2017 BOOK OF FULL-TEXT PROCEEDINGS IATS 2017web.hitit.edu.tr/dosyalar/yayinlar/[email protected] BOOK OF FULL-TEXT PROCEEDINGS IATS 2017 ISBN: 978-605-82017-0-5

2017 BOOK OF FULL-TEXTPROCEEDINGS

IATS 2017

ISBN: 978-605-82017-0-5

Organized byrganized b

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Book of Full Text of the 8th InternationalAdvanced Technologies Symposium(IATS) 2017

Editors

Prof. Dr. Niyazi Özdemir

Prof. Dr. Hikmet Esen

Published, 2017

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ISBN: 978-605-82017-0-5

SCIENTIFIC COMMITTEE

Prof. Dr. Abdelkarim Mekki, King Fahd University of Petroleum Minerals

Prof. Dr. Abderrahmane Bairi, University Paris Ouest LTIE-GTE

Prof. Dr. Abdulkadir Şengür, Fırat University

Prof. Dr. Adem Kurt, Gazi University

Prof. Dr. Adrian Briggs, University of London

Prof. Dr. Ahmet Çetin, Bingöl University

Prof. Dr. Ahmet Ziyaettin Sahin, King Fahd University

Prof. Dr. Ahmet Hasçalık, Fırat University

Prof. Dr. Ali Chamkha, Kuwait University

Prof. Dr. Ali Sekmen, Tennessee State University

Prof. Dr. Alireza A. Ardalan, Tehran University

Prof. Dr. Andrew Collop, The University of Nottingham

Prof. Dr. Andrzej Trytek, Rzeszow University of Technology

Prof. Dr. Asaf Varol, Fırat University

Prof. Dr. Attieh Alghamdi, King Abdulaziz University

Prof. Dr. Beşir Dandıl, Fırat University

Prof. Dr. Byeong-Kwon JU, Korea University

Prof. Dr. Cengiz Tatar, Fırat University

Prof. Dr. Cengiz Yıldız, Fırat University

Prof. Dr. Christian Wenger, Innov. for High Performan. Microelectronics

Prof. Dr. Chung Gwıy-Sang, Ulsan University

Prof. Dr. D. S. Patıl, North Maharashtra University

Prof. Dr. Darina Arsova, Institute of Solid State Physics, Sofia

Prof. Dr. Denis Nıka, Moldova University

Prof. Dr. Dursun Özyürek, Karabük University

Prof. Dr. Eiyad Abu-Nada, Hapshemite University

Prof. Dr. F. M. Amanullah, King Saud University

Prof. Dr. Fatih Kurugöllü, Queen's University Belfast

Prof. Dr. Fernando Gutierrez, University Polytechnic of Madrid

Prof. Dr. Ferhat Gül, Gazi University

Prof. Dr. Fumihiko Hırose, Yamagata University

Prof. Dr. Hanbey Hazar, Fırat University

Prof. Dr. Hanifi Güldemir, Fırat University

Prof. Dr. Hasan Efeoğlu, Atatürk University

Prof. Dr. Hüseyin Altun, Fırat University

Prof. Dr. Ikhlas Abdel-Qader, Western Michigan University

Prof. Dr. Ioan Pop, University of Cluj

Prof. Dr. İbrahim Dinçer, University of Ontorio

Prof. Dr. İbrahim Türkoğlu, Fırat University

Prof. Dr. İsmail Fidan, Tennessee Tech University

Prof. Dr. Jay Khodadadi, Auburn University

Prof. Dr. Jingkun XU, Technology Normal University

Prof. Dr. Juan Carlos Martinez-Anton, Complutense University of Madrid

Prof. Dr. Juan Mario Garcıa De Marıa, University of Madrid

Prof. Dr. K.W. Chau, Hong Kong Polytechnic University

Prof. Dr. Khasan S. Karimov, GIK Institute

Prof. Dr. Khanlar Baghırov, Cumhuriyet University

Prof. Dr. M. Hasnaoui, University Cadi Ayyad

Prof. Dr. Majumdar J. Datta, Indian Institute of Tehcnology Kharagpur

Prof. Dr. Marco Antonio Schiavon, Universi. Federal de São João Del Rei

Prof. Dr. Marga Jann, Girne American University

Prof. Dr. Mariam Ali S A Al-Maadeed, Qatar University

Prof. Dr. Mehmet Çiftci, Bingöl University

Prof. Dr. Mehmet Esen, Fırat University

Prof. Dr. Messaoud Saıdanı, Conventry University

Prof. Dr. Moghtada Mobedi, İzmir High Technology Institute

Prof. Dr. Mohamed Bououdına, Univeristy of Bahrain

Prof. Dr. Muhammad Hassan Sayyad, Ghulam Ishaq Khan Institute

Prof. Dr. Mustafa Boz, Karabük University

Prof. Dr. Mustafa Canakci, Kocaeli University

Prof. Dr. Mustafa Kurt, Marmara University

Prof. Dr. Mustafa Taşkın, Mersin University

Prof. Dr. Müjdat Çağlar, Eskişehir Anadolu University

Prof. Dr. Najib Laraqi, University Paris Ouest LTIE-GTE

Prof. Dr. Nizamettin Kahraman, Karabük University

Prof. Dr. Nourah AL Senany, King Abdulaziz University

