IA final report-Xing Dan from MSE

School of Materials Science and Engineering

Report on industrial Attachment

SETSCO Services Pte Ltd

Name: Xing Dan

Matriculation no.: U1120725K

Submitted to: Prof. Hu Xiao (NTU Tutor)

Mr. Lawrence Lim( Supervisor)

Mr. Wilfred Tan Ah Siong(Supervisor)

Industrial Attachment Report (SETSCO Services Pte Ltd)

Table of Content

Abstract....................................................................................................................... 1

Acknowledgsments..................................................................................................... 2

Tables and figures....................................................................................................... 3

Chapter 1: Setsco introduction ...................................................................................1

1.1 History................................................................................................................2

1.2 introduction........................................................................................................ 3

1.3 Mechanical Technology Devision.....................................................................4

Chapter 2:Introduction of Introdustial attachment..................................................... 1

2.1 The project scope............................................................................................... 2

2.2 The engineering practice................................................................................................ 3

Chapter 3: Introduction of Samples and machines....................................................1

3.1 Samples of metal materials................................................................................2

3.2 Machines for mechanical testing....................................................................... 3

Chapter 4: Introdcution of BS4449.............................................................................1

4.1 BS4449:1997......................................................................................................2

4.2 BS4449:2005......................................................................................................3

Chapter 5: Introdcution of SS2................................................................................... 1

5.1 SS2 Part 3: 1987 ................................................................................................2


5.2 SS2 Part 1&2: 1999........................................................................................... 3

Chapter 6:The processes and procedures.................................................................................................................................. 1

6.1 The delivery of samples.................................................................................................................................. 2

6.2 The inspection of samples.................................................................................................................................. 3

6.3 The marking of rebars.................................................................................................................................. 4

6.4Tensile testing.................................................................................................................................. 5

6.5 Bending testing.................................................................................................................................. 6

6.6 Re-bending testing.................................................................................................................................. 7

6.7 The final report.................................................................................................................................. 8

References................................................................................................................... 1


Abstract

The introduction of Setsco Technology Pte. Ltd is very significant for this report,

which includes the history of Setsco company, the structure and the enterprise

culture. As I am assigned to Mechanical Technology Division, I mainly work and

study for the mechanical and metallurgic testing about buildings, it includes the

rebar, welded mesh fabric, couplers( control bar) and seven wire; we do tensile,

bend and re-bend with the machines and then output the final report based on the

required standard to inspect whether the metal materials can be eligible for the

building constructions or not.


Acknowledgments

The IA student is so thankful of the support of Setsco Technology Pte. Ltd

supervisor, Mr. Wilfred Tan Ah Siong. The professional experience from Mr.

Wilfred Tan Ah Siong has a significant effect and help to IA student in the region

of the Mechanical testing. Furthermore, the appreciation of IA student extends to

his colleaguesMr. Lawrence Lim because of the encouragements. Finally, the IA

student shows the deep thanks to the NTU tutor, Prof. Hu Xiao for his warm

support.


Tables and figures

Figures of Chapter 1: Setsco introduction

Figures of Chapter 3: Introduction of Samples and machines

Tables and figures of Chapter 4: Introdcution of BS4449 and Chapter 5:Introdcution of SS2

Figures of Chapter 6:The processes and procedures


Chapter 1: Setsco introduction

1.1 HistoryIn 1963, Setsco Services Pte Ltd was founded when the services were performedunder the Industrial Research Unit (IRU) of the Economic Development Board(EDB).

In 1981, Setsco Services Pte Ltd was set up by SISIR to offer commercial servicesto the industry as a wholly-owned subsidiary of SISIR.

From 1987 to 1989, Setsco Services Pte Ltd was corporatised and became awholly-owned subsidiary of Keppel Corp.

In 1995, Setsco Services Pte Ltd owned its first overseas subsidiary in Malaysia.

In 1997, Setsco Services Pte Ltd was Located at Teban Gardens Crescent and hasits own building.

In 2002, Setsco Services Pte Ltd offered a respresentative office in Ho Chi Minh,Vietnam.

In 2003, Setsco Services Pte Ltd was a wholly-owned subsidiary of VICOM Ltd.

In 2013, Setsco Services Pte Ltd set up a new 4-floor building as SetscoHeadquarters at Teban Gardens Crescent as below figure 1.


