Bond Strength of Fiber-Reinforced Mortar and Concrete Interface under Pre-Stress

Document Type : Regular Paper

Authors

1 PhD in Structural Engineering, Department of Civil Engineering, Engineering Faculty, Imam Khomeini International University, Qazvin, Iran

2 Professor, Department of Civil Engineering, Engineering Faculty, Imam Khomeini International University, Qazvin, Iran

Abstract

Shrinkage and improper compaction of the repair layer are among the main reasons for the adhesion drop. Shrinkage results in cracking and improper compaction causes fine pores in the interface. Due to the fact that shrinkage and non-compacting are the main reasons for reducing strength and adhesion, therefore, in this paper, research has been done in this regard. The present study aimed to investigate the effect of polypropylene fibers on the shrinkage of mortars and bond of mortar/concrete interface. Moreover, the impact of diverse pre-stresses on the adhesion between mortar and concrete was evaluated by imposing pre-stresses on fiber-reinforced mortars. Adhesion was assessed by the “twist-off” and “pull-off” tests. Furthermore, the effect of fibers and pre-stress on the adhesion examined using SEM images and X-ray diffraction. It is necessary to assess the compressive strength of concrete and mortar in the field. Therefore, the aforementioned semi-destructive methods were employed to investigate the in-situ compressive strength of mortars at different ages. For this purpose, the correlation coefficient between the in-situ and laboratory methods was defined and the scaling curves were plotted to convert the in-situ test results into compressive strengths of the mortars. The obtained findings indicated the positive effect of pre-stress on adhesion. In addition to their mechanical effect, the indirect effect of fibers on the chemical properties of the mortars reduces shrinkage and augments adhesion. Moreover, given the great relationship among the conclusion of “pull-off” and “twist-off” methods, the cost-efficient and available twist-off apparatus can be used for adhesion measurement instead of the costly and import pull-off apparatus. Adding 0.3% of polypropylene fibers to the mortars enhanced the bond strength by 76.8% and 41.7%, respectively and reduced the shrinkage of the mortars by 11%. An initial stress of 0.5 kg/cm2 increased the shear and tensile bond strength at the age of 90 days by 12.8% and 13.3%, respectively.

