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Sensitivity of Optical Fiber Sensors to Deflection of Reinforced Concrete Beam

Sensitivity of Optical Fiber Sensors to Deflection of Reinforced Concrete Beam ICETIR 2020 IOP Publishing IOP Conf. Series: Materials Science and Engineering 982 (2020) 012025 doi:10.1088/1757-899X/982/1/012025 Sensitivity of Optical Fiber Sensors to Deflection of Reinforced Concrete Beam 1,3 1 2 Farida Asriani . Winasis and Gandjar Pamudji Electrical Engineering Departement. Universitas Jenderal Soedirman Civil Engineering Departement. Universitas Jenderal Soedirman [email protected] Abstract. The capacity of concrete beams will decrease by many external factors. To find simple and reliable method to monitor the quality of concrete beams is a challenging task. An optical-based fiber sensors is very interesting to develop for such task because of its many advantages. In this study, the optical fiber sensors were embedded in reinforced concrete beams to detect and to monitor deflection of the beam where a straight-line configuration of optical fiber was used. We perform experimental work to test performance of the use of optical fiber sensor by collecting data from flexural testing the concrete beam with the Universal Testing Machine (UTM). While the concrete deflection was measured by (linear variable differtial transducer (LVDT) as elongation unit, the fiber optic sensor output was observed in volts unit. We test the sensitivity of the optical fiber sensor by analyzing the relationship graph between the changes in the deflection of the concrete beam and output voltage of optical fiber sensors. The results show that optical fiber sensors have good sensitivity to detect and monitor concrete beam deflection. 1. Introduction Sensors are a major component in the development of a monitoring system. At present, research on the use of fiber optic sensors (FOS) is being developed. The advantage of this FOS is better resistance to electromagnetic interference. including storms. and the potential ability to live in a harsh environment. FOS is also resistant to corrosion when used. in open structures (such as bridges and dams) that can be used throughout the lifetime of concrete. Fiber optic sensors that are widely applied include micro bending sensors. wave sensor. FBGs. and fiber optics interferometer [1]. Fiber optic sensors provide a good response to loads applied to concrete with embedded fiber optic sensors. Changes in load indicate changes in the intensity of light that is passed on the optical fiber sensor[2].Optical fiber sensors embedded in lightweight concrete have been applied to detect damage or cracks in concrete. Measurements were made using an optical power meter. The experimental results show that when cracks occur in concrete there is a significant decrease in the output of fiber optic sensors [3]. The use of optical fiber sensors in monitoring concrete structures has been developed previously. Detection concrete collapse by monitoring the concrete strain has been carried out. In this study, fiber optic sensors are coated with chemical material[4][5]. Lightweight concrete damage detection with Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Published under licence by IOP Publishing Ltd 1 ICETIR 2020 IOP Publishing IOP Conf. Series: Materials Science and Engineering 982 (2020) 012025 doi:10.1088/1757-899X/982/1/012025 optical fiber sensors with other methods was develop. When the quality of concrete decreases, the optical fiber sensor output power also decreases [6]. In a reinforced concrete beam monitoring system, the compressive strength, strain, and deflection parameters are the main parameters monitored. Single mode type optical fiber has been applied to detect strain in lightweight concrete. The value of power loss generated by optical fiber due to loading is directly proportional to the value of the load given. The test results show that optical fiber with A wave configuration has good sensitivity to changes in load given to concrete.