Figure 1. The Setsco Headquarters housed in new 4-storey building

1.2 Introduction

Setsco Corporate Profiles

Setsco Services Pte Ltd (SETSCO), with more than 30 years of experience, is oneof Singapore’s largest testing and inspection companies accredited by theSingapore Accreditation council-Singapore Laboratory Accreditation Scheme(SAC-Singlas) to ISO/IEC 17025, ISO/IEC 17020 and ISO/IEC Guide 65. Basedin Singapore with a global clientele network, it serves a wide spectrum ofindustries such as electronics, biotechnology, aerospace, marine & offshore, oil &petrochemical, engineering & construction and provides specialized services in thefields of mechanical, chemical, biological, civil engineering and non-destructivetesting. Setsco Services Pte Ltd also offer a comprehensive range of calibration andmeasurement services to meet the present and diversified needs of the industries.

Setsco Services

By industry, the Setsco services include aerospace, chemicals, calibration &measurement, consumer goods, construction, electrical & electronics, environment,


food & biology, industrial & manufacturing, medical & pharmaceutical, oil & gas,petrochemical.

By category, the services have product certification, inspection, training, testing,calibration & measurement and consultancy.

Setsco Vision

To be the leading technology center in the region.

Setsco Mission

Setsco Services Pte Ltd provides assessment and consultancy in the field of scienceand engineering through testing, inspection, applied research and technologyapplications with the aim of achieving quality and safety for the industry.

Setsco Values

Setsco is committed to provide professional services and excellent customerservice.Setsco deploy state-of-the-art technology in strengthening the competitiveness.Setsco encourages teamwork and provide ample opportunities for the staff’spersonal growth and development.

1.3Mechanical & Metallurgy TestingSetsco provides a wide range of metallurgical testing services on metals and alloysto meet industrial needs. Our clients are from aerospace, petrochemical, marine,manufacturing, fabrication and construction industries.

Setsco’s metallurgists are experienced in establishing component / equipmentfailure due to various causes such as fatigue, tensile overloading, wear, elevatedtemperature exposure, corrosion and manufacturing defects. Our failure analysisresults have been used by clients to prevent further occurrence of such failures.

Range of Metallurgical Services

Failure investigation on components & equipmentMaterials evaluation by metallurgical examination


Coating thickness, grain size & ferrite measurementsIn-situ metallography on components or equipment on site or in the laboratoryCorrosion investigation, corrosion prevention advisory services & materialselectionMacro & Micro ExaminationCase Depth / Decarburisation Depth MeasurementInclusion ChecksAnalysis / Coating Measurement for PCB

Mechanical Testing

Materials: Metal, Polymer, Timber, TextileHardness Tests (Brinell, Rockwell, Vickers)Tensile, Bend, Shear, Impact, Compressive & Flexural TestCreep, Fatigue & WearHydrostatic Pressure TestFlow Measurement & Mechanical Load TestVicat Test, Heat Distortion Test & Stress Relief TestEndurance & Mechanical Load TestMechanical Testing for Welder & Procedure Qualification TestWelder Test

Chapter 2:Introduction of Introdustialattachment2.1The project scope:Mechanical & Metallurgical TestingMechanical testing including tensile, bending and re-bending testing ofreinforcement steel bar, welded mesh testing, fabric testing, seven wire testing, etc.

2.2The engineering practice:Mechanical testing including tensile, bending and re-bending testing ofreinforcement steel bar, welded mesh testing, fabric testing, seven wire testing, etc.We mainly do these tensile, bending and re-bending testing of the reinforcement


steel bars which mainly part some kinds of diameter 10, 13, 16, 20, 25, 28, 32 and40 size as we always do tensile, bending and re-bending testing. The welded meshtesting is similar to three kinds testing (tensile and bending testing) but the testingmachine is different because of different conditions containing different diametersize, length and etc. The fabric testing mainly is the tensile testing as same thetensile testing of the reinforcement steel bars. The seven wire testing mainly partthe breaking load testing and full test.

Chapter 3: Introduction of Samples andmachines

3.1 Samples of metal materialsRebar is a common steel bar or mesh of steel wires commonly used as a tensiondevice in reinforced concrete and reinforced masonry structures, to strengthen andhold the concrete in compression. The surface of the rebar may be patterned toform a better bond with the concrete.