Prof. Dr. Oğuzhan Keleştemur, Fırat University

Prof. Dr. Orhan Aydın, Karadeniz Technical University

Prof. Dr. Osman Dayan, Çanakkale Onsekiz Mart University

Prof. Dr. Ömer Keleşoğlu, Fırat University

Prof. Dr. Rachid Bennacer, University of Cergy Pontoise

Prof. Dr. Ramazan Çıtak, Gazi University

Prof. Dr. Ramazan Kaçar, Karabük University

Prof. Dr. Ramazan Köse, Dumlupınar University

Prof. Dr. Ramazan Solmaz, Bingöl University

Prof. Dr. Ramin Yousefı, Islamic Azad University

Prof. Dr. Recep Çalın, Kırıkkale University

Prof. Dr. Ridha Ben Yedder, Université de Québec

Prof. Dr. R. H. Al Orainy, King Abdulaziz University

Prof. Dr. Saad Hamad BINOMRAN, King Saud Univeristy

Prof. Dr. Salih Yazıcıoğlu, Gazi University

Prof. Dr. Sami Ekici, Fırat University

Prof. Dr. Serdar Salman, National Defense University

Prof. Dr. Serdar Osman Yılmaz, Namık Kemal University

Prof. Dr. Sermin Ozan, Fırat University

Prof. Dr. Servet Tuncer, Fırat University

Prof. Dr. Suat Yılmaz, Istanbul University

Prof. Dr. Subhash Chand, National Institute of Technology

Prof. Dr. Süleyman Gündüz, Karabük University

Prof. Dr. Syed Ali Rizwan, National University of Sci.& Tech.,

Prof. Dr. Şahin Albayrak, DAI-Labor, Technische Universitat Berlin

Prof. Dr. Şükrü Karataş, Kahramanmaraş, Sütçü İmam University

Prof. Dr. Şükrü Talaş, Afyon Kocatepe University

Prof. Dr. Tahir I. Khan, University of Bradford

Prof. Dr. Tanmay Basak, Indian Institute of Technology

Prof. Dr. Ufuk Teoman Aksoy, Fırat University

Prof. Dr. Ulvi Şeker, Gazi University

Prof. Dr. Vítor António Ferreira da Costa, Universidade de Aveiro

Prof. Dr. Wazirzada Aslam Farooq, King Saud University

Prof. Dr. Weite Wu, National Chung Hsing University

Prof. Dr. Yasin Varol, Fırat University

Prof. Dr. Yetkin Tatar, Fırat University

Prof. Dr. Yu Bo, China University of Petroleum

Prof. Dr. Yusuf Al-Turkı, King Abdulaziz University

Prof. Dr. Yusuf Öztürk, San Diego State University

Prof. Dr. Zaıtsev, D. D., Moscow State University

Prof. Dr. Zaki Mohamed, Taif University

Prof. Dr. Zeyad A. Alahmed, King Saud University

Prof. Dr. Zoubir Zouaoui, Glyndwr University

Assoc. Prof. Dr. Aykut Çanakçı, Karadeniz Technical University

Assoc. Prof. Dr. Bilal Alataş, Firat University

Assoc. Prof. Dr. Canan Aksu Canbay, Fırat University

Assoc. Prof. Dr. Cebeli Özek, Fırat University

Assoc. Prof. Dr. Cengiz Öner, Fırat University

Assoc. Prof. Dr. Çetin Özay, Fırat University

Assoc. Prof. Dr. Cihan Varol, Sam Houston State University

Assoc. Prof. Dr. Erkan Tanyıldızı, Fırat University

Assoc. Prof. Dr. Erol Kılıçkap, Dicle University

Assoc. Prof. Dr. Filiz Özgen, Fırat University

Assoc. Prof. Dr. Hakan Ateş, Gazi University

Assoc. Prof. Dr. Hülya Durmuş, Celal Bayar University

Assoc. Prof. Dr. İnanç Özgen, Fırat University

Assoc. Prof. Dr. Mehmet Ünsal, Sütçü İmam University

Assoc. Prof. Dr. Melik Çetin, Karabük, University

Assoc. Prof. Dr. Murat Yavuz Solmaz, Fırat University

Assoc. Prof. Dr. Oğuz Yakut, Fırat University

Assoc. Prof. Dr. Ömer Kaygılı, Fırat University

Assoc. Prof. Dr. Ömür Aydoğmuş, Fırat University

Assoc. Prof. Dr. Özlem Pelin Can, Cumhuriyet University

Assoc. Prof. Dr. Serkan Islak, Kastamonu University

Assoc. Prof. Dr. Tülay Yıldız, Fırat University

Assoc. Prof. Dr. Uğur Özsaraç, Sakarya University

Assoc. Prof. Dr. Yahya Hışman Çelik, Batman University

Assoc. Prof. Dr. Yüksel Esen, Fırat University

Asst. Prof. Dr. D. Koray Karabulut, Cumhuriyet University

Asst. Prof. Dr. Aydın Dikici, Fırat University

Asst. Prof. Dr. Ayça Gülten, Fırat University

Asst. Prof. Dr. D. Engin Alnak, Cumhuriyet University

Asst. Prof. Dr. Deepika Garg, GD Goenka University

Asst. Prof. Dr. Emre Turgut, Fırat University

Asst. Prof. Dr. Engin Ünal, Fırat University

Asst. Prof. Dr. Erkan Bahçe, İnönü University

Asst. Prof. Dr. Ferit Ak, Munzur University

Asst. Prof. Dr. Gonca Özmen Koca, Fırat University

