following formula;

yscccuw fA67.0Af35.0n

… (2.7)

If the wall is not subjected to a significant moment, due to the

nature of the structure and the arrangement of the structural

elements, the above equation is increased to:

yscccuw fAAfn 75.04.0

… (2.8)

where;

cuf = characteristic strength of concrete

cA = gross area of concrete at a cross section

scA = area of compression reinforcement, per unit

length of wall

yf = characteristic strength of compression

reinforcement

For this alternative design method to be valid, the

slenderness ratio of the wall must satisfy:

a) for braced walls:

le /h ≤ 40, or le /h ≤ 45 if vertical reinforcement

exceeds 1%

b) for unbraced walls:

le /h ≤ 40

The slenderness effects can be ignored for short walls.

Reinforcement are defined as short if the height-to-thickness

ratios are:

a) le /h ≤ 15 for braced walls

b) le /h ≤ 10 for unbraced walls

However, nw is the total design axial load on the wall due to

design ultimate loads. The walls are designed for a uniformly

distributed imposed load and the span on either side of the

wall does not differ by more than 15%.

2.1 GAP OF RESEARCH

The review of literature of the previous researcher gave better

understanding about wall panel behaviour and proposed

parameter in the study area to be confirmed or revised. The

mode of failure for the wall panel were depends on types of

material used, structure behaviour and application of loadings.

It is important to understanding the behaviour of wall panel

reinforced with steel fabric wire mesh with eccentric loading.

The use of steel fabric wire mesh in the wall construction

required attention due to misconceptions or cost factor. The

strength of wall panel depends on the percentage of steel in

concrete and concrete grade used. This study is sought to

investigate the performance of wall using double layer of steel

fabric as normal practice in Malaysia.



3.0 SPECIFICATION OF WALL PANEL

The experimental work is conducted based on structural

behaviour of steel fabric reinforced concrete wall panel under

eccentric loading. The loads will be applied at t/6 from the

centre of wall panel. A total number of eight (8) samples of

steel fabric reinforced concrete wall panel were prepared. The

specified characteristic strength of the concrete wall panels is

30 N/mm2 with identical dimension of 75mm thick, 1000mm

length and 1500mm height. The aspect ratio (h/L) and

slenderness ratio (h/w) of the wall panel are 1.5 and 20

respectively, whereas it is classified as normal wall. This wall

panel was subjected to an axial load with an eccentricity of

tw/6 on both top and bottom. The eccentricity specified as by

code (BS8110 Part 1:, 1997) is not to be less than t/6 or 20mm

[3]. The eccentricity for this experiment is 12.5mm from the

cross section of the centroidal axis. The wall sample design

and used properties as stated in BS 8110 Clause 3.9.3.

T ABLE 3.1 SAMPLES SPECIFICATION

Samples No

Set Up No

Eccentricity

Condition

PPe 1 Set up 1 et = t/6

PPe 2 Set up 2 eb=et = t/6

FPe 1&2 Set up 3 et= eb =t/6

PFe 1&2 Set up 4 eb= et =t/6

PP-e Set up 5 eb=-et =t/6

PF-e Set up 6 eb=-et = t/6

Table 3.1 shows the specification of eight wall samples which

tested at different end-condition at both end. Samples PPe1

and PPe with end condition pinned on top and bottom. Sample

FPe with end condition fixed on top and pinned at the bottom

while samples PFe is a reverse of FPe. Samples PP-e with end

condition pinned top and bottom but the eccentric load is on

top reversed position than at the bottom. Sample PF-e with

end condition pinned on top and fixed at bottom and then the

eccentric load was imposed at reverse position at the bottom.

Figure 3.2 shows six different types of experimental set-up

and end condition. Set-up 1 shows the axial load on top with

eccentric of 12.5mm from the centre of wall. Set-up 2, 3 and

4 show the axial load on top and bottom with eccentric of

12.mm imposed at the same site position top and bottom. Set

up 5 and 6 shows the axial load on top with eccentric 12.5mm

and at the bottom the eccentric is at the reverse side.



Fig. 3.2. Support set up condition



3.1 CONSTRUCTION OF WALL PANEL

A total of eight (8) samples wire fabric reinforced concrete

wall panel of formwork or mould were prepared. The

formwork is designed and built accurately to the desired

shape, size, verticality and horizontally. Plywood with

thickness 10mm and timber 75mm x 50mm were used as

formwork. The formwork prepared in horizontal form due to

the difficulty in compact the concrete during casting of

concrete. The work was fabricated at Fabrication Laboratory

of the Civil Engineering Faculty [4].