Figure of rebars

Welded Mesh Fabric is regularly used for concrete slab construction, such asroadways, in curved structures such as in domes and as bonding fabric for gunite.The cost, time and labor savings of welded wire fabric reinforcing offers anadvantage over traditional tied rebar.


Figure of welded mesh fabric

Coupler is made of two control bars as two control bars connect with each othertogether. Control bar is the rebar, but the coupler and control bar have differenttesting ways compared with the rebar. The testing for the coupler mainly check thebending, the maximum load and tensile strength.( control bar for the maximumload and tensile strength)

Figure of coupler ( control bar)

Seven wire is made of seven round bars with diameter of 4 and 6. The testing forseven wire mainly inspect the maximum load, elongation and Young modulus.


Figure of seven wire

3.2 Machines for mechanical testing

The machines for mechanical testing mainly include 25 Ton( Zwick) UTM, 120

Ton( Instron) UTM and 150 Ton( Instron), bending and re-bending machines.

For 25 Ton UTM, its maximum load is 25 tons and it mainly test fabric( about 350-

400mm long) and plain rebar( 350mm long).


Figure of 25 Ton UTM

For 120 Ton UTM, its maximum load is 120 tons and it mainly test ribbed bars and

coupler( control bar).



For 150 Ton UTM, its maximum load is 150 tons and it mainly test ribbed

bars( the rebars with diameter less than 16mm is not recommended), seven wire

and coupler( control bar).


Bending machine is used to bend the rebars and fabric to 160-180 degree based on

the standard.


Figure of the bending machine

Re-bending machine is used to re-bend to 70 degree from 90 degree and 23 degreefrom 45 degree based on the required standards.

Figure of re-bending machine


Chapter 4: Introdcution of BS4449

The British Standard (BS)BS 4449 has been amended and is the British standard that specifies therequirements for ribbed weldable reinforcing steel used for the reinforcement ofconcrete structures. BS 4449 covers steel delivered in the form of bars, coils andde-coiled products.

For the purposes of this British Standard, hot rolled deformed bar and cold workdeformed bar. Hot rolled deformed bar means that a bar that has been so shapedduring hot rolling that it conforms to either the geometrical or the performance testclassification; cold work deformed bar is defined that a bar that has been coldworked to conform to the property requirements of this British Standard and thatconforms to either the geometrical or the performance test classification. The barincludes longitudinal rib (a uniform continuous protrusion parallel to the axis ofthe bar, before twisting in the case of cold twisted bars) and transverse rib (any ribon the surface of the bar other than a longitudinal rib). The range of nominal sizesof bars shall be from 6 mm to 50 mm.

4.1BS4449: 1997It covers plain round steel bars in grade 250(grade 250 means that the minimumvalue of the yield strength is 250 MPa), and deformed (type 1 and type 2) highyield steel bars in grade 460(grade 460 means that the minimum value of the yieldstrength is 460 MPa), the latter in two ductility categories, 460A and 460B.

Type 1: Either a plain square twisted bar or a plain chamfered square twisted bar,with a pitch of twist not greater than 14 times the nominal bar size.Type 2: A bar with transverse ribs of a substantially uniform spacing not greaterthan 0.8for as-rolled deformed bars or 1.2 for cold twisted bars; having a meanarea of ribs (per unit length), above the core of the bar projected on a plane normalto the axis of the bar, of not less than 0.15 mm2/mm, where is the nominal bar size(in millimetres).

Grade 460A: Bars shall have two or more series of parallel transverse ribs with thesame angle of inclination and the same direction for each series as below figure.


Figure A: Example of rib pattern of grade 460A with four transverse rib series

Grade 460B:Bars shall have two or more series of parallel transverse ribs. For barswith two or three rib series, one of the series shall be at a contrary angle to theothers; and for bars with four rib series, two of the series shall be at a contraryangle to the others.

Figure B: Example of rib pattern of grade 460B with four transverse rib series

Figure of samples about 460A and 460B

The diameter size of the bars in grade 250 is from 8 to 16 and that with grade 460ranges from 8 to 40.