Asst. Prof. Dr. İlker Temizer, Cumhuriyet University

Asst. Prof. Dr. İsmail Uzun, Süleyman Demirel University

Asst. Prof. Dr. Murat Karabatak, Fırat University

Asst. Prof. Dr. Müzeyyen Bulut Özek, Fırat University

Asst. Prof. Dr. Onur Özsolak, Cumhuriyet University

Asst. Prof. Dr. Şengül Doğan, Fırat University

Asst. Prof. Dr. Tahsin Yüksel, Cumhuriyet University

Asst. Prof. Dr. Yakup Say, Fırat University

ORGANIZATION COMMITTEE

Chairman of the Symposium

Prof. Dr. Niyazi Özdemir – Fırat University

Co-Chairman of the Symposium

Prof. Dr. Hikmet Esen – Fırat University

Secretary

Res. Asst. Abdullah Kapıcıoğlu

PhD. Student Fehmi Aslan

Layout Secretary

Res. Asst. Sercan Gülce Güngör Res. Asst. Cihangir Kale Res. Asst. Fatih Ünal

Members of the Committee

Prof. Dr. H. Serdar Yücesu, Gazi University

Prof. Dr. Z. Hakan Akpolat, Fırat University

Prof. Dr. Veli Çelik, Kırıkkale University

Prof. Dr. Messaoud Saidani, Coventry University

Prof. Dr. Galip Cansever, Yıldız Technical University

Prof. Dr. Tahir Khan, Bradford University

Prof. Dr. Abulfet Pelengov, Azerbaijan State Pedagogical University

Prof. Dr. Vasfi Hasırcı, Middle East Technical University

Prof. Dr. Kemal Leblebicioğlu, Middle East Technical University

Prof. Dr. Fahrettin Yakuphanoğlu, Fırat University

Prof. Dr. Niyazi Bulut, Fırat University

Prof. Dr. Hakan F. Öztop, Fırat University

Prof. Dr. Engin Avcı, Fırat University

Prof. Dr. Mehmet Eroğlu, Fırat University

Prof. Dr. Oğuzhan Keleştemur, Fırat University

Prof. Dr. Bahar Demirel, Fırat University

Prof. Dr. Ahmet Koca, Fırat University

Prof. Dr. Harun Tanyıldızı, Fırat University

Assoc. Prof. Dr. Ayhan Orhan, Fırat University

Assoc. Prof. Dr. Ulaş Çaydaş, Fırat University

Assoc. Prof. Dr. Resul Çöteli, Fırat University

Assoc. Prof. Dr. Muhammed Karaton, Fırat University

Assoc. Prof. Dr. Ibrahim Can, Cumhuriyet University

Assoc. Prof. Dr. Uğur Çalıgülü, Fırat University

Assoc. Prof. Dr. Ali Kaya Gür, Fırat University

Assoc. Prof. Dr. Asım Balbay, Siirt University

Assoc. Prof. Dr. Kadir Turan, Dicle University

Assoc. Prof. Dr. Murat Karabatak, Fırat University

Asst. Prof. Dr. Mustafa Ulaş, Fırat University

Asst. Prof. Dr. Salwa Boudila, Research and Technology Center of Energy

Asst. Prof. Dr. Yeşim Müge Şahin, Arel University

Asst. Prof. Dr. Göksel Durkaya, Atılım University

Asst. Prof. Dr. Gülüzar Tuna Keleştemur, Fırat University

Asst. Prof. Dr. Aytuğ Boyacı, Fırat University

Asst. Prof. Dr. Faruk Karaca, Fırat University

Asst. Prof. Dr. Serdar Mercan, Cumhuriyet University

Asst. Prof. Dr. Zülküf Balalan, Bingol University

Dr. Ebru Cavlak Aslan, Fırat University

Dr. Mert Gürtürk, Fırat University

Dr. Nida Katı, Fırat University

Nurettin Çek, Fırat University

Welcome to IATS 2017

It is a pleasure for us to offer you Full-Text Book for the 8th International Advanced

Technologies Symposium IATS’17. Our goal was to create a scientific platform that introduces

the newest results on internationally recognized experts to local students and colleagues and

simultaneously displays relevant Turkish achievements to the world. The positive feedback of

the community encouraged us to proceed and transform a single event into a symposium series.

Now, IATS’17 is honored by the presence of over 600 colleagues from various countries. We

stayed true to the original IATS’17 concept and accepted contributions from all fields of

innovative and advanced technologies to promote multidisciplinary discussions. The focal

points of the symposium emerged spontaneously from the submitted abstracts: energy

applications, advanced materials, electronic and optoelectronic devices. Our warmest thanks go

to all invited speakers, authors, and contributors of IATS’17 for accepting our invitation. We

hope that you will enjoy the symposium and look forward to meeting you again in one of the

forthcoming IATS’18 event.