[7]. Distributed optical fiber sensors have also been applied to measure strain on reinforced concrete wall reinforcement [8]. Measurement of reinforced concrete beam deflection has been carried out in the laboratory, so there are many problems if direct measurements will be applied for the purposes of continuous monitoring of reinforced concrete structures. For this reason, it is necessary to develop a sensor system embedded in concrete. In this paper, the sensitivity of fiber optic sensor sensitivity to the deflection parameters of reinforced concrete beams will be examined. 2. Experimental Method The sensitivity of the fiber optic sensor to reinforced concrete beam deflection is determined by taking data about the concrete deflection and the optical fiber sensor output power. To achieve this, the outline is divided into 3 steps, namely the design of fiber optic sensors. making reinforced concrete beam samples with embedded sensors and data acquisition and analysis. 2.1. Design of Fiber Optic Sensor Configuration The optical fiber sensors used in this study is single mode with a length of 4 meters. The configuration applied is a straight line as shown in Figure 1. optical fiber sensors are implanted straight in the beam. Figure 1. Stright line configuration of optical fiber The optical fiber sensor consists of two terminals. the input terminal that conected to laser source 1310nm. and the output terminal connected to the photodetector to convert the signal from the laser wave to the voltage level. The middle part of the fiber optic sensor is peeled off the jacket and the peeled part is installed embedded in a concrete beam. 2.2. Design of Reinforced Concrete Beams with an Embedded Sensor Concrete beams used in this study are lightweight reinforced concrete beams with 20MPa compressive strength. In order to reach a lightweight, plastic gravel is used [9] The size of the concrete blocks made is 8x16x160 cm. Fiber optic sensors are implanted in concrete with the straight configuration in Figure 2. The mix design of concrete is shown in Table 1. ICETIR 2020 IOP Publishing IOP Conf. Series: Materials Science and Engineering 982 (2020) 012025 doi:10.1088/1757-899X/982/1/012025 Figure 2. Model of concrete beam samples with embedded sensors Table 1. The mix design of concrete. Concrete Volume (Kg) - Plastic materials 1 M3 2*Sil 10/20 & * 1Sil 15/30 Cement 500 17,14 sand 845 28,96 Naturak gravel 0 0 Plastic gravel 432 14,8 SP Sika LN 12 0,4 water 150 5,14 2.3. Data Acquisition and Analysis Data acquisition is done by flexural testing using UTM. Concrete deflection is measured using LVDT. The observed data are changes in concrete deflection and changes in the optical fiber sensor output voltage due to loading on the concrete beam. The data acquisition scheme is shown in Figure 3. ICETIR 2020 IOP Publishing IOP Conf. Series: Materials Science and Engineering 982 (2020) 012025 doi:10.1088/1757-899X/982/1/012025 Figure 3. Data retrieval scheme 3. Result and Discussion 3.1. Data The fiber optic configuration in the concrete is shown in Figure 4, and the reinforced concrete block with embedded sensors is shown in Figure 5. Figure 4. fiber optic configuration inside the concrete mold Figure 5. Flexural testing concrate beam sample with embedded fiber optic In this study data were taken from 3 concrete beam samples with embedded sensors. The results of the data from the first concrete beam are shown in Table 2. The second concrete beam in Table 3 and the third concrete beam in Table 4. Tabel 2. The first concrete beam sample data ICETIR 2020 IOP Publishing IOP Conf. Series: Materials Science and Engineering 982 (2020) 012025 doi:10.1088/1757-899X/982/1/012025 Output voltage no load (kN) deflection (mm) optical fiber sensors (volt) 1 0.004941041 0.00000487 0.37 2 0.11957637 0.22377928 0.56 3 0.57090282 0.32311198 1.12 4 1.7325027 0.83081281 1.49 5 3.65113 1.196736 1.68 6 6.0351171 1.8259418 2.43 7 8.5939245 2.5912743 2.61 8 10.107606 3.0649996 3.17 9 14.518381 4.418685 3.55 10 16.03191 5.8213181 3.73 11 16.907057 8.036375 3.92 12 17.398458 9.9108582 4.11 13 17.840471 13.267413 4.48 Tabel 3. Second concrete beam sample data Output voltage no load (kN) deflection (mm) optical fiber sensors (volt) 1 0.068897821 0.036128148 0.4 2 0.51017541 0.52297401 0.6 3 1.1495951 0.72594935 0.81 4 2.6247454 1.1949829 1.01 5 3.5582852 1.4596689 1.41 6 5.3155766 2.051162 1.81 7 7.4279442 2.8705878 2.01 8 9.6917734 3.6616268 2.21 9 10.854418 4.0441976 2.62 10 13.480095 4.8764434 