A total eight numbers of concrete wall panels reinforced with

double layer of wire mesh type B 385 (B7) with a dimension

of 75x1000x1500mm (Width: Length: Height) were cast at

Concrete Laboratory of Civil Engineering Faculty [4,5]. The

concrete wall panels were constructed using specified material

properties that have been confirmed earlier by conducting

cube and fabric test.

3.2 EXPERIMENTAL SET UP

Reaction frame together with double hydraulic actuator were

used to test wall panel under eccentricity loading. The wall

was anchored to a strong floor and two samples have been

tested in vertical position. Figure 3.4 shows the reaction frame

together with load cell and double actuator which will

imposed vertical loading to wall panel. Figure 3.5 shows the

experimental set-up of wall panel clamped to reaction frame.

Fig. 3.4. Reaction frame used to test wall panel

Fig. 3.5. Experimental Set -up

The concrete wall panel was placed on the center of reaction

frame accurately. The wall has been painted in white color to

ensure the crack pattern could be observed easily. It was

supported by one hydraulic jack with a 2000 kN capacity. The

jacks was transmitted a vertical axial load at the top of the

wall in order to achieve the pinned support at both ends (top

and bottom) of this wall. The boundary condition was set up

using circular rod. The circular rod and the steel plate acted in

transferring the load to the wall panel. Its have been located

with eccentricity of tw/6 on both top and bottom of wall panel.

In this experiment, strain gauges placed at steel fabric to

measure the strain of the wall panels under axial load. The

strain gauges were placed at proper location and mounted on

cleaned and smooth surface of the wall panel. For each wall

panel, four strain gauges were used two at the front

longitudinal bar and two at the rear longitudinal bar as shown

in Figure 3.6. When using strain gauge, it is very important to

make sure that the bond between the gauge and the

reinforcement is tight glue and sealed with electric tape.

Beside strain gauge, linear variable differential transformer

(LVDT) also were used to measure small movements or

deformations of the wall panel. The schematic arrangement of

the LVDT is shown in the Figure 3.7. The instruments were

calibrated and adjusted properly, before applying the load.

Then the load was applied gradually increased until the wall

fail and no more load can be applied. All dimension of width

and lengths crack of crack were measured and necessary data

were recorded automatically by Data Logger which connected

to the computer. The crack pattern was also marked with

marker for at each load stage. Cracks were marked on the

surface of the sample indicating the corresponding load. At



each load increment, deflection has been recorded. Figure 3.8

shows the detail location of wall panel, load cell. LVDT and

end condition of the supports. Load cell was attached to

2000kN hydraulic jack for incremental of applied load.

Fig. 3.6. Arrangement of strain gauge on reinforcement of steel fabric

T5

T4

T3

T2

T1

Fig. 3.7. Arrangement of LVDT



Fig. 3.8. Detail test set-up in the laboratory

3.3 TESTING PROCEDURE

The experiment work was to complied with all the

specification of material used as stated in the current code of

practice. The testing procedure and set up for the material and

were also loading followed the procedure used in actual

works. The main test set up for the panel testing were the

actual experiment with limitation of the reaction frame. The

lever arm attach to the machine were not contacted directly to

the wall panel. It was acted as a support to prevent the panel

from sway and prevent damage the LVDT. The panel were

casted in horizontal position because it is difficult to prepare

the formwork vertically and compacting of concrete will be

very easy. An incremental of applied load of 10% to wall

panel under vertical loading could easily measure the crack

pattern and lateral displacement. Five LVDT were measured

lateral displacement at different height of wall.

4.0 EXPERIMENTAL RESULTS

The structural behaviour of the panels was observed during

experimental work by measuring the lateral deflections at the

location of LVDT and deformation of strain gauges at the

reinforcement bars. In order to have better understanding the

performance of each panel, the test results were analyzed in

the context of eccentric load bearing capacity, profile -

displacement, load - displacement profile, stress – strain,

cracking pattern and mode of failure.