Table 1 the nominal sizes of the bars in grade 250 and 460

The cross sectional area, mass and tolerance

The cross sectional area and mass of the bars shall be calculated on the basis thatsteels have a mass of 0.00785 kg per square millimetre per metre run.

Table 2 the cross sectional areas and mass per meter runs of nominal sizes

Table 3 the tolerance on mass per meter run of the nominal sizes

Before mechanical testing, to measure the length and weight of sample rebars andcalculate the mass per meter run and compare with the requirement of mass permeter run and then achieve the tolerance, if the value is in the range of therequirement of tolerance, the sample rebar is passed, otherwise, it is failed.

Chemical composition


To measure the chemical composition and calculate the carbon equivalent valueand compare with the requirement of the carbon equivalent value to make surewhether the samples are eligible or not for building construction.

Table 4 the chemical composition of steel grade 250 and 460

Table 5 the maximum carbon equivalent value in grade 250 and 460

Tensile properties

The yield strength Re, stress ratio Rm/Re, and elongation at fracture A5, of steelobtained from testspecimens selected, prepared and tested shall be as specified in Table 6.

Table 6 tensile properties

For total elongation at maximum force Agt, Measurements shall be made andrecorded and available for inspection, but if the total elongation is below theminimum value specified in Table 6, this shall not be a cause for non-conformitywith this British Standard.


Bend testing

For the sample rebars in grade250,no bend testing is done. For the sample rebarsin grade 460, the load with 3 times diameter of 6, 8 and 10 is used to bend thesample rebars with diameter 6, 8 and 10; for the diameter 16 and 20, the load with5 times diameter of 16 and 20 bends them and the load with 6 times diameter of 25,32 and 40 bend them for the diameter 25, 32 and 40 by bending machine. All ofdegree is bended to 160 to 180.

Re-bend testing

a) The specimen shall be bent through an angle of 45 degree, using a former ofdiameter and at a temperature of between 5℃ and 30℃ so as to produce acontinuous and uniform bending deformation (curvature) at every section of thebend.The test shall be conducted either:1) on a bending machine in which the test specimen is supported by plain smoothsurfaces or rolls thatdo not resist longitudinal movement of the test piece; or2) on a three-point hydraulic bending machine.We use the machine two to re-bend the sample rebars bended. The test machineshall be serviceable and able to impart a constant load to the specimen, and shall bewithout impact effect. The maximum bending rate shall be 3 r/min or equivalent.b) The test specimen shall be heated to 100℃ and maintained at this temperaturefor at least 30 min.c) The test specimen shall be allowed to cool to a temperature of between 5℃ and30℃, and partiallyre-straightened by a steadily applied force, through at least 23 degree, on a bendingmachine.

In grade 250, the load with 2 times diameter of all sizes is used to re-bend themfrom 45 degree to 23 degree; in grade 460, the load with 5 times diameter of thesesizes when the diameter of sample rebars is less than 16mm is used to re-bendthem from 45 degree to 23 degree, the load with 7 times diameter of these samplerebars more than 16mm re-bend them from 45 degree to 23 degree.


Figure of re-bend based on BS4449:1997

4.2 BS4449: 2005The standard contains provisions for three steel grades, all of 500 MPa( theminimum value of the upper yield strength for BS4449: 2005 is 500 MPa)characteristic yield strength, but with different ductility characteristics. The threegrades are B500A, B500B and B500C.


Figure 1 the BS 4449: 2005 in grade B500A, B500B and B500C

Re is yield strength, Rm/Re is Ratio of tensile strength/Yield strength, Agt isPercentage total elongation at maximum force, Re,act/Re,nom (where appropriate)isRatio of actual to specified value of yield strength.


Figure 2 the sample rebar in grade 500


BS4449: 2005 is similar to BS4449: 1997.Diameter size Mass per meter run10 0.61712 0.88816 1.58020 2.47025 3.85032 6.31040 9.860

The tolerance is from -6% to +6% as the diameter size is equal or less than 8mmand the tolerance is from -4.5% to +4.5% when the diameter size is more than8mm.Before mechanical testing, to measure the length and weight of sample rebars andcalculate the mass per meter run and compare with the requirement of mass permeter run and then achieve the tolerance, if the value is in the range of the


requirement of tolerance, the sample rebar is passed, otherwise, it is failed.