2.82 11 15.15642 5.4440699 3.02 12 15.846836 6.1979642 3.22 ICETIR 2020 IOP Publishing IOP Conf. Series: Materials Science and Engineering 982 (2020) 012025 doi:10.1088/1757-899X/982/1/012025 13 16.391153 6.8814449 3.62 14 16.709873 7.5666599 3.82 15 17.527981 12.060499 4.23 16 17.753162 22.424404 4.43 17 18.186796 38.390656 4.83 Tabel 4. Third concrete beam sample data Output voltage no load (kN) deflection (mm) optical fiber sensors (volt) 1 0.82641274 0.036763895 0.35 2 2.0133584 0.21275349 0.53 3 3.6153882 0.54891306 1.06 4 5.2496629 0.95169693 1.24 5 7.0092497 1.5461302 1.42 6 8.5411425 2.0465524 1.77 7 9.6772785 2.417012 1.95 8 11.71697 3.1238008 2.13 9 13.75316 3.8872695 2.3 10 14.499065 4.8545823 2.66 11 14.689847 6.7961712 3.19 12 15.386856 8.257062 3.54 13 16.247229 12.41567 4.08 14 16.62388 27.62908 4.25 15 17.472326 55.628048 4.61 Based on the test results with UTM, we obtain that the reinforced concrete beam has a maximum average load capacity of 17,833kN. While the mean deflection of reinforced concrete beams when loading is 35.62 mm. The average sensor output voltage when the concrete beam reaches its maximum capacity reaches the average of 4.64volt. From table 1, table 2 and table 3 it can be seen that both deflection and sensor output voltage increases with increasing loading test ICETIR 2020 IOP Publishing IOP Conf. Series: Materials Science and Engineering 982 (2020) 012025 doi:10.1088/1757-899X/982/1/012025 3.2. Sensitivity Analysis of Optical Fiber Sensors Sensitivity analysis is done by graphing the relationship between the deflection of the concrete beam and the optical fiber sensors output voltage. To determine the sensitivity, a linear region determined from the response of the fiber optic sensor, then a linear approach analysis is performed. 3.2.1. Embeded Sensor 1. Embedded sensor 1, is an optical fiber sensors that is embedded in the second concrete beam. The graph results for Embedded sensor 1 are shown in Figure 6. Embeded sensor 1 4,5 3,5 2,5 1,5 0,5 0 2 4 6 8 10 12 14 Deflection (mm) Figure 6. Graph of the relationship between the deflection of a concrete beam and the optical fiber sensor output voltage from first sensor. In Figure 6 can be seen that there are two different linear regions. This shows that the senor has different sensitivity values for two different linear regions. Graph linear 1a where the deflection value is less than 5 mm. The linear region 1b where the deflection value is more than the same as 5 mm. The results of the linear approach are shown in Figure 7 and Figure 8 Linear 1a 4,5 3,5 2,5 y = 0,7253x + 0,7201 R² = 0,9374 1,5 0,5 0 1 2 3 4 5 Deflection (mm) output voltage of fiber optic sensor output voltage of fiber optic sensor volt volt ICETIR 2020 IOP Publishing IOP Conf. Series: Materials Science and Engineering 982 (2020) 012025 doi:10.1088/1757-899X/982/1/012025 Figure 7. Linear approach 1a In the linear region 1a in the deflection range below 5mm, the optical fiber sensor has a sensitivity of 0.7253volt / mm. Linear 1b 4,5 3,5 y = 0,1014x + 3,1213 R² = 0,9966 2,5 1,5 0,5 0 2 4 6 8 10 12 14 Deflection (mm) Figure 8. Linear approach 1b In the linear region 1b, where the deflection range is more than or equal to 5mm, the fiber optic sensor has a sensitivity of 0.1014volt / mm. For embedded sensor 1, the sensitivity ratio of linear region 1a to linear region 1b reaches 7.15: 1 3.2.2. .Embedded Sensor 2. Embedded sensor 2, is an optical fiber sensor that is embedded in the second concrete beam. The graph results for Embedded sensor 2 are shown in Figure 9. Embeded sensor 2 0 5 10 15 20 25 30 35 40 45 Deflection (mm) output voltage of fiber optic sensor output voltage of fiber optic sensor volt volt ICETIR 2020 IOP Publishing IOP Conf. Series: Materials Science and Engineering 982 (2020) 012025 doi:10.1088/1757-899X/982/1/012025 Figure 9. Graph of the relationship between the deflection of a concrete beam and the optical fiber sensor output voltage from second sensor. In Figure 9, there are two linear region. Liear 2a show in Figure 10 and linear 2 b show in Figure Linear 2a 3,5 2,5 y = 0,4585x + 0,5566 R² = 0,9763 1,5 0,5 0 1 2 3 4 5 6 7 8 Deflection (mm) Figure 10. Linear approach 2a In the deflection range of concrete beams less than 8mm, optical