According to American Concrete Institute (ACI 318), the

ultimate load obtained from the formula for pinned top and

bottom is 528.41 kN. The ACI formula for pinned on top and

fixed on the bottom or otherwise is 649.69 kN. Meanwhile,

British Standard BS 8110: Part 1: 1997 in Clause 3.9.4.16, the

design ultimate load, nw is 324.0 kN for pinned on top and

bottom of wall. For the pinned on top and fixed on bottom or

otherwise the design ultimate load, nw is 355.05 kN. From

these values, it was found out that the ultimate load for PPe1

and PPe2 recorded from experiment is lower than the

proposed equation likes in ACI 318 and BS8110 27.28% and

196.59%, respectively. The FPe samples accounted less

between 27.28% and above 30.44%, from the theoretical

values. Sample PFe1 experienced the higher value between

33.07% and 63.42% but sample PFe2 has lower up to

196.59%. Similarity results obtained for sample PP-e and

PPe2 in the range of lower 192.37% and upper 67.32%. Also

for sample PF-e shown similarity with sample PFe2 of lower

196.59% and upper 1.75%.

According to BS 8110: Part 1: 1997 Clause 3.9.4.16 the value

of nw 324.0 and 355.05 kN is the maximum design ultimate

axial load for slender braced plain wall, where reinforcement

is neglected. An alternative design method is to use Clause

3.8.4.3 value nw 1047.26 kN with limitation of wall assume as

column design and without significant moments. In America

Standard ACI 318 the empirical design formula allowed for a

minimum reinforcement contents. Steel reinforcement

improved the strength of the wall 30% higher ultimate load

than theoretical value.

Table 4.1 compared the experimental and theoretical results of

ultimate load with eccentricity of tw/6. The experimental

results have lower value than the theoretical values. It is

meaning to say that the codes either ACI or BS 8110 have a

upper limit band than the experimental value. Therefore, the

strength capacity of shear wall with double layer has lower

value than as specified in both standards. Further

investigation and improvement should be made to improve



their strength so that the actual ultimate value must higher

than the codes.

Figure 4.1 shows ultimate load for each samples from the

experimental, theoretical and maximum deflection. Maximum

deflection measured from the experiment have lower value

than the theoretical.

T ABLE 4.1

EXPERIMENTAL AND THEORETICAL RESULTS

SAMPLE EXPERIMENTAL

ULTIMATE LOAD

(kN)

BASIC REQUIRED BY CODE OF

PRACTICE BS8110 & ACI

(kN)

PERCENTAGE

%

PPe 1 382.12 ACI 318 = 528.41

BS 8110 Cl. 3.9.4.16 = 324.00

BS 8110 Cl. 3.8.4.3 = 1047.26

-38.28

15.20

-174.07

PPe 2 358.20 ACI 318 = 528.41

BS 8110 Cl. 3.9.4.16 = 324.00

BS 8110 Cl. 3.8.4.3 = 1047.26

-47.52

9.55

-192.37

FPe 1 362.03 ACI 318 = 649.69

BS 8110 Cl. 3.9.4.16 = 355.05

BS 8110 Cl. 3.8.4.3 = 1047.26

-79.46

1.93

-189.27

FPe 2 510.46 ACI 318 = 649.69

BS 8110 Cl. 3.9.4.16 = 355.05

BS 8110 Cl. 3.8.4.3 = 1047.26

-27.28

30.44

-105.16

PFe 1 970.70 ACI 318 = 649.69

BS 8110 Cl. 3.9.4.16 = 355.05

BS 8110 Cl. 3.8.4.3 = 1047.26

33.07

63.42

-7.89

PFe 2 353.10 ACI 318 = 649.69

BS 8110 Cl. 3.9.4.16 = 355.05

BS 8110 Cl. 3.8.4.3 = 1047.26

-84.00

-0.55

-196.59

PP-e 991.45 ACI 318 = 528.41

BS 8110 Cl. 3.9.4.16 = 324.00

BS 8110 Cl. 3.8.4.3 = 1047.26

46.79

67.32

-5.63

PF-e 361.36 ACI 318 = 649.7

BS 8110 Cl. 3.9.4.16 = 355.05

BS 8110 Cl. 3.8.4.3 = 1047.26

-79.79

1.746

-189.81



ULTIMATE LOAD VS DISPLACEMENT

0

100

200

300

400

500

600

700

800

900

1000

1100

0 1 2 3 4 5 6 7 8 9 10 11 12 13

Displacement (mm)

Load

(kN

)