Best regards,

Chairman of Symposium

Prof. Dr. Niyazi Özdemir

Chapter 9

523- EFFECT OF WIND SPEED ON OPTIMUM INSULATION THICKNESS FOR ENERGY SAVING IN ELAZIĞ (A.Gulten, F.S.Yavas)………………………………………………………………………………………………………………………………..1841

524- A COMPARATIVE STUDY FOR ENVIRONMENTAL EFFECT OF DIFFERENT INSULATION MATERIALS IN ELAZIĞ (A.Gulten, S. G. Armutlu)…………………………………………………………………………………………………………….. 1847

528- IMPROVEMENT OF FUSEL OIL FEATURES AND INVESTIGATION OF THE EFFECT OF A SPARK IGNITION ON A ENGINE PERFORMANCE AND EMISSIONS (S. Simsek, B. Özdalyan, H. Simsek)………………………………………… 1854

529- EFFECT OF QP PROCESS ON THE WEAR BEHAVIOUR OF AISI 4140 STEEL (F. Gul, E. Ersan)………………… 1866

531- VOLATILE MEMORY ANALYSIS TOOLS FOR VOIP FORENSIC APPLICATIONS: A CLASSIFICATION STUDY (H. Al-Saadawi, A. Varol)……………………………………………………………………………………………………………………… 1873

532- DESIGN OF FLAT SLEEPING BAG FOR SUMMER CAMPING (S. Kursun Bahadır, U.K. Sahin)…………………… 1881

533- THE EFFECT OF FILTERING ON IMAGE PROCESSING OF TEXTILE FABRICS (U.K. Sahin, S . Kurs un Bahadır)…………………………………………………………………………………………………………………………………. 1886

534- AN INVESTIGATION OF THE IMPACT OF BUILDING ORIENTATION ON COOLING LOAD CALCULATION (A. Yildiz, M. A. Ers oz, T. B. Bilki)………………………………………………………………………………………………………………… 1893

535- INFLUENCE OF TI AND B ADDITIONS ON MECHANICAL PROPERTIES OF 316 S TAINLESS STEEL (M. Cetin, T. Sunar)……………………………………………………………………………………………………………………………………..1901

537- PRODUCTION OF OPEN CELL ALUMINUM FOAM BY VACUUM CASTING METHOD (T. Sunar, M. Cetin)……… 1905

538- WEAR MECHANISMS OF WC–CO TOOL IN DRY MACHINING OF HEAT TREATED STEELS (Y.Ozcatalbas)…… 1910

539- THERMODYNAMIC ANALYSIS OF A GEOTHERMAL BASED TRIGENERATION SYSTEM (A. Ibrahim, H. Ozcan)…………………………………………………………………………………………………………………………………….1918

541- THREE DIMENSIONAL PRINTING TECHNOLOGY FOR S AND MOULD MAKING IN FOUNDRY (F. Gul, K. Aydin, A. Gok)……………………………………………………………………………………………………………………………………….1926

544- ROUTE PLANNING WITH ARTIFICIAL POTENTIAL FIELD METHOD IN AUTONOMOUS MOBILE ROBOTS (G. Gurguze, I. Turkoglu)…………………………………………………………………………………………………………………. 1935

545- VIDEO ANALYSIS OF MORRIS WATER MAZE EXPERIMENT (S. Yavuzkılıc, A. Sengur, Z. Cambay, İ. Emre )… 1941

546- THE DESIGN OF ANALOG MODULATION SIMULATOR (F. Vatans e ver, N. A. Yalc in, M. Salama)………………. 1947

547- EULER-LAGRANGE MODELLING AND PASSIVITY BASED CONTROL OF AC MOTORS (N. A.Yalc in, F. Vatans e ver)…………………………………………………………………………………………………………………………….. 1952

550- PRODUCTION OF ALUMINUM FOAM WITH TIH2 (A. Canakci, Ö.Y Keskin, S. Özkaya)…………………………….. 1956

551- FINDING OF MICROANEURYSMS FOR EARLY DETECTION OF DIABETIC RETINOPATHY BY IMAGE PROCESSING (V. Agaoglu , E. Tanyildizi)…………………………………………………………………………………………………………... 1959

552- PIPEWORK STRUCTURAL VIBRATION ANALYSIS AT PUMP STATION IN CRUDE OIL TRANSMISSION PIPELINES (A. Sahin, E. Ozdemir)………………………………………………………………………………………………………………… 1964

555- MICROSTRUCTURAL AND MECHANICAL CHARACTERIZATION OF DISSIMILAR METAL WELD BETWEEN HASTELLOY C-276 AND AISI 316L AUSTENITIC STAINLESS STEEL (M. Tumer, S . H. Atapek2, M. Z. Kerimak, F. Uluvar)…………………………………………………………………………………………………………………………………… 1972

556- COMPARISION OF SOFTWARE DEVELOPMENT PROCESS MODELS (G. Gurguze, R.Das, I. Turkoglu)………. 1979