fiber sensors embedded in concrete have a sensitivity of 0.4585volt / mm. Linear 2b 4,9 4,8 4,7 4,6 4,5 y = 0,023x + 3,9385 4,4 R² = 0,9954 4,3 4,2 4,1 0 5 10 15 20 25 30 35 40 45 Deflection (mm) Figure 11. Linear approach 2b output voltage of fiber optic sensor output voltage of fiber optic sensor volt volt ICETIR 2020 IOP Publishing IOP Conf. Series: Materials Science and Engineering 982 (2020) 012025 doi:10.1088/1757-899X/982/1/012025 In the deflection range of concrete beam more than the same as 8mm, optical fiber sensors embedded in concrete have a sensitivity of 0.023volt / mm. The ratio of linear sensitivity 2a to linear 2b is 19.93: 1 3.2.3. Embeded Sensor 3. The Embedded sensor 3 is an optical fiber sensors that embedded in the third concrete beam. The graph results for Embedded sensor 3 are shown in Figure 12. Embeded Sensor 3 0 10 20 30 40 50 60 Deflection (mm) Figure 12. Graph of the relationship between the deflection of a concrete beam and the optical fiber sensor output voltage from third sensor. Figure 12 shows the existence of two linear regions. The linear region in the deflection range is less than 9 mm, referred as the linear region 3a shown in Figure 13, and the linear region in the deflection range is greater than 9mm called the linear region 3b shown in Figure 14. Linear 3a 3,5 2,5 y = 0,3652x + 0,7895 1,5 R² = 0,9439 0,5 0 1 2 3 4 5 6 7 8 9 Deflection (mm) Figure 13. Linear approach 3a output voltage of fiber optic sensor output voltage of fiber optic sensor volt volt ICETIR 2020 IOP Publishing IOP Conf. Series: Materials Science and Engineering 982 (2020) 012025 doi:10.1088/1757-899X/982/1/012025 In the deflection range of less than 9mm, the fiber optic sensor has a sensitivity of 0.3652 volts / mm. Linear 3b 4,7 y = 0,0123x + 3,9198 4,6 R² = 0,9988 4,5 4,4 4,3 4,2 4,1 0 10 20 30 40 50 60 Deflection (mm) Figure 14. linear approch 3b In the deflection range above 9 mm, the optical fiber sensors have a sensitivity of 0.0123volt / mm. The sensitivity ratio of 3a to 3b is 29.69: 1. Based on data retrieval from the three sensors, it can be seen that the sensor has a good sensitivity in the linear a region with an average sensitivity of (0.7253volt / mm + 0.4585volt / mm + 0.3652 volts / mm) / 3 = 0.5613volt / mm. The average of effective working area is for deflection value less than 7.33mm 4. Conclusion Optical fiber sensor embedded with a straight configuration in concrete has a sensitivity related to the changes of reinforced concrete beam deflection in the number of 0.5613volt / mm and the average of effective working area is for deflection value less than 7.33mm References th [1] K. Fidanboylu and Efendioglu, H.S., “Fiber Optic Sensors and Their Applications,” 5 International Advanced Symposium (IATS'09). May, 2009. [2] S. Ahmad, M. U. Rizvi, S. Mohd, A. Husain, and A. Anwar, “Study of Fiber Optic Sensor Using Concrete Beams,” pp. 2319–2322, 2014. [3] Asriani Farida, Pamudji Gandjar, and Susilawati, H. “Pengembangan Deteksi Kerusakan Beton yang Menggunakan Agregat Sampah Plastik Dengan Sensor Fiber Optik Multi Mode Tertanam,” in Seminar Nasional Ketekniksipilan Bidang Vikasional III, 2016. [4] C. G. Berrocal, I. Fernandez, and R. Rempling, “Crack monitoring in reinforced concrete output voltage of fiber optic sensor volt ICETIR 2020 IOP Publishing IOP Conf. Series: Materials Science and Engineering 982 (2020) 012025 doi:10.1088/1757-899X/982/1/012025 beams by distributed optical fiber sensors,” Struct. Infrastruct. Eng., vol. 0, no. 0, pp. 1–16, [5] Barrias A, Casas Joan R, andVillalba S, “Embedded Distributed Optical Fiber Sensors in Reinforced Concrete Structure,” Sensors pp. 1–22, 2018. [6] F. Asriani, G. Pamudji, H. Susilawati, and S. W. Ismani, “Damage Detection Tool Design of Lightweight Concrete Using Optical Fiber Sensor and Phototransistor,” Ijitee, vol. 1, no. 1, pp. 8–12, 2017. [7] Asriani Farida, Pamudji Gandjar, and Susilawati Hesti, “Fiber Optik Singlemode Sebagai Sensor Regangan yang Tertanam di dalam Beton,” in Seminar Nasional Teknologi Terapan 2016, 2016. [8] J. E. Woods, D. T. Lau, X. Bao, and W. Li, “Measuring strain fields in FRP strengthened RC shear walls using a distributed fiber optic sensor,” vol. 152, pp. 359–369, 2017. [9] H. Purnomo, G. Pamudji, and M. Satim, “Influence of uncoated and coated plastic waste coarse aggregates to concrete compressive strength,” MATEC Web Conf., vol. 101, 2017. [10] P. Gandjar, H. Bimasena, P. A. Yuta, and P. Heru, “Bond-Slip Behavior of Steel Bar Embedded in Lightweight Concrete Using Sand Coated Polypropylene Coarse Aggregate,” Mater. Sci. Forum, vol. 929, pp. 103–108, 2018. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png IOP Conference Series Materials Science and Engineering IOP Publishing