Tensile properties

From the figure 1 of BS4449: 2005, Re yield strength, Rm/Re Ratio of tensilestrength/Yield strength, Agt Percentage total elongation at maximum force areseparately 500, 1.08(min) and 5.09(min) for B500B of BS4449: 2005, because thesample rebars we tested almost belong BS4449: 2005(B500B),so we mainlyremember these data, if the customers demand test with BS4449: 2005( B500A orB500C),we check them with the data of yield strength, ratio of tensile/yieldstrength and total elongation percentage at maximum force.

Re-bend testing

b) The specimen shall be bent through an angle of 90 degree, using a former ofdiameter and at a temperature of between 5℃ and 30℃ so as to produce acontinuous and uniform bending deformation (curvature) at every section of thebend.The test shall be conducted either:1) on a bending machine in which the test specimen is supported by plain smoothsurfaces or rolls thatdo not resist longitudinal movement of the test piece; or3) on a three-point hydraulic bending machine.We use the machine two to re-bend the sample rebars bended. The test machineshall be serviceable and able to impart a constant load to the specimen, and shall bewithout impact effect. The maximum bending rate shall be 3 r/min or equivalent.b) The test specimen shall be heated to 100℃ and maintained at this temperaturefor at least 1 hour.c) The test specimen shall be allowed to cool to a temperature of between 5℃ and30℃, and partiallyre-straightened by a steadily applied force, through at least 70℃, on a bendingmachine.In grade B500B from BS4449: 2005, the load with 4 times diameter of these sizeswhen the diameter of sample rebars is less than 16mm is used to re-bend themfrom 90 degree to 70 degree, the load with 7 times diameter of these sample rebarsmore than 16mm re-bend them from 90 degree to 70 degree.

Chapter 5: Introdcution of SS2


Singapore Standard

The Singapore Standard Specification for ‘Steel for the reinforcement of concrete’was prepared by the Technical Committee on Steel under the direction of theBuilding Materials Product Standards Committee.

We always do mechanical testing with Singapore Standard 2( shorten for SS2). Itincludes SS2 part 1: 1999, SS2 part 2: 1999 and SS2 part3: 1987. SS2 part 1&2:1999 is a revised edition of SS 2 : Part 3 : 1987 (formerly known as SS 2 : 1987)and consists of the following two parts:- Part 1. Plain bars (Steel grade 300( the minimum value of the upper yield strengthis 300MPa))- Part 2. Ribbed bars (Steel grade 500( the minimum value of the upper yieldstrength is 500MPa))

Cold worked steel bars are not covered in Parts 1 and 2 of SS 2. For SS2 Part 3:1987, the reinforcement steel bars cover plain round steel bars in grade 250( theminimum value of lower yield strength is 250MPa) and high yield deformed barsin grade 460( the minimum value of lower yield strength is 460MPa).

5.1 SS2 part3: 1987



Figure 1 the cross sectional area and mass per meter run from SS2 part 3: 1987

The tolerance is from -8% to +8% as the diameter size is equal or less than 10mmand the tolerance is from -5% to +5% when the diameter size is more than 10mmand equal or less than 20, the value is from -4% to +4% as the diameter size ismore than 20.



Figure 2 the rebar in grade 460

Figure 3 bend and re-bend based on SS2 : 1987

5.2 SS2 part 1 & 2: 1999The cross sectional area, mass and tolerance

The cross sectional area and mass of the bars shall be calculated on the basis that


steels have a mass of 0.00785 kg per square millimetre per metre run.

Figure 1 the cross sectional area and mass per meter run from SS2 part 1&2: 1999

The tolerance is from -8% to +8% as the diameter size is equal or less than 10mmand the tolerance is from -5% to +5% when the diameter size is more than 10mmand equal or less than 22, the value is from -4% to +4% as the diameter size ismore than 22.


Chemical composition

To measure the chemical composition and calculate the carbon equivalent valueand compare with the requirement of the carbon equivalent value to make surewhether the samples are eligible or not for building construction.


Figure 2 the chemical composition of SS2 and the maximum CE% Part 1&2: 1999

Tensile properties

The yield strength Re, stress ratio Rm/Re, and elongation at fracture A5, of steelobtained from test specimens selected, prepared and tested shall be as specified inTable 1.