557- EFFECT ON CUTTING FORCES OF MINIMUM QUANTITY LUBRICATION METHODS IN HARD TURNING OF 90MNCRV8 COLD WORK TOOL STEELS (N. Yilmaz, A. Öndas)……………………………………………………………… 1989

559- THE DESIGN OF WASTE ENERGY RECYCLING EXHAUST SYSTEM AND INVESTIGATION OF ITS EFFECTS ON THE ENGINE (İ. Temizer, T. Yuksel, İ. Can)……………………………………………………………………………………….. 1998

560- EXPERIMENTAL AND NUMERICAL ANALYSIS OF SEMICONDUCTORS USED IN AUTOMOTIVE THERMOELECTRIC SYSTEMS (İ.Temizer, C.İlkilic)……………………………………………………………………………………………………… 2006

562- EFFECT OF ADDING ELLIPSOIDAL HEIGHT OF POINTS IN ARTIFICIAL NEURAL NETWORK TO ESTIMATE GEOID HEIGHTS (M. Yilmaz, M. Ulukavak)…………………………………………………………………………………………….….. 2015

564- ESTIMATION OF GEOID HEIGHTS USING WITH/WITHOUT ELLIPSOIDAL HEIGHTS BY FUZZY LOGIC (M. Yilmaz, M. Ulukavak)…………………………………………………………………………………………………………………………… 2022

568- CRACK DEVELOPMENT ANALYSIS OF ENGINEERED CEMENTITIOUS COMPOSITES BY DIGITAL IMAGE CORRELATION UNDER BENDING (E. Godek, S. Okuyucu, T. Yildirim, M. Keskinates)…………………………………… 2028

569- CLASSIFICATION OF SATELLITE IMAGES BY DEEP LEARNİNG (F. Dogan, İ. Turkoglu)………………………….. 2036

571- OPTIMIZATION OF THE TRAFFIC LIGHTS BASED ON DENSITY OF VEHICLES (E. Ozturk, F. B. Gunay, T. Cavdar)………………………………………………………………………………………………………………………………..… 2044

572- NETWORK SLICING ON 5G MOBILE NETWORKS: A REVIEW, RESEARCH ISSUES AND CHALLENGES (M. T. Kakiz, E. Özturk, T. Cavdar)…………………………………………………………………………………………………………….…… 2049

Crack Development Analysis of Engineered Cementitious Composites by Digital Image Correlation Under Bending

Eren Gödek1 , Serdar Okuyucu2 ld r m3 3,

4 4

1Technical Sciences Vocational School, Hitit University, Çorum, Turkey2

3 The Graduate School of Natural and Applied Science, D4

AbstractEngineered Cementitious Composites (ECC) are special types of strain hardening cement based composites that exhibit multiple cracking behavior with limited crack widths under external loads. Determination of strain fields and detection of crack development are reasonably important topics which contribute to the evaluation of the mechanical performance of cement based materials under loads. Conventional measurement methods for the examination of local strains and crack formations (initiation and propagation) of cement-based materials have some constraints and drawbacks due to formation of multiple cracks in ECC.

In this study, digital image correlation (DIC) method was used for the investigation of crack development in ECC under bending. For this purpose, a 40x40x160mm prismatic ECC composite was prepared by using high tenacity poly-propylene fibers with a ratio of 2% of total volume. After 28 days of curing, mechanical performance of composite was investigated under three point bending. A DIC test setup has been placed in front of the speckled bending test specimen and images have been captured by 5 second intervals during the test. Images have been analyzed by using software of the DIC setup. Strain fields and propagation of multiple cracks were evaluated at every 0.5 mm of mid-point deflection of composite by using a MATLAB algorithm. In conclusion, DIC technique was found as a proper method for determination of crack widths at any deflection level as well as monitoring crack propagation and strain fields.

Keywords: Engineered Cementitious Composites (ECC), Digital Image Correlation (DIC), multiple cracks, crack development.

1. INTRODUCTION

The formation of cracks in cement-based composites is critical for maintaining the required strength and durability performance of the materials in their service life. In addition, the strain capacity of any material isterminated by crack formation. Therefore, analyzing the crack development of cement-based composites is vital for the determination of stress-strain relation of materials.

* Corresponding author. Tel.: +90-364-223 0800/3409E-mail address: [email protected] (E. Gödek).

2028

In many cement-based composites, materials lose its load carrying capacity suddenly after the formation of first crack at a limited deformation level with low toughness. In conventional fiber reinforced composites (FRC), the ability of the composite to carry the load can be controlled rather than a sudden drop and deformation capacity and the toughness of composite can also be increased. However, the most of the FRCs still show deformation softening behavior and their load carrying capacity cannot be increased. In 1990s, Engineered Cementitious Composites (ECC) are introduced to the literature by Prof. Dr. Victor Li and co-workers which are the special types of fiber reinforced cement based composites with an enhanced ductility as much as three hundred times that of normal concrete [1]. ECC, includes polymeric fibers by 2% of total composite volume and exhibit multiple micro-crack formation which result in pseudo deformation hardening behavior contrary to conventional FRCs. Therefore, not only the deformation capacity but also the load carrying capacity of ECC can be increased, greatly. It must be noted that in order to attain the multiple cracking and therefore pseudo deformation hardening behavior, micro-mechanical model criterions (strength criterion and the energy criterion) should be taken into account [2]. Some application areas of ECC are bridge decks to improve fatigue resistance, dampers in reinforced concrete buildings, repair material for deteriorated concrete surfaces [3].

