تأثیر شرایط عمل آوری، پرداخت سطحی و سرعت بارگذاری بر مقاومت پیوستگی لایه تعمیری از نوع بتن خود تراکم حاوی الیاف فولادی با بستر بتنی معمولی به روش pull-off

نوع مقاله : مقاله پژوهشی

نویسندگان

1 گروه عمران،دانشکده فنی،دانشگاه گیلان،رشت،ایران

2 استاد گروه عمران-دانشگاه گیلان

3 عضو هیات علمی دانشگاه گیلان

10.22124/jcr.2021.20460.1511

چکیده

از عوامل بسیار مهم در عملکرد یکپارچه لایه تعمیری و بتن قدیمی، چسبندگی بین این دو می باشد. اندازه گیری دقیق چسبندگی تحت تاثیر عواملی چون مقاومت و شرایط سطحی بتن قدیم، مکانیزم اعمال نیرو و شرایط محیطی موثر بر عمل آوری لایه تعمیری می باشد. در این پژوهش در مجموع 8 طرح اختلاط ساخته شد. جهت بررسی تاثیر تراز مقاومت و کیفیت لایه بستر، دو رده بتن با مقاومت هایی در محدوده20-30 و 40-50 مگاپاسکال و دو نوع سطح، پرداخت شده و با شیار مورد بررسی قرار گرفت. لایه های تعمیری بتن ها با سه رده مقاومتی بتن خودتراکم حاوی 5/0 و 1 و2 درصد حجمی الیاف فولادی ترمیم شد. نمونه ها بعد از ساخت در سه شرایط عمل آوری هوای آزاد، استاندارد و تسریع شده با آب گرم قرار گرفتند. آزمون های مقاومت فشاری، خمشی و کشش غیر مستقیم بروی طرح های مورد استفاده بعنوان لایه تعمیری انجام شد و جهت ارزیابی مقاومت پیوستگی بین لایه ها، آزمون Pull off استفاده شد. نتایج آشکار ساختند که تاثیر مقاومت بتن بستر به مراتب مهمتر از اثر مقاومتی لایه تعمیری است و همچنین تاثیر شرایط عمل آوری نسبت به شرایط پرداخت و آماده سازی بستر به مراتب بیشتر بود. مقاومت پیوستگی طرح های حاوی 5/0درصد الیاف فولادی در رده های C50، C60 و C70 و با عمل آوری در آب گرم پس از 28 روز بترتیب 105، 108 و 104 درصد بالاتر از نمونه های عمل‌آوری شده در هوای آزاد بوده است.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Effect of curing, finishing and loading rate on the bond strength of fiber reinforced SCC layer with normal concrete by pull-off method

نویسندگان [English]

  • Omolbanin Arasteh 1
  • Rahmat Madandoust 2
  • Malekmohammad Ranjbar Taklimi 3
1 Civil Engineering, Guilan University
2 Department of Civil Engineering, Faculty of Engineering, Guilan University, Rasht
3 Department of Civil Engineering, Faculty of Engineering, Guilan University, Rasht
چکیده [English]

The main factor in integrated performance of repair overlay and substrate concrete is the bonding between them. The accurate measurement of bonding is dependent to factors such as strength and surface characteristics of substrate concrete, loading mechanism and curing condition of overlay. In this research, 8 mix designs are considered. For assessment of strength level and surface quality of substrate, two concrete grades in the ranges of 20-30 and 40-50 MPa, and also two surface conditions including simple finishing and ribbed finishing were considered. Repair overlays were considered from three different strength grades of self-compacting concretes contained 0.5% and 1% of steel fibers. After fabrication, for curing, three different conditions of curing in open air, curing in warm water, and standard curing were deemed. Compressive strength, flexural strength and splitting tensile strength tests were performed on samples, and Pull-Off method were used for evaluation of bonding strength. The results indicated that the impact of substrate strength on bonding is more significant than overlay strength, and also the effect of curing condition was more salient than finishing quality. The bonding strength of overlays contained 0.5% of steel fibers and with strength grades of C50, C60 and C70 cured in warm water were 105%, 108% and 104%, respectively, higher than same samples cured in open air.

کلیدواژه‌ها [English]

  • Pull-Off
  • Self-compacting concrete
  • Steel fibers
  • Repair overlay
  • Curing condition