Keywords

Main Subjects


[1] Maryoto, A. The Effect of Compaction Method on Compressive Strength of Self Compacting Concrete in Laboratory. 1st International Conference on Material Science and Engineering for Sustainable Rural Development, AIP Conf. Proc. 2094, 020002-1 – 020002-7, (2019).
[2] Tuncan, M., Arioz, O., Ramyar, K., and Karasu, B. Effect of Compaction on Assessed Concrete Strength. pp. 847-853, (2014).
[3] Junior, R. A., Lima, M. G., and Oliveira, A. Influence of different compacting method on concrete compressive strength. Journal of Materials, Rio de Janeiro, vol. 23, no.3, (2018).
[4] Alsadey. S., Salem. M. Influence of Polypropylene Fiber on Strength of Concrete. American Journal of Engineering Research. 5(7). p. 223-226, (2016).
[5] Alam. M., Ahmad. I., Rehman. F. Experimental Study on Properties of Glass Fiber Reinforced Conrete. International Journal of Engineering Trends and Technology. 24(6). p. 297-301, (2015).
[6] ACI Committee 544, Report 544.1R-96. State-of-the-Art Report on Fiber Reinforced Concrete, Concr. Int., ACI Manual of Concrete Practice, Part 5, (2009).
[7] Shakir A. Salih & Maha E. AL-Azaawee.. Effect of Polypropylene Fibers on Properties of Mortar Containing Crushed Brick as Aggregate. Journal of engineering and technology. Vol.26.No.12, pp. 1508-1513, (2008).
[8] H.A. MesbahU, F. Buyle-Bodin. Efficiency of polypropylene and metallic fibres on control of shrinkage and cracking of recycled aggregate mortars. Construction and Building Materials 13. pp. 439-447, (1999).
[9] A. SADRMOMTAZI AND A. FASIHI. INFLUENCE OF POLYPROPYLENE FIBERS ON THE PERFORMANCE OF NANO-SIO2-INCORPORATED MORTAR . Iranian Journal of Science & Technology, Transaction B: Engineering, Vol. 34, No. B4, pp 385-395, (2010).
[10] R., A., S., Mohamed. Effect of polypropylene fibers on the mechanical properties of normal concrete. Journal of Engineering Sciences, Assiut University, Vol. 34, pp. 1049-1059, (2006).
[11] D., S., Dharan, A., Lai, Study the effect of polypropylene fiber in concrete. International Research Journal of Engineering and Technology, Vol. 03 – 06, pp. 616-619. (2016).
[12] V., S., Vairagade, K., S., Kene, N., V., Deshpande. Investigation on compressive and tensile behavior of fibrillated polypropylene fibers reinforced concrete. Vol. 2-3, pp. 1111-1115, (2012).
[13] Santandrea, M., Imohamed, I. A. O., Jahangir, H., Carloni, C., Mazzotti, C., De Miranda, S., ... & Casadei, P. An investigation of the debonding mechanism in steel FRP-and FRCM-concrete joints. In 4th Workshop on the new boundaries of structural concrete pp. 289-298, (2016).
[14] Bagheri, M., Chahkandi, A., & Jahangir, H. Seismic Reliability Analysis of RC Frames Rehabilitated by Glass Fiber-Reinforced Polymers. International Journal of Civil Engineering, 17(11), 1785-1797, (2019).
[15] Jahangir, H., & Esfahani, M. R. Investigating loading rate and fibre densities influence on SRG-concrete bond behaviour. Steel and Composite Structures, 34(6), 877-889, (2020).
[16] ASTM C808/C805M-18. Standard Test Method for Rebound Number of Hardened Concrete, ASTM International, West Conshohocken, PA, (2018).
[17] ASTM C597-16. Standard Test Method for Pulse Velocity Through Concrete, ASTM International, West Conshohocken, PA, (2016).
[18] ACI Committee 214, Report 214.4R-03. Guide for Obtaining Cores and Interpreting Compressive Strength Results, American Concrete Institute. (2003).
[19] ASTM C900-15. Standard Test Method for Pullout Strength of Hardened Concrete, ASTM International, West Conshohocken, PA. (2015).
[20] Masi. A., Digrisolo. A., Santarsieo. G. arsiero, “Experimental evaluation of drilling damage on the strength of cores extracted from RC buildings. in Proceedings of World Academy of Science, Engineering and Technology, 7(7). p. 749, (2013).
[21] Naderi, M. Friction-Transfer Test for the Assessment of in-situ Strength & Adhesion of Cementitious Materials, Construction & Building Materials, 19 (6) 454-459, (2005).
[22] Naderi M. New Twist-Off Method for the Evaluation of In-Situ Strength of Concrete, Journal of Testing and Evaluation. 35(6). ISSN: 0090-3973, (2007).
[23] ASTM C1583, Standard test method for tensile strength of concrete surfaces and the bond strength or tensile strength of concrete repair and overlay materials by direct tension (pull-off method), West Conshohocken PA, American Society for Testing and Materials. (2004).
[24] Varzaneh, Ali Saberi, and Mahmood Naderi. "Determination of Shrinkage, Tensile and Compressive Strength of Repair Mortars and Their Adhesion on the Concrete Substrate Using" Twist-off" and" Pull-off" Methods." Iranian Journal of Science and Technology, Transactions of Civil Engineering (2020): 1-19.
[25] Varzaneh, Ali Saberi, and Mahmood Naderi. "NUMERICAL AND EXPERIMENTAL STUDY OF SEMI-DESTRUCTIVE TESTS TO EVALUATE THE COMPRESSIVE AND FLEXURAL STRENGTH OF POLYMER-MODIFIED MORTARS AND THEIR ADHESION TO THE CONCRETE SUBSTRATE." Revista Română de Materiale/Romanian Journal of Materials 50.4 (2020): 537-544.