Sensitivity of Optical Fiber Sensors to Deflection of Reinforced Concrete Beam

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ICETIR 2020 IOP Publishing IOP Conf. Series: Materials Science and Engineering 982 (2020) 012025 doi:10.1088/1757-899X/982/1/012025 Sensitivity of Optical Fiber Sensors to Deflection of Reinforced Concrete Beam 1,3 1 2 Farida Asriani . Winasis and Gandjar Pamudji Electrical Engineering Departement. Universitas Jenderal Soedirman Civil Engineering Departement. Universitas Jenderal Soedirman [email protected] Abstract. The capacity of concrete beams will decrease by many external factors. To find simple and reliable method to monitor the quality of concrete beams is a challenging task. An optical-based fiber sensors is very interesting to develop for such task because of its many advantages. In this study, the optical fiber sensors were embedded in reinforced concrete beams to detect and to monitor deflection of the beam where a straight-line configuration of optical fiber was used. We perform experimental work to test performance of the use of optical fiber sensor by collecting data from flexural testing the concrete beam with the Universal Testing Machine (UTM). While the concrete deflection was measured by (linear variable differtial transducer (LVDT) as elongation unit, the fiber optic sensor output was observed in volts unit. We test the sensitivity of the optical fiber sensor by analyzing the relationship graph between the changes in the deflection of the concrete beam and output voltage of optical fiber sensors. The results show that optical fiber sensors have good sensitivity to detect and monitor concrete beam deflection. 1. Introduction Sensors are a major component in the development of a monitoring system. At present, research on the use of fiber optic sensors (FOS) is being developed. The advantage of this FOS is better resistance to electromagnetic interference. including storms. and the potential ability to live in a harsh environment. FOS is also resistant to corrosion when used. in open structures (such as bridges and dams) that can be used throughout the lifetime of concrete. Fiber optic sensors that are widely applied include micro bending sensors. wave sensor. FBGs. and fiber optics interferometer [1]. Fiber optic sensors provide a good response to loads applied to concrete with embedded fiber optic sensors. Changes in load indicate changes in the intensity of light that is passed on the optical fiber sensor[2].Optical fiber sensors embedded in lightweight concrete have been applied to detect damage or cracks in concrete. Measurements were made using an optical power meter. The experimental results show that when cracks occur in concrete there is a significant decrease in the output of fiber optic sensors [3]. The use of optical fiber sensors in monitoring concrete structures has been developed previously. Detection concrete collapse by monitoring the concrete strain has been carried out. In this study, fiber optic sensors are coated with chemical material[4][5]. Lightweight concrete damage detection with Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Published under licence by IOP Publishing Ltd 1 ICETIR 2020 IOP Publishing IOP Conf. Series: Materials Science and Engineering 982 (2020) 012025 doi:10.1088/1757-899X/982/1/012025 optical fiber sensors with other methods was develop. When the quality of concrete decreases, the optical fiber sensor output power also decreases [6]. In a reinforced concrete beam monitoring system, the compressive strength, strain, and deflection parameters are the main parameters monitored. Single mode type optical fiber has been applied to detect strain in lightweight concrete. The value of power loss generated by optical fiber due to loading is directly proportional to the value of the load given. The test results show that optical fiber with A wave configuration has good sensitivity to changes in load given to concrete.