مراجع

[1] Momayez, A., Ehsani, M. R., Ramezanianpour, A. A. and Rajaie, H. (2005) "Comparison of methods for evaluating bond strength between concrete substrate and repair materials," Cement and Concrete Research vol. 35 pp. 748–757.
[2] قدوسیان، ا,(1389) "تعیین چسبندگی بتن خودمتراکم بر بسترهای مختلف بتنی با استفاده از روش های پیچش و انتقال اصطکاک," دانشگاه بین المللی امام خمینی.
[3] ASTM, (1999) "C1042-99 : Standard test method for bond strength of latex systems used with concrete by Slant shear," ed: ASTM International.
[4] Pedro, M. D. S., Eduardo, J. and Vitor, D. S. (2007) "Correlation between concrete-to-concrete bond strength and the roughness of the substrate surface," Construction and Building Materials, vol. 21, pp. 1688-1695.
[5] Bungey J. H, Madandoust R. Factors influencing pull-off tests on concrete. Mag. Conc. Res. 1992;44(158):21-30.
[6] Long AE, Murray AMcC. The pull-off partially destructive test for concrete. In: Malhotra VM, editor. Proc. Int. Conf. on In-SiturNon-Destructive Testing of Concrete, Ottawa, Canada, October. ACI SP-82, 1984:327-350.
[7] Carino NJ. ,(1994), “Nondestructive Testing of Concrete: History and Challenges”, ACI SP-144, Concrete Technology - Past, Present and Future, P.K. Mehta, Ed., American eoncrete Institute, Detroit, MI, pp 623-678.
[8] Bungey JH, Soutsos MN. Reliability of partially-destructive tests to assess the strength of concrete on site. Constr Build Mater 2001;15(2–3):81–92.
[9] Ramos N.M.M. , Simões M.L., Delgado J.M.P.Q., Freitas V.P. de, Reliability of the pull-off test for in situ evaluation of adhesion strength, Construction and Building Materials 31 (2012) 86–93.
[10] Bonaldo E, Barros J.A.O, Lourenco, P.B., (2005), Bond characterization between concrete substrate and repairing SFRC using pull-off testing, International Journal of Adhesion & Adhesives 25, 463–474.
[11] Austin, S., Robins, P., Pan, P., Tensile bond testing of concrete repairs, Materials and Structures, 1995, 28, 249-259.
[12] Vaysburd, A.M., McDonald, J.E., (1999), An Evaluation of Equipment and Procedures for Tensile Bond Testing of Concrete Repairs, Technical Report REMR-CS-61, Prepared for Headquarters, U.S. Army Corps of Engineers.
[13] Delatte, N.J., Williamson, M. S. and Fowler, D. W. (2000) "Bond strength development of high-earlystrength bonded concrete overlays," ACI Materials Journal, pp. 201–207.
[14] Schrader, E. K. (1992) "Mistakes, misconceptions, and controversial issues concerning concrete and concrete repairs," Concrete International, vol. Parts 1, 2, and 3.
[15] Banthia, N., Gupta, R. and Mindess, S. (2006) "Development of fiber reinforced concrete repair materials," Can. J. Civ. Eng., vol. 33, pp. 126-133.
[16] Laurence, O., Bissonnette, B., Pigeon, M. and Rossi, P. (2000) "Effect of steel macro fibres on cracking of thin concrete repairs.," In Proceedings, 5th International RILEM Symposium on FibreReinforced Concretes (BEFIB 2000), pp. 213–222.
[17] Talbot, C., Pigeon, M., Beaupre, D. and Morgan, D. (1994) "Influence of surface preparation on long-term bonding of shotcrete," ACI Mater J, pp. 560-6.
[18] Bissonnette, B., Pierre, P. and Pigeon, M. (1999) "Influence of key parameters on drying shrinkage of cementitious materials," vol. 29, pp. 1655-1662.
[19] Julio, E. N. B. S., Branco, F. A. B. and Silva, V. D. (2004) "Concrete-to-concrete bond strength. Influence of the roughness of the substrate surface," Construction and building materials, vol. 18, pp. 675-681.
[20] Haddad, R.H., AL-Mekhlafy, N., Ashteyat, A.M. (2011) "Repair of heat-damaged reinforced concrete slabs using fibrous composite materials", Construction and Building Materials, Vol. 25(3), P.P. 1213-1221.
[21] Ghavidel R., Madandoust R., Ranjbar M.M. (2015) "Reliability of pull-off test for steel fiber reinforced self-compacting concrete", Measurement, Vol. 73, P.P. 628-639.
[22] Zanotti C., Borges P.H.R., Bhutta A., Banthia N. (2017) "Bond strength between concrete substrate and metakaolin geopolymer repair mortar: Effect of curing regime and PVA fiber reinforcement", Cement and Concrete Composites, Vol. 80, P.P. 307-316.
[23] ASTM C496, Standard Test Method for Splitting Tensile Strength of Cylindrical Concrete Specimens, ASTM International, West Conshohocken, Pennsylvania, USA
[24] ASTM C192, Standard Practice for Making and Curing Concrete Test Specimens in the Laboratory, ASTM International, West Conshohocken, Pennsylvania, USA.
[25] Fernando López Gayarre F.L., Pérez C.L.C., López M.A.S., (2014), The effect of curing conditions on the compressive strength of recycled aggregate concrete. Construction and Building Materials; 53: 260-266.
[26] ASTM C1768, Standard Practice for Accelerated Curing of Concrete Cylinders, ASTM International, West Conshohocken, Pennsylvania, USA.
[27] BS EN 206:2013, Concrete- Specifications, performance, production and conformity, British Standards Institution, London, 2013.
[28] Carmona S, Aguado A, Molins C., (2013), Characterization of the properties of steel fiber reinforced concrete by means of the generalized Barcelona test. Construction and Building Materials; 48:592–600.
[29] ASTM C 1609, (2010), Standard test method for Flexural Performance of Fiber-Reinforced Concrete (Using Beam with Third-Point Loading). American Standards for Testing and Materials.
[30] P. Aitcin, R. J. Flatt, Science and Technology of Concrete Admixtures, Woodhead Publishing.
[31] Beushausen, H. (2005) "Long-term performance of bonded concrete overlays subjected to differential shrinkage," University of Cape Town.
[32] Zhou, J., Ye, G., Schlangen, E. and Breugel, K. V. (2008) "Modelling of stresses and strains in bonded concrete overlays subjected to differential volume changes," cement & Concrete Composites, vol. 49, pp. 199-205.
[33] Jr., J. E. B. and Berton, S. (2004) "Simulation of shrinkage induced cracking in cement composite overlays," Cement and concrete research, vol. 26, pp. 861-871.
[34] Roziere, E., Granger, S., Turcry, P. and Loukili, A. (2007) "Influence of paste volume on shrinkage cracking and fracture properties of self-compacting concrete," Cement and concrete research, vol. 29, pp. 626-636.
[35] Tayeh, B. A., Bakar, B. H. A., Johari, M. A. M. and Voo, Y. L. (2012) "Mechanical and permeability properties of the interface between normal concrete substrate and ultra high performance fiber concrete overlay," Cement and Concrete Research, pp. 538-548.

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