TEMPLATE FOR ACADEMICA SCIENCE JOURNAL

AL-QADISIYAH JOURNAL FOR
ENGINEERING SCIENCES

Vol. 10 , No. 3

ISSN: 1998-4456

EXPERIMENTAL STUDY FOR BEHAVIOR OF (WASTE

CONCRETE FILLED STEEL TUBULER) COLUMNS SUBJECTED

TO A STATIC AXIAL LOADS

Zaid Ali Kadhim Alzaidi

Roads And Transport Engineering Department, College of Engineering, University of Al-Qadisiyah, Iraq

E-Mail: zaid.alzaidi@qu.edu.iq

Received on 17 April 2017 Accepted on 9 August 2017

Abstract: In this study, composite columns have been tested under axial load. The steel
tubes were filled with waste concrete to perform the composite action. The specimens
divided into two groups; square and circular columns. The diameter of the circular hallow
columns was 7.5 cm with 2mm thickness, while the dimension of the square hallow
columns was (7.5 cm × 7.5 cm) with 2mm thickness. For each group a column without
waste concrete filled steel tubular (W.C.F.S.T) was tested to act as a reference column.
Load-deflection curves were constructed for all specimens. The results indicate that the
waste concrete filled steel tube has more capacity due to the composite action. The
pattern of failure in circular sections was different from the failure pattern of the square
ones.

Keywords :W.C.F.S.T columns; Load -deflection curves; waste concrete; axial load;
pattern of failure .

INTRODUCTION AND LITERATURE REVIEW;

Steel materials have the advantage of high elasticity, while concrete material have the benefits of high

compressive quality and solidness. Composite section joins steel and concrete, properties together and

make new section that has the useful characteristics of both materials
[4]

.Figure 1 explains waste concrete

filled steel tubular (W.C.F.S.T) segments which comprises content of a steel tube filled with waste concrete.

The applied load on composite sections (resisted) by both steel and waste concrete by composite action; the

composite action depends on the strength of both the steel tube and concrete waste. In order to make the

concrete waste more intact, cement mortar was added to each layer of the fill to act as a bonding material.

The steel however, plays another role by acting as a confinement element and prevents the crushing of the

filler materials.

Utilizing of composite sections as a part of structures like multistory structures (bridges piers, piles …

and [so] far has been a promising systems because of their high (strength)limit, simple development,

imperviousness to fire, and flexibility.

mailto:zaid.alzaidi@qu.edu.iq

AL-QADISIYAH JOURNAL FOR
ENGINEERING SCIENCES

Vol. 10 , No. 3

ISSN: 1998-4456

1 Figure 1 . The waste concrete-filled steel tubular (W.C.F.S.T)

In 2009, Ghannam-[1] carried out study on the composite sections of rectangular cross area utilizing

eight filled scale samples. In his study, he investigated the strength of lightweight total cement filled steel

tube-shaped sections with typical weight total cement. All sections were tried up to the failure. In view of the

exploratory results and outline count the light weight total cement utilized as a part of composite segments

indicated satisfactory resistance in correlation with plan computation and the conduct of cement (C.F.S.T)

sections with ordinary cement was like those obtained from light weight concrete. In 2011, Fei-Yu et al- [2]

examined the behavior of composite sections in the presence of a gap between the filling materials and the

steel tube. A twenty one examples were tried and partitioned into two gatherings: (fourteen short segments

tested under only axial load, and seven bars subjected to flexure. The parameters studied in this research

were the gap sort (circumferential or circular top), and hole proportion. In 2012, Hafes et al-[3] exhibited a

hypothetical and investigational program for short compound sections subjected to stationary concentric and

erratic burdens, the test program included trial of six square C.F.S.T segments ,one of the exploratory factors

in the experiment is the applied load point. The investigational and hypothetical experiment reasoned that

the concentric load enhanced a definitive ability to around 250 – 275% while the eccentric loading expanded

a definitive ability to around 307 – 341%. the filling dilation action and the larger cross section area play

major role in increasing the capacity limit. In 2012, Nie et al-[4] displayed a trial concentrate on the C.S.F.T

sections conduct under torsion and pressure – torsion periodic loading. Eight (C.F.S.T) samples tried in the

experiment. The standards researched in the experiment kind of cross section, strengthen proportion and

applied loading level. as a conclusion, the torsional limit of C.F.S.T segments exposed to a Pressure –

