{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,11]],"date-time":"2026-04-11T01:10:08Z","timestamp":1775869808763,"version":"3.50.1"},"reference-count":42,"publisher":"MDPI AG","issue":"23","license":[{"start":{"date-parts":[[2022,12,2]],"date-time":"2022-12-02T00:00:00Z","timestamp":1669939200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Transport Canada"},{"name":"Natural Sciences and Engineering Research Council of Canada"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Shrinkage is an important component of the behaviour of reinforced concrete (RC) structures, however, the number of variables that affect shrinkage make it a complex time-dependent phenomenon. Additionally, as new concrete materials with lower embodied carbon gain popularity, there is a need for an in-depth understanding into their shrinkage behaviour before they can be widely adopted by industry. Currently, the shrinkage behaviour of concrete is studied using discrete measurements on small-scale unrestrained prisms. Distributed fibre optic sensing (DFOS) potentially provides a method of measuring both restrained (with reinforcement) and unrestrained (without reinforcement) shrinkage in both small-scale specimens and structural elements. In the current study, methods of measuring distributed unrestrained shrinkage strains were developed and evaluated, and the restrained shrinkage strains in different types of structural members were studied. Unrestrained shrinkage strains were measured using fibres optic cables embedded in small concrete prisms, while restrained shrinkage strains were measured with fibres bonded to the longitudinal reinforcement. Unrestrained shrinkage strains were found to be highly variable (as large as 3800 microstrain range) depending on location, but further research needs to be undertaken to account for end effects, early-stage shrinkage, and bond between the fibre optic cable and the concrete. Restrained shrinkage strains from structural members revealed non-uniform shrinkage strain distributions along member length due to functional grading as well as high supplementary cementitious material concretes, suggesting that shrinkage models will need to account for this variability.<\/jats:p>","DOI":"10.3390\/s22239397","type":"journal-article","created":{"date-parts":[[2022,12,2]],"date-time":"2022-12-02T03:28:04Z","timestamp":1669951684000},"page":"9397","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":11,"title":["Measurement of Restrained and Unrestrained Shrinkage of Reinforced Concrete Using Distributed Fibre Optic Sensors"],"prefix":"10.3390","volume":"22","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9697-4704","authenticated-orcid":false,"given":"Jacob S.","family":"Yager","sequence":"first","affiliation":[{"name":"Department of Civil Engineering, Queen\u2019s University, 58 University Ave., Kingston, ON K7L 3N6, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Neil A.","family":"Hoult","sequence":"additional","affiliation":[{"name":"Department of Civil Engineering, Queen\u2019s University, 58 University Ave., Kingston, ON K7L 3N6, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Evan C.","family":"Bentz","sequence":"additional","affiliation":[{"name":"Department of Civil & Mineral Engineering, University of Toronto, 35 St. George St., Toronto, ON M5S 1A4, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1352-3700","authenticated-orcid":false,"given":"Joshua E.","family":"Woods","sequence":"additional","affiliation":[{"name":"Department of Civil Engineering, Queen\u2019s University, 58 University Ave., Kingston, ON K7L 3N6, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,12,2]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"112955","DOI":"10.1016\/j.engstruct.2021.112955","article-title":"Minimizing embodied energy of reinforced concrete floor systems in developing countries through shape optimization","volume":"246","author":"Ismail","year":"2021","journal-title":"Eng. Struct."},{"key":"ref_2","unstructured":"Neville, A.M. (1995). Properties of Concrete, Longman."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"104058","DOI":"10.1016\/j.cemconcomp.2021.104058","article-title":"Characterization of concrete shrinkage induced strains in internally-restrained RC structures by distributed optical fiber sensing","volume":"120","author":"Bado","year":"2021","journal-title":"Cem. Concr. Compos."