[7]. Distributed optical fiber sensors have also been applied to measure strain on reinforced concrete wall reinforcement [8]. Measurement of reinforced concrete beam deflection has been carried out in the laboratory, so there are many problems if direct measurements will be applied for the purposes of continuous monitoring of reinforced concrete structures. For this reason, it is necessary to develop a sensor system embedded in concrete. In this paper, the sensitivity of fiber optic sensor sensitivity to the deflection parameters of reinforced concrete beams will be examined. 2. Experimental Method The sensitivity of the fiber optic sensor to reinforced concrete beam deflection is determined by taking data about the concrete deflection and the optical fiber sensor output power. To achieve this, the outline is divided into 3 steps, namely the design of fiber optic sensors. making reinforced concrete beam samples with embedded sensors and data acquisition and analysis. 2.1. Design of Fiber Optic Sensor Configuration The optical fiber sensors used in this study is single mode with a length of 4 meters. The configuration applied is a straight line as shown in Figure 1. optical fiber sensors are implanted straight in the beam. Figure 1. Stright line configuration of optical fiber The optical fiber sensor consists of two terminals. the input terminal that conected to laser source 1310nm. and the output terminal connected to the photodetector to convert the signal from the laser wave to the voltage level. The middle part of the fiber optic sensor is peeled off the jacket and the peeled part is installed embedded in a concrete beam. 2.2. Design of Reinforced Concrete Beams with an Embedded Sensor Concrete beams used in this study are lightweight reinforced concrete beams with 20MPa compressive strength. In order to reach a lightweight, plastic gravel is used [9] The size of the concrete blocks made is 8x16x160 cm. Fiber optic sensors are implanted in concrete with the straight configuration in Figure 2. The mix design of concrete is shown in Table 1. ICETIR 2020 IOP Publishing IOP Conf. Series: Materials Science and Engineering 982 (2020) 012025 doi:10.1088/1757-899X/982/1/012025 Figure 2. Model of concrete beam samples with embedded sensors Table 1. The mix design of concrete. Concrete Volume (Kg) - Plastic materials 1 M3 2*Sil 10/20 & * 1Sil 15/30 Cement 500 17,14 sand 845 28,96 Naturak gravel 0 0 Plastic gravel 432 14,8 SP Sika LN 12 0,4 water 150 5,14 2.3. Data Acquisition and Analysis Data acquisition is done by flexural testing using UTM. Concrete deflection is measured using LVDT. The observed data are changes in concrete deflection and changes in the optical fiber sensor output voltage due to loading on the concrete beam. The data acquisition scheme is shown in Figure 3. ICETIR 2020 IOP Publishing IOP Conf. Series: Materials Science and Engineering 982 (2020) 012025 doi:10.1088/1757-899X/982/1/012025 Figure 3. Data retrieval scheme 3. Result and Discussion 3.1. Data The fiber optic configuration in the concrete is shown in Figure 4, and the reinforced concrete block with embedded sensors is shown in Figure 5. Figure 4. fiber optic configuration inside the concrete mold Figure 5. Flexural testing concrate beam sample with embedded fiber optic In this study data were taken from 3 concrete beam samples with embedded sensors. The results of the data from the first concrete beam are shown in Table 2. The second concrete beam in Table 3 and the third concrete beam in Table 4. Tabel 2. The first concrete beam sample data ICETIR 2020 IOP Publishing IOP Conf. Series: Materials Science and Engineering 982 (2020) 012025 doi:10.1088/1757-899X/982/1/012025 Output voltage no load (kN) deflection (mm) optical fiber sensors (volt) 1 0.004941041 0.00000487 0.37 2 0.11957637 0.22377928 0.56 3 0.57090282 0.32311198 1.12 4 1.7325027 0.83081281 1.49 5 3.65113 1.196736 1.68 6 6.0351171 1.8259418 2.43 7 8.5939245 2.5912743 2.61 8 10.107606 3.0649996 3.17 9 14.518381 4.418685 3.55 10 16.03191 5.8213181 3.73 11 16.907057 8.036375 3.92 12 17.398458 9.9108582 4.11 13 