Torsion loading expanded in low compressive force. Be that as it may, the torsional limit of C.F.S.T

segments diminished under the effect of great pressure loading. In 2013, Xiushu et al-[5] examined the

rectangular C.F.S.T segments exposed to eccentric load .the experimental program contained seventeen

rectangular C.F.S.T segments were tried under uniaxial and biaxial twisting burden. The standards

concentrated on were ; pressure quality of solid, steel quality. In 2015, Alaa Hasson et al-[6] Studied a

compound columns (square and circular) steel with hollow sections these filled with concrete. Specimens

investigated under the action of concentric and eccentric axial loads for one instance, which those section

tried horizontally likewise a beam to calculate the most bending resistant.

The objective of this research is to investigate the behavior of circular and square steel tube filled with

concrete waste under axial load, and to know the amount of resistance that can be added by the concrete

AL-QADISIYAH JOURNAL FOR
ENGINEERING SCIENCES

Vol. 10 , No. 3

ISSN: 1998-4456

waste in the case of use as a composite with the steel sections of all kinds for the purpose of benefiting from

these composite sections of the construction work.

1. EXPERIMENTAL WORK

six segments have been tested in this experiment ,divided into two groups ,one for (square) C.F.S.T

columns and the other for circular C.F.S.T columns. The segments used in the experiment are shown in

Figure 2.

Figure 2 . (Square and Circular) supports
.

Each group moreover was divided into two subdivision groups of three segments according to waste

filler. The first section of the first group is empty square section (no filler), the second section square is filled

with waste of concrete remaining on the sieve measuring (19 mm) as a coarse waste of concrete, the third

square is filled with waste of concrete transit sieve (4.75 mm) as a fine waste of concrete. The first of the

second set circular section is empty, the second filled with remnants of concrete remaining on the sieve

measuring 19 mm, and the third is filled with remnants of a circular concrete transit sieve (4.75 mm) .

Bearing in mind that the fill section in the form of layers with good compaction.

The empty steel segments (square and circular) experienced as stated by (ASTM A6) to find their yield

strength values. The sectional characteristics and yield strength of square and circular sections are

concluded as shown in table (1).

Table 1.Segments characteristics of empty( steel columns)

Steel section Dimensions (mm) Yield strength (MPa)

Square section 75×75×2 352

Circular section 75×2 327

The segments were tested under axial load by using the testing machine shown in Figure 3. Each

specimen was attached to a bearing plate from the bottom side to help applying the load uniformly to the

section. The lateral deflection at the middle of each section was captured by using the dial gauges as

explained in Figure 3.

AL-QADISIYAH JOURNAL FOR
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Vol. 10 , No. 3

ISSN: 1998-4456

Figure 3. Testing machine.

Each specimen was placed in the loading deck with high accuracy to ensure the alignment of the

column. The load then was applied monotonically and the reading of the load and corresponding dial gauges

readings were recorded. The characteristics of tested C.F.S.T columns (square and circular) are concluded

in Table (2) and Table (3) respectively.

Table2 . Characteristics of tested (square C.F.S.T) columns

Column
Dimensions

(mm)
Yield strength

fy (MPa)

S1 75×75×2 352

S2 75×75×2 352

S3 75×75×2 352

AL-QADISIYAH JOURNAL FOR
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Vol. 10 , No. 3

ISSN: 1998-4456

Table 3. Characteristics of tested (circular C.F.S.T) columns

Column
Dimensions

(mm)
Yield strength

(MPa)

C1 75×2 327

C2 75×2 327

C3 75×2 327

2. RESULTS

Based on investigational work explained in section 3. The results are summarized in Table 4 and

Table 5.

Table 4. Patterns of failure and Loads for( square W.C.F.S.T )columns

Column Waste Concrete
type description

Load
(KN)

Failure Pattern

S1 No filler 79 steel yielding at end span

S2
coarse waste of

concrete
86

yielding near the support due to compression

failure.

S3
fine waste of concrete

129
yielding near the support due to compression

failure.