[26] Saberi Varzaneh, Ali, and Mahmood Naderi. "Study of bond strength between polymer-modified mortars/concrete and their mechanical properties using “friction-transfer” and “pull-off” methods." Mechanics of Advanced Composite Structures (2021).
[27] Saberi Varzaneh, Ali, and Mahmood Naderi. "Experimental and Finite Element Study to Determine the Mechanical Properties and Bond Between Repair Mortars and Concrete Substrates." Journal of Applied and Computational Mechanics (2020).
[28] Naderi, Mahmood, and Ali Saberi Varzaneh. "Studying the effect of shrinkage on the bond strength of mortars, applied to substrate concrete, using “Friction-transfer” and “Pull-off” methods." Journal of Structural and Construction Engineering (2021).
[29] VARZANEH, ALI SABERI, and MAHMOOD NADERI. "STUDY OF BOND STRENGTH BETWEEN FIBER-REINFORCED-MORTAR/STEEL AND THEIR MECHANICAL PROPERTIES USING PUSH-OUT, TWIST-OFF AND PULL-OFF METHODS." Revista Română de Materiale/Romanian Journal of Materials 51.2 (2021): 228-238.
[30] Saberi Varzaneh. A., and Naderi. M. Finite Element and Experimental Investigation of In-situ compressive strength of Fiber-Reinforced Mortar and the Effect of Fibers on the Adhesion of Mortar/Steel. advanced design and manufacturing technology. Accepted article. (2021).
[31] Saberi, Varzaneh Ali, and Mahmood Naderi. "Investigation of In-Situ Compressive Strength of Fiber-Reinforced Mortar and the Effect of Fibers on the Adhesion of Mortar/Steel." International Journal of Advanced Design And Manufacturing Technology (2021): 37-48.
[32] Saberi Vaezaneh, Ali, and Mahmood Naderi. "Analyzing the Effect of Polypropylene Fibers on Compressive Behavior, Shrinkage and Bond Strength of Repair Mortars/Concrete Substrate." Journal of Structural and Construction Engineering (2021).
[33] Naderi, Mahmood, and Ali Saberi Varzaneh. "Determination of Compressive and Flexural Strengths of In-situ Pozzolanic Concrete Containing Polypropylene and Glass Fibers Using" Twist-off" Method." Modares Civil Engineering journal 20.5 (2020).
[34] VARZANEH, ALI SABERI, and MAHMOUD NADERI. "COMPARING THE RESULTS OBTAINED FROM IN-SITU METHODS FOR DETERMINING THE STRENGTH OF THE CEMENT MORTARS." Journal of Critical Reviews 7.4 (2020): 555-564.
[35] Varzaneh, Ali Saberi, and Mahmoud Naderi. "Determination of mechanical properties of repair mortars using in situ methods under different curings." EUREKA: Physics and Engineering, (1) (2020): 3-18.
[36] Naderi, Mahmood, Ali Saberi Varzaneh, and Alireza Esmaeli. " Assessment of the application "twist-off" method for determining the in situ compressive and flexural strengths in the fiber concrete." Journal of Structural and Construction Engineering (2021).
[37] Saberi Varzaneh, Ali, and Mahmoud Naderi. "Numerical and experimental study of in-situ methods to evaluate the mechanical properties of fiber-reinforced mortars." AUT Journal of Civil Engineering (2021).
[38] Saberi Varzaneh, Ali, and Mahmoud Naderi. "Numerical and experimental study of in-situ methods to evaluate the mechanical properties of fiber-reinforced mortars." AUT Journal of Civil Engineering (2021).
[39] ASTM C136, Standard test method for sieve analysis of fine and coarse aggregates, West Conshohocken PA, American Society for Testing and Materials (2006).
[40] ASTM C127, Standard test method for density, relative density (specific gravity), and absorption of fine aggregate, West Conshohocken PA, American Society for Testing and Materials (2012).
[41] ASTM C128, Standard test method for relative density (specific gravity) and absorption of coarse aggregate, West Conshohocken PA, American Society for Testing and Materials (2015).
[42] Journal 101 General Specifications of Roads, Vice President for Strategic Planning and Supervision, Tehran, Iran (2013).
[43] Sadeghi, Hassan, Construction Materials and Laboratory, Imam Hossein University, Tehran, Iran, ISBN: 9789644522147, (2009).
[44] Step-by-step method of National Concrete Mixing Plan, Road, Housing and Urban Development Research Center, Tehran, Iran (2008).
[45] C. ASTM C157, Test method for length change of hardened hydraulic cement mortar and concrete, West Conshohocken PA, American Society for Testing and Materials (2008).
[46] ASTM C490, Standard practice for use of apparatus for the determination of length change of hardened cement paste, mortar, and concrete, West Conshohocken PA, American Society for Testing and Materials (2011).
[47] ASTM C109, Standard test method for compressive strength of hydraulic cement mortars (using 2-in. or [50-mm] cube specimens), American Society for Testing and Materials (2013).
[48] Courard, L. "Parametric study for the creation of the interface between concrete and repair products", Journal of materials and structures, 33, 65, (2000).