17.840471 13.267413 4.48 Tabel 3. Second concrete beam sample data Output voltage no load (kN) deflection (mm) optical fiber sensors (volt) 1 0.068897821 0.036128148 0.4 2 0.51017541 0.52297401 0.6 3 1.1495951 0.72594935 0.81 4 2.6247454 1.1949829 1.01 5 3.5582852 1.4596689 1.41 6 5.3155766 2.051162 1.81 7 7.4279442 2.8705878 2.01 8 9.6917734 3.6616268 2.21 9 10.854418 4.0441976 2.62 10 13.480095 4.8764434 2.82 11 15.15642 5.4440699 3.02 12 15.846836 6.1979642 3.22 ICETIR 2020 IOP Publishing IOP Conf. Series: Materials Science and Engineering 982 (2020) 012025 doi:10.1088/1757-899X/982/1/012025 13 16.391153 6.8814449 3.62 14 16.709873 7.5666599 3.82 15 17.527981 12.060499 4.23 16 17.753162 22.424404 4.43 17 18.186796 38.390656 4.83 Tabel 4. Third concrete beam sample data Output voltage no load (kN) deflection (mm) optical fiber sensors (volt) 1 0.82641274 0.036763895 0.35 2 2.0133584 0.21275349 0.53 3 3.6153882 0.54891306 1.06 4 5.2496629 0.95169693 1.24 5 7.0092497 1.5461302 1.42 6 8.5411425 2.0465524 1.77 7 9.6772785 2.417012 1.95 8 11.71697 3.1238008 2.13 9 13.75316 3.8872695 2.3 10 14.499065 4.8545823 2.66 11 14.689847 6.7961712 3.19 12 15.386856 8.257062 3.54 13 16.247229 12.41567 4.08 14 16.62388 27.62908 4.25 15 17.472326 55.628048 4.61 Based on the test results with UTM, we obtain that the reinforced concrete beam has a maximum average load capacity of 17,833kN. While the mean deflection of reinforced concrete beams when loading is 35.62 mm. The average sensor output voltage when the concrete beam reaches its maximum capacity reaches the average of 4.64volt. From table 1, table 2 and table 3 it can be seen that both deflection and sensor output voltage increases with increasing loading test ICETIR 2020 IOP Publishing IOP Conf. Series: Materials Science and Engineering 982 (2020) 012025 doi:10.1088/1757-899X/982/1/012025 3.2. Sensitivity Analysis of Optical Fiber Sensors Sensitivity analysis is done by graphing the relationship between the deflection of the concrete beam and the optical fiber sensors output voltage. To determine the sensitivity, a linear region determined from the response of the fiber optic sensor, then a linear approach analysis is performed. 3.2.1. Embeded Sensor 1. Embedded sensor 1, is an optical fiber sensors that is embedded in the second concrete beam. The graph results for Embedded sensor 1 are shown in Figure 6. Embeded sensor 1 4,5 3,5 2,5 1,5 0,5 0 2 4 6 8 10 12 14 Deflection (mm) Figure 6. Graph of the relationship between the deflection of a concrete beam and the optical fiber sensor output voltage from first sensor. In Figure 6 can be seen that there are two different linear regions. This shows that the senor has different sensitivity values for two different linear regions. Graph linear 1a where the deflection value is less than 5 mm. The linear region 1b where the deflection value is more than the same as 5 mm. The results of the linear approach are shown in Figure 7 and Figure 8 Linear 1a 4,5 3,5 2,5 y = 0,7253x + 0,7201 R² = 0,9374 1,5 0,5 0 1 2 3 4 5 Deflection (mm) output voltage of fiber optic sensor output voltage of fiber optic sensor volt volt ICETIR 2020 IOP Publishing IOP Conf. Series: Materials Science and Engineering 982 (2020) 012025 doi:10.1088/1757-899X/982/1/012025 Figure 7. Linear approach 1a In the linear region 1a in the deflection range below 5mm, the optical fiber sensor has a sensitivity of 0.7253volt / mm. Linear 1b 4,5 3,5 y = 0,1014x + 3,1213 R² = 0,9966 2,5 1,5 0,5 0 2 4 6 8 10 12 14 Deflection (mm) Figure 8. Linear approach 1b In the linear region 1b, where the deflection range is more than or equal to 5mm, the fiber optic sensor has a sensitivity of 0.1014volt / mm. For embedded sensor 1, the sensitivity ratio of linear region 1a to linear region 1b reaches 7.15: 1 3.2.2. .Embedded Sensor 2. Embedded sensor 2, is an optical fiber sensor that is embedded in the second concrete beam. The graph results for Embedded sensor 2 are shown in Figure 9. Embeded sensor 2 0 5 10 15 20 25 30 35 40 45 Deflection (mm) output voltage of fiber optic sensor output voltage of fiber optic sensor volt volt ICETIR 2020 IOP Publishing IOP Conf. Series: Materials Science and Engineering 982 (2020) 012025 doi:10.1088/1757-899X/982/1/012025 Figure 9. Graph of the