Table 5. Patterns of failure and Loads for( circular W.C.F.S.T)columns

Column Waste Concrete
type description

Load
(kN)

Failure Pattern

C1 No filler 86 Buckling

C2
coarse waste of

concrete
139 Buckling

C3 fine waste of concrete 151 Buckling

2.1. LOAD - DEFLECTION CURVES:

The load - deflection curves for square waste filled steel tube columns and circular waste concrete

filled steel tube columns are explained in the figure 4 and figure 5 shown below.

AL-QADISIYAH JOURNAL FOR
ENGINEERING SCIENCES

Vol. 10 , No. 3

ISSN: 1998-4456

Figure 4. Load-displacement relationships of composite specimens of group(1) square W.C.F.S.T columns

Figure 5 . Load-displacement relationships of composite specimens of group(2) circle W.C.F.S.T columns

AL-QADISIYAH JOURNAL FOR
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Vol. 10 , No. 3

ISSN: 1998-4456

2.2. PATTERNS OF FAILURE

Figure 6 shows (square C.F.S.T) segments subjected to axial loading, the failure occurred because

waste concrete crushing and steel yielding ( at the loaded ends of the columns).The local yielding failure

was observed for (S1,S2,S3) segments due to the direct compression force from the loading deck.

Figure 6. Patterns of failure for square W.C.F.S.T columns subjected to axial loading.

Figure 7. Patterns of failure for circular W.C.F.S.T columns subjected to axial loading.

AL-QADISIYAH JOURNAL FOR
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Vol. 10 , No. 3

ISSN: 1998-4456

Figure 7 shows ( circular C.F.S.T) segments subjected to axial loading ,the failure was due to the

axial buckling at nearly the middle of the columns.

CONCLUSION;

Three composite square waste filled steel tube columns and three circular waste concrete filled steel tube

columns were investigated for their axial strength. from the obtained date, the following points can be

concluded:

1. It is appeared from the results that the (W.C.F.S.T) segments generally have a limited increasing in

axial load.

2. In axial loading case, the square W.C.F.S.T segments, the failure was due to steel yielding or waste

concrete crushing while in circular W.C.F.S.T sections the failure occurred because of the buckling

since the moment of inertia of the square segments (slightly) greater than the circular section.

buckling accrued first in circular section while the square section failed by yielding the steel material.

3- The results proved that the waste concrete can be reused as filler in composite columns since give a

reasonable strength has been obtained. On other word, this technique can be considered as

sustainable method.

REFFRENCES;

1. Ghannam S. Behavior of Composite steel Columns filled with Normal Concrete and Others filled with

Light weight Concrete. Proceeding of 3
rd

Engineering work Consultative Conference, Palestine , 2009.

2. Fei-Yu L., Lin-Hai H., and Shan-Hu H. Behavior of C.F.S.T short column and beam with initial concrete

imperfection. Journal of Constructional Steel Research, Vol. 67, Issue 12, pp , 2011.

3. Hafes L. M., Tawfic Y. R., Sdeek A. B., and Abdelazeem M. Theoretical and Experimental Study for

The Behavior of Short Composite Columns Tested Under Static Centric or Eccentric Loads. Journal of

Engineering Sciences, Assist University, Vol. 40, No 3, pp.639-655 , 2012.

4. Nie J., Wang Y., and Fan J. Experimental Study on seismic behavior of concrete filled steel tube columns

under pure torsion and compression–torsion cyclic load. Journal of Constructional Steel Research, Vol. 79,

pp. 115-126, 2012.

5. Xiushu Q., Zhihua C., and Guojun S. Experimental study of rectangular C.F.S.T Columns subjected to

eccentric loading. Thin-Walled Structures, Vol. 64, pp. 83-93, 2013.

6. Sa'ad Fahad Resan. Experimental Investigation of aluminum- lightweight concrete composite columns.

Basrah Journal for Engineering Sciences,Vol.14 , pp 13-26,2014.

7. Alaa Hadi Hameed Hassoon. Experimental study for the interaction curves of C.F.S.T columns subjected

to a static centric or eccentric loads. Journal of Thi-Qar University Vol.11 No.2 June ,2016.