Table 1 tensile properties of SS2 part 1&2: 1999

For total elongation at maximum force Agt, Measurements shall be made andrecorded and available for inspection, but if the total elongation is below theminimum value specified in Table 1, this shall not be a cause for non-conformitywith this Singapore Standard.

Bend testing

For SS2 part 1: 1999 of sample rebars in grade 300, the load with 2 times diameterof 6, 8 and 10 is used to bend the sample rebars with diameter 6, 8 and 10; for thediameter 12, the load with 2.5 times diameter of 12 bends them and the load with 3times diameter of 16 and 20 bend them for the diameter 16 and 20 by bendingmachine. All of degree is bended to 160 to 180.

For SS2 part 2: 1999 of sample rebars in grade 500, the load with 3 times diameterof 6, 8 and 10 is used to bend the sample rebars with diameter 6, 8 and 10; for thediameter 12, the load with 4 times diameter of 12 bends them and the load with 5times diameter of 16 and 20 bends them for the diameter 16 and 20; the load with 6times diameter of 25, 32 and 40 bend them for the diameter 25, 32 and 40 bybending machine. All of degree is bended to 160 to 180.

Re-bend testing for SS2 part 2: 1999

c) The specimen shall be bent through an angle of 90 degree, using a former ofdiameter and at a temperature of between 5℃ and 30℃ so as to produce a


continuous and uniform bending deformation (curvature) at every section of thebend.The test shall be conducted either:1) on a bending machine in which the test specimen is supported by plain smoothsurfaces or rolls that do not resist longitudinal movement of the test piece; or4) on a three-point hydraulic bending machine.We use the machine two to re-bend the sample rebars bended. The test machineshall be serviceable and able to impart a constant load to the specimen, and shall bewithout impact effect. The maximum bending rate shall be 3 r/min or equivalent.b) The test specimen shall be heated to 100℃ and maintained at this temperaturefor at least 30 min.c) The test specimen shall be allowed to cool to a temperature of between 5℃ and30℃, and partially re-straightened by a steadily applied force, through at least 70degree, on a bending machine.

For SS2 part 2: 1999 of sample rebars in grade 500, the load with 5 times diameterof 6, 8 and 10 is used to re-bend the sample rebars with diameter 6, 8 and 10; forthe diameter 12, the load with 5 times diameter of 12 re-bends them and the loadwith 8 times diameter of 20 and 25 re-bends them for the diameter 20 and 25; theload with 10 times diameter of 32 and 40 re-bend them for the diameter 32 and 40by bending machine. All of degree is re-bended from 90 degree to 70 degree.

Figure of bend and re-bend based on SS2 part 1&2: 1999


Chapter 6: The processes and proceduresof mechanical testing6.1 The delivery of samplesThe delivery of samples includes two ways: one is that the customers deliver theirsamples to our workplace and another one is that we go to logistics to take samplesdelivered.

6.2 The inspection of samplesWe take the samples and then must inspect them with the letters to make sure thatthe diameter size, quantity and logo, etc match with the writing on the letters. Thetags also help us provide the key to identifying the samples. A typical tag showsthe number of pieces in a shipment of each sample. It also shows that the materialsused to manufacture the samples conform to standards for mechanical testing.Sometimes, we need the mill test reports for some strict testing requirements, theCertified mill test reports typically accompany each shipment of samples. The millreports certify that the sample conforms to the project specifications includingtensile testing, bending and re-bending and reveals the chemical composition of thesamples. After the inspection of samples, we need to take photos to record andsave. And write job number and date received, if the customer need to witness forthis testing, we can help them book a date for witnessing.


Figure of samples of rebars

6.3 The marking of rebarsFor tensile testing of rebars, we must marking for the rebars, the marking mainlyhelp measure the elongation and Agt, then check if the rebar is passed or failed.Before marking of rebars, we must measure the length, the length of rebars withdiameter size less than 32 is 600mm, the length of D32 is 640mm and the length ofD40 is 800mm based on the standard. If the length is too short, the customers needto send new samples; if the length is too long, we must cut to the required length.


Figure of the rebar cut by the cutting machine

Figure of the rebar cut

To measure the length and weight of rebars and record them, and then to startmarking.

