INVESTIGATIONS ON THE GLASS FIBER CONCRETE REINFORCEMENT WITH SrO-Mn 2 O 3 -Fe 2 O 3 -MgO- ZrO 2 -SiO 2 (SMFMZS) SYSTEM GLASS FIBERS

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1 INVESTIGATIONS ON THE GLASS FIBER CONCRETE REINFORCEMENT WITH SrO-Mn 2 O 3 -Fe 2 O 3 -MgO- ZrO 2 -SiO 2 (SMFMZS) SYSTEM GLASS FIBERS Prof. Dr. Bekir KARASU Anadolu University, Department of Materials Science and Engineering, Eskişehir/TÜRKİYE

2 It is a versatile material that can easily be mixed with some other suitable components to meet a variety of special needs and to form virtually to any shape. What is Concrete? Concrete is one of the most commonly used building materials. It is a composite material made from several readily available constituents. (such as aggregates, sand, cement, water).

3 What is Glass Fiber Reinforced Concrete (GFRC)? GLASS

4 Reinforcing Mechanism The reinforcement (with glass fiber for example) in an alkali resistant (RC) structure has to undergo the same strain or deformation as the surrounding concrete in order to prevent discontinuity, slip or separation of the two materials under load. Maintaining composite action requires load transfer between concrete and fiber. The direct stress is transferred from the concrete to fiber interface so as to change the tensile stress in the reinforcing fiber along its length. This load transfer is achieved by means of bond (anchorage) and is idealized as a continuous stress field that develops in the vicinity of the fiber-concrete interface.

5 Traditional Concrete Load Resistance Tensile Stress Compressive Stress

6 Reinforcing Mechanism

7 Why is the Corrosion Behaviour of Glasses So Important? When used as an additive in the cement, it is very clear that glass is influenced by alkaline medium. How does the interaction level vary depending on glass composition?

8 Alkali Resistant (AR) Glass Fibers In the 1970s alkali-resistant (AR) glass fibers were perfected by Owens- Corning and by Nippon Electric Glass (NEG) leading to a rapid increase in their applications.

9 Importance of Alkali Resistance of Glass Fiber There is a reaction of amorphous silica (chalcedony, chert, siliceous limestone) sometimes present in the aggregates with the hydroxyl ions (OH - ) from the cement solution. Poorly crystallized silica (SiO 2 ) dissolves and dissociates at high ph ( ) of alkali environment. The alkali-silica reaction causes localised swelling being responsible of tensile stress and cracking.

10 SrO-MgO-ZrO 2 -SiO 2 (SMZS) System Glasses It has mentioned in previously done studies that the suitable SMZS glass composition is 26 SrO, 20 MgO, 14 ZrO 2 and 40 SiO 2 (in wt. %). Chemical resistance arises due to high amount of zirconia, strontia and magnesia contents in the chemical composition.

11 Experimental Procedure of Chemical Resistance of Glass Fiber 40 g NaOH pure water (1 M NaOH ) 250 ml plastic containers suspended in the solution (cut in 5 cm length) into water boat (75 o C)

12 The Chemical Resistance Test Results of Commercial Glass Fibers and Studied Frits

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15 Experimental Procedure of Fe11 Glass Belonging to SrO- Mn 2 O 3 -Fe 2 O 3 -MgO-ZrO 2 -SiO 2 (SMFMZS) System Batch Preparation (in platinum crucible) Calcination (900 C) Glass Melting (1550 C 6h 45 min.)

16 The results clearly presented that this compound is not convenient for fiber drawing due to intense crystal phase formations evolved nearly in all the bulk glass. It was determined that the formed crystals which were Mg- and Zr-aluminosilicates through the bulk Fe11 glass severely disrupted the fluidity of glass melt, causing discontinuity in fiber drawing. Therefore, it was decided that the composition of Fe11 must be tailored in terms of suitable viscosity which will not allow undesired crystallization for a successful fiber drawl.

17 Temperature C Glass samples were specially placed in MSE-GF-1300 model horizontal gradient furnace. The temperature was increased up to 1100 C. FOR THE Fe11 GLASS TEMPERATURE Step No The data acquired from the gradient furnace for Fe11 glass.