relationship between the deflection of a concrete beam and the optical fiber sensor output voltage from second sensor. In Figure 9, there are two linear region. Liear 2a show in Figure 10 and linear 2 b show in Figure Linear 2a 3,5 2,5 y = 0,4585x + 0,5566 R² = 0,9763 1,5 0,5 0 1 2 3 4 5 6 7 8 Deflection (mm) Figure 10. Linear approach 2a In the deflection range of concrete beams less than 8mm, optical fiber sensors embedded in concrete have a sensitivity of 0.4585volt / mm. Linear 2b 4,9 4,8 4,7 4,6 4,5 y = 0,023x + 3,9385 4,4 R² = 0,9954 4,3 4,2 4,1 0 5 10 15 20 25 30 35 40 45 Deflection (mm) Figure 11. Linear approach 2b output voltage of fiber optic sensor output voltage of fiber optic sensor volt volt ICETIR 2020 IOP Publishing IOP Conf. Series: Materials Science and Engineering 982 (2020) 012025 doi:10.1088/1757-899X/982/1/012025 In the deflection range of concrete beam more than the same as 8mm, optical fiber sensors embedded in concrete have a sensitivity of 0.023volt / mm. The ratio of linear sensitivity 2a to linear 2b is 19.93: 1 3.2.3. Embeded Sensor 3. The Embedded sensor 3 is an optical fiber sensors that embedded in the third concrete beam. The graph results for Embedded sensor 3 are shown in Figure 12. Embeded Sensor 3 0 10 20 30 40 50 60 Deflection (mm) Figure 12. Graph of the relationship between the deflection of a concrete beam and the optical fiber sensor output voltage from third sensor. Figure 12 shows the existence of two linear regions. The linear region in the deflection range is less than 9 mm, referred as the linear region 3a shown in Figure 13, and the linear region in the deflection range is greater than 9mm called the linear region 3b shown in Figure 14. Linear 3a 3,5 2,5 y = 0,3652x + 0,7895 1,5 R² = 0,9439 0,5 0 1 2 3 4 5 6 7 8 9 Deflection (mm) Figure 13. Linear approach 3a output voltage of fiber optic sensor output voltage of fiber optic sensor volt volt ICETIR 2020 IOP Publishing IOP Conf. Series: Materials Science and Engineering 982 (2020) 012025 doi:10.1088/1757-899X/982/1/012025 In the deflection range of less than 9mm, the fiber optic sensor has a sensitivity of 0.3652 volts / mm. Linear 3b 4,7 y = 0,0123x + 3,9198 4,6 R² = 0,9988 4,5 4,4 4,3 4,2 4,1 0 10 20 30 40 50 60 Deflection (mm) Figure 14. linear approch 3b In the deflection range above 9 mm, the optical fiber sensors have a sensitivity of 0.0123volt / mm. The sensitivity ratio of 3a to 3b is 29.69: 1. Based on data retrieval from the three sensors, it can be seen that the sensor has a good sensitivity in the linear a region with an average sensitivity of (0.7253volt / mm + 0.4585volt / mm + 0.3652 volts / mm) / 3 = 0.5613volt / mm. The average of effective working area is for deflection value less than 7.33mm 4. Conclusion Optical fiber sensor embedded with a straight configuration in concrete has a sensitivity related to the changes of reinforced concrete beam deflection in the number of 0.5613volt / mm and the average of effective working area is for deflection value less than 7.33mm References th [1] K. Fidanboylu and Efendioglu, H.S., “Fiber Optic Sensors and Their Applications,” 5 International Advanced Symposium (IATS'09). May, 2009. [2] S. Ahmad, M. U. Rizvi, S. Mohd, A. Husain, and A. Anwar, “Study of Fiber Optic Sensor Using Concrete Beams,” pp. 2319–2322, 2014. [3] Asriani Farida, Pamudji Gandjar, and Susilawati, H. “Pengembangan Deteksi Kerusakan Beton yang Menggunakan Agregat Sampah Plastik Dengan Sensor Fiber Optik Multi Mode Tertanam,” in Seminar Nasional Ketekniksipilan Bidang Vikasional III, 2016. [4] C. G. Berrocal, I. Fernandez, and R. Rempling, “Crack monitoring in reinforced concrete output voltage of fiber optic sensor volt ICETIR 2020 IOP Publishing IOP Conf. 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Satim, “Influence of uncoated and coated plastic waste coarse aggregates to concrete compressive strength,” MATEC Web Conf., vol. 101, 2017. [10] P. Gandjar, H. Bimasena, P. A. Yuta, and P. Heru, “Bond-Slip Behavior of Steel Bar Embedded in Lightweight Concrete Using Sand Coated Polypropylene Coarse Aggregate,” Mater. Sci. Forum, vol. 929, pp. 103–108, 2018.

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Published: Dec 18, 2020

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