BS8110-1PP

BS8110 -1PF

BS8110-2

PFe1

PFe2

PPe1

PPe2

FPe1

FPe2

PP-e

PF-e

Note: BS8110-1 is BS 8110 Cl. 3.9.4.16 = 324.0kN for pinned-pinned

BS8110-1 is BS 8110 Cl. 3.9.4.16 = 355.05kN for pinned-fixed

BS8110 -2 is BS 8110 Cl. 3.8.4.3 = 1047.26kN Fig. 4.1. Experimental and Theoretical

4.1 DEFLECTION PROFILE

The measurement of deflection was taken at every 10 kN load

increment. The relationships between transducers reading

with respect to the applied load were plotted as shown in

Figure 4.2. The maximum lateral displacement for PPe

samples is located at mid height of wall samples, i.e. 750 mm

from the base end. Meanwhile, for PFe samples it occurred at

1050 mm (0.7L) from the base of wall panel. Detailed

readings recorded in all samples are shown in Table 4.2.

T ABLE 4.2 DEFLECTION PROFILE SUMMARY

Note : Highlighted value is the highest magnitude of displacement

Sample PPe1 PPe2 FPe1 FPe2 PFe1 PFe2 PP-e PF-e

Load 382.12kN 358.2kN 362.03kN 510.46kN 970.70kN 353.10kN 991.45kN 361.36kN

P P P P P P P P P P P P P P P P

initial ultimate initial ultimate initial ultimate initial ultimate initial ultimate initial ultimate initial ultimate initial ultimate

Dis

pla

ce

me

nt

T1 0.04 0.57 0.04 1.14 0.07 0.26 0.04 1.75 0.37 0.63 0.04 3.09 0.00 2.12 0.78 0.56

T2 0.29 2.25 0.63 2.35 0.07 0.72 0.07 2.31 0.22 9.67 0.65 2.83 0.11 6.50 0.58 0.33

T3 0.35 2.45 0.75 2.75 0.07 2.02 0.11 3.27 0.22 9.21 0.11 1.77 0.07 5.21 0.33 0.33

T4 0.37 1.47 0.30 1.78 0.04 2.99 0.19 5.39 0.07 7.76 1.35 3.05 0.04 5.39 0.19 0.15

T5 0.11 0.93 0.05 1.23 0.04 1.74 0.04 4.99 0.07 4.86 0.04 1.58 0.22 2.17 0.18 0.98



All samples showed a single curvature prevailing buckling

behaviour with maximum deflection dominated at positions

agreeing with the support conditions as mentioned in Euler

buckling theory. The deflection profile and failure pattern for

both PPe and PFe is agreeable and supported by Wang et. al.

(1997) who indicated that wall tested under action of eccentric

load top and bottom of wall deflected with single curvature

[6]. Figure 4.4 has shows the deflection profile of wall panel

at different height and end conditions of support.

WALL PROFILE VS DEFLECTION for ALL SAMPLES

EXPERIMENT

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

1500

0 1 2 3 4 5 6 7 8 9 10 11

Displacement (mm)

He

igh

t (m

m)

PPe1

PPe2

FPe1

FPe2

PFe1

PFe2

PP-e

PF-e

Fig. 4.2. Deflection profile

4.2 CRACK PATTERNS

PPe and PFe sampleswere not crack on the surfaces of the

wall panels based on visual observations absent. However,

the wall panel crushed at the upper and lower ends of the

samples (see Figure 4.3 to 4.5) after yielding of the

reinforcement had occured. The crushed sections at the base

showed complete load distribution took place within the

concrete matrix. Even though all samples were designed with

capping of the steel fabric layers at both upper and lower ends,

the crushed ends showed compression failure of the concrete

initiated the failure of the wall panels. The details for crack

pattern for all walls are shown in Table 4.3 Based on the

visual observation most of spalling of concrete and cracks

were occur at bottom and top of wall panel.