Deformation measurement tools such as strain and clip gauges can be successfully used for obtaining the local strain, deformation and crack width values at fixing points of the conventional cement based composites due to one or fewer crack formation [4]. In ECC, such measurement tools may not be useful since several cracks are formed randomly throughout the specimen with limited crack widths. Therefore, development of a full-field strain mapping method at micro-meter scale resolution has become inevitable for monitoring the multiple cracking behavior of ECC. Digital Image Correlation (DIC) is a non-contact mathematic-based deformation measurement methodology. Recently, DIC method has been used for monitoring the crack development of cement based materials owing to its advantages such as non-contact, full-field measurement, simplicity in use and the continuous measurements up to failure [4]. Flexural cracking behaviors of various concrete beams were investigated by using DIC technique [4]. References [5] and [6] used DIC technique to measure specimen (FRC and ECC) deformations and to detect and quantify the formation of cracks, continuously. [7] used DIC for monitoring the crack development of strain hardening geopolymer composites under tensile loading and visualized the multiple cracking patterns by strain maps obtained from DIC analysis (Figure 1a). Also, the crack numbers and average crack widths of tensile specimens at specified strain values were calculated. They drew a virtual line to the center of the specimen and achieved strain data from this line (Figure 1b). Once the crack is opened, a sudden rise (peak) in the strain data is occurred and crack numbers can be obtained by counting the number of the peaks (Figure 1c). The area under the each peak represents the local deformation that caused by the crack formation and can be accepted as the width of the crack [7].

(a) (b) (c)

Figure 1. a) Visualized strain map, b) Area of interest and virtual line, c) Local strain values achieved from virtual line under tensile loading [7].

In this study, DIC method was used for the investigation of crack development in ECC under three point bending test. Propagation of multiple cracking behavior and local strain fields of ECC were visualized at every 0.5 mm of mid-point deflection of composite. Crack number, crack widths and crack width distribution of ECC were calculated in an automated manner by using DIC data and a Matlab algorithm developed for this purpose.

2. MATERIALS AND METHODS

2029

CEM I 42.5 R type ordinary Portland cement (OPC), ground granulated blast furnace slag (GGBFS), water and poly-carboxylate based high range water reducing admixture (HRWRA) were used for the matrix preparation of the ECC. Chemical and physical properties of Portland cement and granulated blast furnace slag were presented in Table I. used by 2% of total matrix volume. The density, nominal tensile strength, Young's modulus and elongation at rupture of HTPP fibers were 0.91 g/cm3, 850 MPa, 6 GPa, and 21%, respectively.

Table I. Chemical and physical properties of Portland cement and ground granulated blast furnace slag

SiO2Al2O

3

Fe2O3

CaO MgO Na2O

K2O SO3 Cl-

Specific

Gravity

Blaine (m2/kg

)

Retaining on 90

μm sieve (%)

Retaining on 45

μm sieve (%)

OPC 18.46 4.18 3.17 64.2

8 1.27 0.50 0.84 3.14

0.006 3.10 305 1.5 23.1

GGBFS

39.98 11.06 0.77 32.9

5 10.2

6 - - 0.34

0.007 2.87 550 0 0.4

Matrix phase with a water to cement ratio (W/C) of 1.10, water to binder ratio of 0.31 and powder materials to cement ratio of 2.5 was designed by weight. Mix proportions of ECC specimen was given in Table II. Powder ingredients were premixed without water for 2 min. Water and HRWRA were added and mixed for 3 min. HTPP fibers were then added to the mixture and mixed for another 5 min in order to ensure homogenous fiber dispersion to whole matrix. Matrix was also checked by hand if any balling of fibers present in fresh composites, and no fiber clumping was observed. Specimens were cast into 40x40x160 mm mold, demolded one day after casting and cured in water for 27 days.

Table II. Mix proportions of ECC specimen

Ingredients (kg/m3) OPC GGBFS Water HRWRA HTPP fibers

S 424 1059 466 8 18

A DIC system integrated three point bending test setup was used for investigating the flexural performance and crack development of specimen. Test setup was presented in Figure 2. In the DIC system, a CMOS camera with a resolution of 24.2 megapixels and two LED tripod lights were used. The camera was positioned to be perpendicular to the surface center of the specimen.

Three point bending test was performed to the specimen with a displacement rate of 0.5 mm/minute. The mid-span deflection of specimen was measured by use of a linear variable differential transformer. Load and deflection data were recorded by using the software of bending test setup. Load-deflection curves of the specimens were plotted by using these data and have been used for the determination of first cracking strength, flexural strength, deflection capacity and flexural toughness of specimens. As a common method for the detection of first cracking strength, first cracking load is taken as the load at which the load-deflection relationship becomes non-linear (load at the first drop on the curve). If there is a continuous slope change at the initial portion of the Flexural load–Mid-span deflection curve instead of a sudden load drop, two tangents are prolonged from the linear portions of the curve and the vertical intersection point is accepted as the first cracking load [8]. The maximum flexural load that achieved during the bending test is determined as the peak load. By using the first cracking load and the peak load, the first cracking and flexural strengths can be calculated by using the formula; = 1.5 × ××

(1)

-span length, b and h are the width and height of the specimen, respectively. The corresponding deflection value of the peak load is accepted as deflection capacity of thespecimen. In conventional deflection softening fiber reinforced cement based composites, toughness usually indicates the sum of the areas under the load-deflection curves. However, in ECC, another description is used

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for the determination of the toughness due to the deflection hardening behavior of composites. The total area under the load-deflection curve until peak load is named as “Peak Toughness”, and used for the determination of toughness value of each composite [9].