The methods of marking of rebars part two ways, the SS2: 1999, SS2: 1987 andBS4449: 1997 have one same marking way( the first one); and BS4449: 2005exists another marking way( the second one).


For the first one, we mark the first point with 100mm from one side end of therebar with the diameter equal or less than 13mm, and mark second point from firstpoint with 5 times diameter length and then mark third point behind second pointmarked and then mark points from third point till another side end of the rebar. Forthe rebar with diameter more than 13mm, we mark two points from two side endswith 130mm, and then mark two points with 5 times diameter length from thesetwo points, then mark points behind the new two points marked and then till thelength of the middle two points is less than the 5 times diameter length and balancethe two points to mark two points.

For the marking of fabric, the method is similar to the rebar, but the length fromthe first point to the one side end is 60mm.

Figure of rebars marked


Figure of the marking of fabrics


Figure of marking of A8 fabric

The second marking is for BS4449: 2005

Figure of the rebar marked with BS4449: 2005


Marking way is following steps:

Step 1. Measure the length of the rebar and find the center, the mark a point on it.Step 2. Mark 12 points, 6 points on the left of the center and another 6 points onthe right of the center, the interval distance is 25mm between of every two pointsfor T10 to T32, for T40, it needs 4 more points( 2 points left and 2 points right).Step 3. Mark 2 more points on two sides( 1 left and 1 right), for belowT20(including T20), the distance is 20mm, and for above T20, the interval distanceis the diameter of the rebar.

For marking rebars of BS4449: 2005, we invent the Manual Marking Machine(MMM).

Figure of Manual Marking machine

To compare with the marking by hands, the MMM has several advantages asfollowed:

First, save marking time as the marking and hammering can be processed at thesame time.Second, reduce the human errors and improve the precision.


Third, promote the safety and security.

Some ideas of improvements are:

If the “pump” pressure system of the bending machine can be used for hammering,it can save more time and lower the effect on the tensile testing(especially for therebar with small diameter) as it can hammer all points with same load.

To adjust the height of the bottom instead of opening hand rail, it can promote thesafety and make the process easier.

If the last two points on the two sides can be adjusted with the required intervaldistance, I think it is perfect.

If the above improvements are input to data logger, and record the data for T10 toT40 by testing and link the data logger to the computer, the auto marking machineis born, like the tensile testing machine.

6.4 Tensile testingBased on different height, we need to adjust the height of the tensile machine, andput in the rebars or seven wire, then clamp the clamps to make sure that the rebars,seven wire, coupler and control bars cannot drop when the tensile testing is inprogress. Till broken, brush the dust and then unclamp the clamps to take out them,and measure the elongation, other data are recorded in the computer, for seven wireand control bars, we record the load, then measure the tensile strength and theyoung modulus with the plot of stress vs strain to check if they are failed or not.For coupler, we need to measure the bend degree and then measure the tensilestrength.


Figure of tensile machine

Figure of couplers for measuring the bend degree


Figure of broken of couplers


Figure of the broken of fabric

Figure of broken of seven wire


6.5 Bending testingWe use bending machine to bend the rebars. Based on different standard, we bendthem to different degree.

Figure of the bending machine for the rebars with diameter less than 32mm


Figure of the bending machine for rebars with diameter 32 and 40

Figure of rebars bended


The rebar bended as below figure is failed.

Figure of failed bend rebar

6.6 Re-bending testingAfter heating the rebars, we re-bend them with re-bending machine based ondifferent standards to different degrees.


Figure of re-bending machine

Figure of whiteboard( 45 degree and 23 degree on the top, 90 degree and 70 degreeon the bottom)


Figure of re-bending from 90 degree to 70 degree

Figure of re-bending from 45 degree to 23 degree

The rebar re-bended as below figure is failed.


Figure of failed re-bend rebar

6.7 The final report

We complete the whole processes as above, and then type the data to the computerto calculate the data based on the required standards to output the final report andre-check the report to make sure the reports have no problems. Finally, we fax orsend the final report to customers.


References

Data and photos from the website of Setsco technology company

Data from the website of Natsteel company in Singapore

Data from http://www.lion.com.my/WebOper/Steel/AmsteelMills.nsf/Concrete/

Data from the British Standard and Singapore Standard

Some Tables and figures from google searching

Documents

IA final report-Xing Dan from MSE