T ABLE 4.3 DESCRIPTION OF AND LOCATION OF CRACKS AT 8 SAMPLES

SAMPLE CRACK LOCATION SIDE CRACK SURFACE

CRACK

PPe1 Crush at top and base of

the wall None None

PPe2 Crush at top and base of

the wall

Crush on left edge at the

base of the wall None

FPe1 Crush at bottom of the

wall None None

FPe2 Crush at bottom of the

wall None None

PFe1 Crush at top of the wall Crush at left and right

edges of the wall None

PFe2 Crush at top of the wall Crush at left and right

edges of the wall None

PP-e Crush at top and base of

the wall None None

PF-e Crush at top and base of

the wall None None



Fig. 4.3. PPe1 crushing at both end

(a) (b) (c)

Fig. 4.4. PFe1 crushing at both ends

Fig. 4.5 (a) : PFe2 crushing at base end

4.3 STRESS STRAIN RELATIONS HIP

Figure 4.6 shows stress-strain relationships for wall panel

samples PFe1, PPe1 and FPe1. In the Table 4.4 shows strain

gauge reading on the steel fabric and the stress calculation

using secant formula. All strain in the longitudinal bars

increased linearly with respect to the applied load onto the

wall.

Stress vs Strain for PFe1

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

20000

22000

24000

26000

0 200 400 600 800 1000

Strain (um/m)

Str

es

s (

kN

/m2)

F1

R1

F2

R2

Stress vs Strain for PPe1

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

11000

0 50 100 150 200 250 300 350 400

Strain (um/m)

Str

es

s (

kN

/m2)

F1

F2

R2

R1

Stress vs Strain for FPe1

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

0 50 100 150 200 250 300 350 400

Strain (um/m)

Str

es

s (

kN

/m2)

F1

F2

R1

R2

Fig. 4.8. Stress and strain relationship

T ABLE 4.4 MEASUREMENT ON STEEL FABRIC

Sample Maximum

Stress (kN/m

2)

Strain Longitudinal

wire (µm)

Remark

PPe1 10 189.87

L F 1050 = 0.261

L R 1050 = 0.372

L F 750 = 0.368

LR 750 = 0.313

Maximum stress at middle of

wall height

PPe2 9 553.07

L F 1050 =0.290 L R 1050 =0.273

L F 750 = 0.288

LR 750 = DAMAGE

Maximum stress at middle of

wall height

FPe1 9 654.13 L F 1050 =

0.344 L R 1050 =

Maximum stress at



0.242 L F 750 =

0.279 LR 750 =

0.201

three quarter of

wall height

FPe2 13 612.27

L F 1050 = 0.084

L R 1050 = 0.103

L F 750 = 0.130

L R 750 = 0.212

Maximum stress at

three quarter

bottom of wall

height

PFe1 24 343.73

L F 1050 = 1.240

L R 1050 = 1.280

L F 750 = 0.99

L R 750 = 1.00

Maximum stress at

three quarter of

wall height

PFe2 9 416.00

L F 1050 = 0.074

L R 1050 = 0.177

L F 750 = 0.013

LR 750 = 0.056

Maximum stress at

three quarter of

wall height

PP-e 26 438.67

L F 1050 = 0.891

L R 1050 = 0.054

L F 750 = 0.699

LR 750 = 0.924

Maximum stress at

three quarter bottom

and top of wall

height

PF-e 9 636.27

L F 1050 = 0.145

L R 1050 = 0.034

L F 750 = 0.116

LR 750 = 0.239

Maximum stress at

three quarter

bottom of wall

height

Samples PPe1 and PPe2 experienced strain of the range

between 0.261 to 0.372, whereby the PFe samples experienced

in the range of 0.013 to 1.280. Both types of samples shows

similarity in which the PPe samples have and average of 5 %

different between the front to the rear surface at height of 750

mm and 1050 mm respectively. The maximum stress for

PPe1 and PPe2 are 10,189.87 kN/m2

and 9,553.07 kN/m2

respectively. Samples FPe1 and FPe2 show different stress

behaviour at the top and bottom in the range of 0.344 and

0.212 respectively with the average 38% different. Sample PP-

e experienced maximum stress at rear face on the bottom and

front face on top due to symmetrical eccentricity. The

maximum stress for sample PP-e is 26,438.67 kN/m2

and the

support condition is stable. The same experienced to be

shown by sample PF-e but the support condition not stable

compare with sample PP-e the maximum stress is 9 636.27

kN/m2 about the average of the sample PF-e, PPe2, FPe1 and

PFe2 is 9564.86 kN/m2.

From theoretical analysis the maximum stress value

is 14, 437 kN/m2. It is about 33% and 83% difference

between average and the higher. Graph of stress

versus strain of steel fabric at different location

shown for all samples in the Appendix F.