Before three point bending test, specimen was dried in air for one day and its surface to be examined with DIC was fully painted with white-color spray paint and left to dry completely. In order to generate the speckle pattern for DIC examinations, white surface was speckled with black-color spray paint and specimen dried for another one day. The bending experiment was started simultaneously with the DIC system and images were taken by 5 seconds intervals during the experiment. One of the specimens which resulted the best performance in terms of flexural strength and deflection capacity was examined by DIC within the scope of this paper. The crack development of this specimen was investigated in detail. DIC examinations of other specimens are still in progress.

Figure 2. DIC integrated three point bending test setup.

The images of the specimen were analyzed with Vic2D software. The area of interest (AOI) on the specimen was 35.6x100 mm. The resolution was 20.57 μm for per pixel. Subset and step size for DIC analysis were selected as 81x81 and 9 pixel, respectively. A virtual line was drawn to the tensile section of AOI of the specimen with the reason of this section was the region with the largest crack widths. Strain data were obtained from each image through this line and crack development analyses were performed by using a Matlab algorithm developed for this purpose. Crack numbers were determined by counting the peaks. The area under each peak was calculated and crack widths were obtained for each crack, individually. The average crack width was calculated by dividing the total area under the strain curve to total peak number. First, the usability of DIC for the detection of first cracking strength was investigated. After that, total crack number, average crack widthand crack width distributions were achieved for every 0.5 mm deflection level of specimen by using the sameMatlab algorithm.

3. RESULTS AND DISCUSSION

3.1. Flexural Performances of SpecimensFlexural performances of specimens under three point bending test were investigated. Flexural load–Mid-span deflection curves of specimens were given in Figure 3. First crack strength, flexural strength, deflection capacity and peak toughness values of specimens were calculated. Crack numbers of specimens were visually counted from the specimens. All results were presented in Table III.

All specimens exhibited multiple-cracking behavior under bending tests. The maximum flexural load and deflection capacity of specimens ranged between 9.79-11.98 MPa and 1.32-2.00 mm. The averages of first

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crack and flexural strengths of specimens were 4.58 and 10.83 MPa, respectively. An average deflection capacity of 1.59 mm was obtained and average peak toughness value was calculated as 1.26 J (Table III). S1 specimen showed the best performance in terms of flexural strength, deflection capacity and peak toughness. Due to this reason, images of the S1 specimen were used in DIC analysis within the scope of this study.

Figure 3. Flexural load–Mid-span deflection curves of specimens

Table III. Mix proportions of ECC specimen

Specimen First Crack Strength (MPa)

Flexural Strength (MPa)

Deflection Capacity (mm)

Peak Toughness (J)

Crack Number(Visually counted)

S1 4.57 11.98 2.00 1.69 9

S2 6.09 10.72 1.45 1.08 7

S3 3.09 9.79 1.32 1.00 10

Averages 4.58 10.83 1.59 1.26 8.7

3.2. Crack Development Analysis

3.2.1. Detection of First Cracking StrengthFlexural load–Mid-span deflection curve of the specimen (S1) was given in Figure 4 for the purpose of the first cracking load detection as mentioned in Section 2. First non-linearity encountered on the curve was between 1400-1600N as seen in Figure 4b. The first cracking load was then determined as approximately 1500N among the available data and first cracking strength is calculated as 4.57 MPa. However, it must be noted that in this method the determination of the first cracking strength can be regarded as an assumption since no visual demonstration can be made (the width of the crack is invisible to human eye).

(a) (b)

Figure 4. Detection of first cracking load in common method.

In DIC methodology (Figure 5), the number of image was determined when the first crack formation was observed (image 9, Figure 5a,b). The time elapsed from the start of the bending test was determined by counting the 5 second intervals between the capture of images (40 seconds). In flexural test setup, 10 data per second

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was recorded into an excel file. From the achieved data, first cracking load was read as 1491.52 N (400 data was recorded at 40 seconds; Figure 5c) and first cracking strength was calculated as 4.54 MPa.

(a) (b) (c)

Figure 5. Detection of first cracking load with DIC methodology; a) Image of the first crack, b) Detection of image number, c) Reading first cracking load from the achieved data.

When the results were taken into account, both DIC and common methodology gave similar first cracking strength values. Common methodology for the detection of first cracking load was verified with the DIC results not only with the calculation of strength value but also with the visual examination.

3.2.2. Crack Development Analysis of ECC specimen

Crack development analysis results of S1 specimen was presented in Figure 6 for each 0.5 mm deflection level.Flexural strength-Mid-span deflection curve, crack width distribution graph and local strain map were placed in the first, second and third columns of the Figure 6, respectively.