18 Heat Treated Fe11 Sample The SEM image of the sample at step no 1.

19 Heat Treated Fe11 Sample The SEM image of the sample at step no 13.

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21 (a) The SEM image of Fe11 glass stuck edge of the platinum rod after fiber glass drawing process, (b-d) EDX analysis results of numbered regions. b c 3 2 d

22 Fiber Production Attempts with SMFMZS System Glasses Because of the problem caused by Fe11 composition, Zrn1 glass fiber composition was fixed. MgO has a crystallisation suppressing effect when added into chemical composition up to a certain level. So, being sure of the fact that the studied composition has sufficient MgO content some amount of soda-lime-silica glass was added to the batch.

23 Glass Production Flow Chart for Zrn1 Batch Preparation Calcination 900 o C, 2h. Glass Melting 1550 ºC, 6 hr 45 min. Fiber Drawing 1460 ºC, 6 C/ min. Annealing 750 ºC, 2 h. Chemical Durability Test 1M NaOH water bath at 75 ºC Characterisation SEM, XRD and etc.

24 A glass melt derived from Zrn1 batch in the platinum crucible.

25 The SEM-SE Image of Zrn1 Glass Fiber Zrn1 glass fiber has approx. 160 µm wideness.

26 The Chemical Resistance Test Results of Zrn1 Glass Fibers Comparing with Different Components

27 Şiddet (cps) XRD analysis curve acquired from the gradient furnace sample which corresponds to 1. step Kırınım Açısı (2 Teta) The data acquired from the gradient furnace for Zrn1 glass.

28 The SEM-EDX Analysis for Zrn1 Glass Heat Treated in the Gradient Furnace

29 Traditional Concrete Preparation Silicate sand + Cement + Agregates + (Polymer Adva Flow 501) + Water + Additives Mixing Water/Concrete: 0.5 Fiber Addition Moulding

30 Concrete Structure Reinforced with Zrn1 Fibers The SEM images derived from Zrn1 fiber in the concrete. Red signs inhibit that Zrn1 fibers behave like crack absorbing agent.

31 SEM Images Exhibiting that Homogenous Connection of Zrn1 Fiber in the Concrete

32 Mechanical Test of Zrn1 Fiber Reinforced Concrete 3 pieces of each sample were prepared and then treated (cured) for 2 (48 h), 7 (164 h) and 28 days (672 h) in water. Portland cement (42.5) was used to prepare concrete specimens. Endurance tests were carried out by an uniaxial compressive strength device. Ultimate strength=compressive strength (kgf)/surface area (cm 2 ).

33 Obtained Compressive Strength Values of the Samples Samples Compressive Strength (MPa) 2 days Compressive Strength (MPa) 7 days Compressive Strength (MPa) 28 days Standard 2, Glass fiber %1 Glass fiber %3 Glass fiber %5 Glass fiber %

34 Thank You for Your Valuable Attention! Arslan, G., Karasu, B., Dolekcekic, E., Kaya, G. and Gunkaya, G., Effect of Transition Metal Oxide Additions on the Chemical Durability of SrO MgO ZrO 2 SiO 2 Glasses, Glass Technology: The European Journal of Glass Science & Technology Part A, Vol. 50, No. 1, 17 24, Yurdakul, A., Günkaya, G., Dölekçekiç, E., Kavas, T., Karasu, B., Novel Glass Compositions for Fiber Drawing, Ceramic International, Vol. 41, Issue 10, Part A, , Yurdakul, A., Dolekcekic, E., Gunkaya, G., Kavas, T., Karasu, B., Usage of High Alkali Resistance SrO Mn 2 O 3 Fe 2 O 3 MgO ZrO 2 SiO 2 (SMFMZS) System Glass Fibers in Cement Structure and Their Characterization, Construction & Building Materials, 2017 (in press).

35 INVESTIGATIONS ON THE GLASS FIBER CONCRETE REINFORCEMENT WITH SrO-Mn 2 O 3 -Fe 2 O 3 -MgO- ZrO 2 -SiO 2 (SMFMZS) SYSTEM GLASS FIBERS Prof. Dr. Bekir KARASU Anadolu University, Department of Materials Science and Engineering, Eskişehir/TÜRKİYE