4.4 NUMERICAL ANALYSIS RESULTS

4.4.1 Height versus displacement

The numerical analysis using PROKON software were model

for sample with the support condition top pinned and bottom

fixed (PFe) subject to eccentricity loading of t/6 [7]. The

model was run with 3D linear analysis. The maximum

displacement is measured at the centre of wall or middle node

as per experiment where the location of LVDT location. The

maximum displacement of 11.72mm for load case DL18 or

1000kN were satisfied the code of practice (BS 8110 part 1

1997: Clause 3.9.3.8.2). The maximum displacement sample

PFe1 is 14% different.

The summary of maximum displacement is shown in Table

4.5 and Figure 4.9 shows the wall profile versus displacement

indicated the maximum displacement occurred at 0.7 height of

wall. Figure 4.10 show the displacement for load case DL10.



T ABLE 4.5 DISPLACEMENT SUMMARY

Wall LOAD CASE DL1 DL5 DL10 DL12 DL14 DL15 DL17 DL18 DL19

Height LOAD kN 10 50 100 300 500 600 800 900 1000

(mm) Node no. Displacement (mm)

0 10 0 0 0 0 0 0 0 0 0

100 21 0 0.02 0.04 0.11 0.18 0.21 0.28 0.32 0.35

200 32 0.01 0.06 0.13 0.39 0.64 0.77 1.03 1.16 1.26

300 43 0.03 0.13 0.26 0.79 1.32 1.59 2.12 2.38 2.59

400 54 0.04 0.21 0.43 1.29 2.15 2.57 3.43 3.86 4.2

500 65 0.06 0.3 0.61 1.82 3.04 3.64 4.8 5.46 5.95

600 76 0.08 0.39 0.78 2.35 3.92 4.71 6.27 7.06 7.69

700 87 0.09 0.47 0.95 2.84 4.73 5.68 7.57 8.52 9.27

800 98 0.11 0.54 1.08 3.24 5.39 6.47 8.63 9.74 10.57

900 109 0.12 0.58 1.17 3.5 5.8 7 9.33 10.5 11.43

1000 120 0.12 0.6 1.2 3.59 6 7.18 9.57 10.77 11.72

1100 131 0.1 0.58 1.15 3.46 5.79 6.92 9.23 10.32 11.31

1200 142 0.08 0.515 1.03 3.08 5.15 6.15 8.26 9.23 10.05

1300 153 0.05 0.4 0.8 2.39 4 4.78 6.38 7.21 7.81

1400 164 0 0.23 0.46 1.38 2.31 2.75 3.67 4.15 4.5

1500 175 0 0 0 0 0 0 0 0 0

Wall Profile vs Displacement for

NUMERICAL ANALYSIS

PFe

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

1500

0 1 2 3 4 5 6 7 8 9 10 11 12 13

Displacement (mm)

Heig

ht

(mm

) DL1

DL5

DL10

DL12

DL14

DL15

DL17

DL19

DL18

DL19

Max

Max deflection

at 0.7 w all

height or at

1050 mm

Fig. 4.9. Plot graph load versus displacement using PROKON load case DL1

to DL19

Fig. 4.10. Displacement profile for load case DL10

4.4.2 Stress Versus Load

The stress criterion is as Von Misses Stress is concentration at

the support and edge of the wall panel. The experiment has

shown this criteria whereby the sample crushed at top and

bottom support. The maximum stress is much higher than the

experiment. Figure 4.11 show the linear relationship between

stress and load. Figure 4.12 show maximum stress for load

case DL10.



STRESS vs LOAD for

NUMERICAL ANALYSIS

PFe

0

15000

30000

45000

60000

75000

90000

105000

120000

135000

150000

0 100 200 300 400 500 600 700 800 900 1000 1100

Load (kN)

Str

ess (

kN

/m2

)

DL1

DL5

DL10

DL12

DL14

DL15

DL17

DL18

DL19

Fig. 4.11. Graph for numerical analysis on stress and different load cases

Fig. 4.12. Stress for load case DL10



5.0 CONCLUSION

The experiment results showed that the behaviour of the steel

fabric wire mesh reinforced concrete wall panel have similar

behaviour and characteristic as specified in BS 8110 and ACI

318. The average ultimate load for eight samples of wall

panels are 536.18 kN. By comparing with theoretical results

from ACI 318, BS 8110 Cl. 3.8.4.3 and BS 8110 Cl. 3.9.4.16

the ultimate load record from the experimental were less

84%, 192.37% and more 67.32%, respectively. Therefore, the

average strength capacity of shear wall is less than what is

specified in both of code of practice (ACI and BS 8110).