4 cracks were counted at 0.5 mm deflection level. While 2 of the cracks that formed were below 100 μm, the other two were between 100-200 μm. The average crack width of the specimen was calculated as 66.23 μm(Figure 6; 2nd row). When the deflection value was increased up to 1.0 mm, 3 additional cracks were formed and a total of 7 cracks were counted. Some of the crack widths were widen and ranged between 200-300 μm. The average crack width of the specimen was increased to 151.27 μm (Figure 6; 3rd row). When the deflection level reached to the 1.5 mm, crack number increased by 1 and counted as 8. The average crack width of the specimen was measured as 249.84 μm. Local strain values increased up to 0.5%. The minor and major crack widths were measured as 17.31 μm and 537.34 μm, respectively (Figure 6; 4th row). At the 2.0 mm deflection level, peak load was reached and the crack number stayed as 8. After that level of loading, one of the cracks started to widen significantly while the widths of the other cracks either stayed at the same value or decreased slightly. The average crack width increased to 342.75 μm and the minor and major crack widths were measured as 16.32 μm and 768.66 μm, respectively (Figure 6; 5th row). The significant increase in the local strain valuesat two of the cracks are the main reason of the increase in the average crack width. When the deflection increased to 2.5 mm, load carrying capacity of the specimen was decreased and the S1specimen started toexhibit deflection softening behavior (Figure 6; 6th row). One of the cracks at the middle of the specimen (where both the shear and moment forces are at their maximum) started to widen quickly and became major crack. Local strain value of the major crack and consequently the width of the crack were measured as high as 2.5% and 957.59 μm. The average crack width also increased to 451.20 μm. However, when the crack width histograms of S1 at 2.0 and 2.5 mm deflection values were taken into account, it can be said that the other cracks maintained their width steadily.

9th image

First crack

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Figure 6. Crack development analysis results of S1 specimen for each 0.5 mm mid-span deflection level.

Flexural Load – Mid-span Deflection Curve Crack Width Distribution Local Strain Map

0 mm

2.5 mm

2.0 mm

1.5 mm

1.0 mm

0.5 mm

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4. CONCLUSION

The flexural behavior and crack development of ECC was investigated in this study. ECC exhibited deflection hardening behavior under three point bending test until its ultimate load carrying capacity was reached. Formation of multiple cracks was observed. The first cracking strength of ECC was calculated by using DIC and the accuracy of common method was validated. DIC method was used for monitoring the crack formation of ECC during the bending test. Crack development analysis for every 0.5 mm mid-span deflection level was performed in an automatic manner by using the data that achieved from the DIC analysis and a Matlab algorithm. At each deflection stage; crack number, crack width and crack width distributions were also obtained by this methodology, successfully.

ACKNOWLEDGEMETFinancial support was provided by TUBITAK (The Scientific and Technological Research Council of Turkey) under the Grant No. 115R012 Adana cement (Ground granulated blast furnace slag), Grace Company (HRWRA) and Saint-Gobain Brasil (HTPP fiber) are gratefully acknowledged.

REFERENCES

[1] Li, V. C., From micromechanics to structural engineering - the design of cementitious composites for civil engineering applications. Doboku Gakkai Rombun-Hokokushu/Proceedings of the Japan Society of Civil Engineers, (471 pt 1-24); 1-12, 1993.

[2] Li V. C., Engineered Cementitious Composites (ECC) – Tailored composites through micromechanical modeling, Fibre reinforced concrete: Present and the future. In: Banthia N, Mufti A, (eds.), Canadian Society of Civil Engineers, 64–97, 1998.

[3] Kunieda, M., Rokugo, K., Recent progress on HPFRCC in Japan. Journal of Advanced Concrete Technology, 4(1); 19-33, 2006.

[4] Hamrat, M., Boulekbache, B., Chemrouk, M., Amziane, S. Flexural cracking behavior of normal strength, high strength and high strength fiber concrete beams, using Digital Image Correlation technique. Construction and Building Materials,106; 678-692, 2016.

[5] Finazzi, S., Paegle, I., Fischer, G., Minelli, F. Influence of bending test configuration on cracking behavior of FRC. In 3rd All-Russia (International) Conference on Concrete and Reinforced Concrete, Chicago, p.196-205, 2014.

[6] Paegle, I., Minelli, F., Fischer, G. Cracking and load-deformation behavior of fiber reinforced concrete: Influence of testing method. Cement and Concrete Composites, 73; 147-163, 2016.

[7] Ohno, M., Li, V. C., A feasibility study of strain hardening fiber reinforced fly ash-based geopolymer composites. Construction and Building Materials, 57; 163-168, 2014.

[8] Tosun-Felekoglu, K., Felekoglu, B. Effects of fibre hybridization on multiple cracking potential of cement-based composites under flexural loading. Construction and Building Materials, 41; 15-20, 2013.

[9] Park, S. H., Kim, D. J., Kim, S. W. Investigating the impact resistance of ultra-high-performance fiber-reinforced concrete using an improved strain energy impact test machine. Construction and Building Materials, 125; 145-159, 2016.

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