The deflection profile showed a single curvature pattern where

it bends at rear side. The maximum lateral displacement

ranges is about 9.67 mm and 2.75 mm which occurred at

distance 1050 mm (0.7H) and at 750 mm (0.5H) from the base

of the wall for sample PFe and PPe respectively. It was proved

that the theoretical studies of buckling by Euler with

maximum deflection should occur at center of the wall about

750 mm (0.5H) for pinned ends support.

Whereby, the maximum stress calculated using secant formula

has an average maximum stress record from the experiment

is 14105.50 kN/m2 less than theoretical calculation of 2.3%.

The strain increased linearly with the stress, the strain

recorded found to be very small and below the yield strain.

The steel fabric wire mesh B7 with two layers indicated that

the reinforcement is more adequate.

Beside that, there is no cracking occurrence on surface of wall

panel but the wall panel crushed at top and base of the wall.

Beayoune et all (2005), showed that when the load reached the

ultimate value a violent failure occurred by crushing at either

one or both of the panels [8].

Therefore, it can be conclude that, the objective of this study

has been achieved where the structural behaviour of wire

fabric reinforced concrete wall panel under eccentric loading

has been observed such as mode of failure, crack propagation

and deflection profiles as discussed. The experimental works

have proved the theory with some limitation on the test set up

and sample properties.

Since the wire fabric reinforced concrete wall panel is a new

trend in the construction in our country, this understanding

could provide sustainable development in promoting fast and

economic construction in the future.

5.1 RECOMMENDATION

There are some recommendations that will be useful to get a

better understanding on behaviour of the steel fabric wire

mesh reinforced concrete wall panel under eccentric loading.

i. The one way action or the direct axial load with

eccentric has predicted average agreement with

the theory.

ii. For future experiment on the same topic it is

recommended to look on

the different percentage of steel fabric in the wall

panel and slenderness ratio.

iii. The numerical analysis of different software

such as PROKON, ETAB, STAAD PRO and

LUSAS can be used as the numerical analysis.

iv. Study on the actual constructed wall panel

building could be more valuable inventory to

predict and confirmed the safety of the building.

v. It is recommended that higher reinforcement ratio

1.27% or maximum 4% of the section area as in

column design to be used in shear wall. Double

layer of steel fabric wire is advisable to use in the

construction of multi-storey building.

vi. Lateral cyclic loading test experiment to be

conducted for shear wall to determine the wall

strength subjected to horizontal loading such as

earthquake and wind loading.

REFERENCES

[1] Tunnel Formwork System (2007), Transkon Engineering Sdn Bhd (Brochure).(n.d) Kuala Lumpur.

[2] SIRIM, (2001) MS 145 Specification for Steel Fabric for the

Reinforcement of Concrete, Shah Alam, SIRIM Berhad. [3] British Standards Association (1997), BS 8110: Part 1. Structural

Use of Concrete, British Standard Institution [4] American Concrete Institute (1989), ACI 318 Building Code

Requirement for Reinforced Concrete, USA [5] Hamzah, S.H., Saari, N., Hamzah, A.H. and Marwi, M.S., (2005),

Understanding Reinforced Concrete Through Experiment, UPENA UiTM, ISBN 967-968-185-3, Shah Alam

[6] Hamzah, S.H., Kamarul Zaman, S.B., and Rajin, F., (2007), Wire Fabric Reinforced Concrete Wall Panel , World Housing Congress, Terengganu

[7] Wang, R., Elwi A.E, Hatzinikolas, M.A and Warwawuk, J.,

(1995) Tests on Tall Cavity Wall Subjected to Eccentric Loading”, the Seventh Canadian Mansory Symposium, June 5-7, 1995 Hamilton Ontario, Proceedings Vol 2, pp. 911-922

[8] PROKON (2008), PROKON Calculation Pad design software

Version W2.4.00. [9] Benayoune, A., Samad, A.A.A., Trikha, D.N., Ali, A.A.A. and

Ashrabor, A.A., (2005), Structural behaviour of

eccentrically loaded precast sandwich panels , Construction and Building Materials, 20, 713-724

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