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"62","DOI":"10.1016\/j.conbuildmat.2017.05.064","article-title":"Autogenous shrinkage of high performance concrete: A review","volume":"149","author":"Wu","year":"2017","journal-title":"Constr. Build. Mater."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"464","DOI":"10.1016\/j.cemconres.2004.05.009","article-title":"Contribution of mixture design to chemical and autogenous shrinkage of concrete at early ages","volume":"35","author":"Holt","year":"2005","journal-title":"Cem. Concr. Res."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"537","DOI":"10.1016\/j.cemconcomp.2004.09.005","article-title":"Free, restrained and drying shrinkage of cement mortar composites reinforced with vegetable fibres","volume":"27","author":"Ghavami","year":"2005","journal-title":"Cem. Concr. Compos."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"55","DOI":"10.1016\/j.cemconres.2016.04.001","article-title":"Multiscale modeling of drying shrinkage and creep of concrete","volume":"85","year":"2016","journal-title":"Cem. Concr. Res."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"427","DOI":"10.1016\/j.cemconcomp.2009.04.003","article-title":"Volume change and cracking in internally cured mixtures made with saturated lightweight aggregate under sealed and unsealed conditions","volume":"31","author":"Henkensiefken","year":"2009","journal-title":"Cem. Concr. Compos."},{"key":"ref_9","first-page":"35","article-title":"Modeling concrete shrinkage under variable ambient conditions","volume":"96","author":"Torrenti","year":"1999","journal-title":"ACI Mater. J."},{"key":"ref_10","unstructured":"(2017). Standard Test Method for Length Change of Hardened Hydraulic Cement Mortar and Concrete, Annual Book of ASTM Standards (Standard No. ASTM C 157)."},{"key":"ref_11","unstructured":"(2015). Standard Test Method for Creep of Concrete in Compression, Annual Book of ASTM Standards (Standard No. ASTM C 512)."},{"key":"ref_12","first-page":"477","article-title":"High-resolution extended distance distributed fiber-optic sensing using Rayleigh backscatter","volume":"6530","author":"Kreger","year":"2007","journal-title":"Sens. Syst. Netw. Phenom. Technol. Appl. NDE Health Monit."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"118","DOI":"10.1680\/stbu.13.00070","article-title":"Concrete deterioration detection using distributed sensors","volume":"168","author":"Regier","year":"2015","journal-title":"Proc. Inst. Civ. Eng. Struct. Build."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Barrias, A., Casas, J.R., and Villalba, S. (2018). Embedded distributed optical fiber sensors in reinforced concrete structures\u2014A case study. Sensors, 18.","DOI":"10.3390\/s18040980"},{"key":"ref_15","first-page":"255","article-title":"Understanding Reinforcement Behavior Using Distributed Measurements of Shear Tests","volume":"118","author":"Poldon","year":"2021","journal-title":"ACI Struct. J."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"123612","DOI":"10.1016\/j.conbuildmat.2021.123612","article-title":"Evaluating the behaviour of functionally graded reinforced concrete without transverse reinforcement using distributed sensing","volume":"295","author":"Yager","year":"2021","journal-title":"Constr. Build. Mater."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"441","DOI":"10.1016\/j.ymssp.2012.01.027","article-title":"Application of optical fiber distributed sensing to health monitoring of concrete structures","volume":"39","author":"Villalba","year":"2013","journal-title":"Mech. Syst. Signal Process."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"57","DOI":"10.14359\/51710870","article-title":"Monitoring reinforced concrete serviceability performance using fiber-optic sensors","volume":"116","author":"Brault","year":"2019","journal-title":"ACI Struct. J."},{"key":"ref_19","first-page":"245","article-title":"Shear-critical deep beams with embedded functionally graded concrete struts","volume":"119","author":"Yager","year":"2022","journal-title":"ACI Struct. J."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"490","DOI":"10.1016\/j.cemconcomp.2007.02.003","article-title":"Simultaneous measurement of shrinkage and temperature of reactive powder concrete at early-age using fibre Bragg grating sensors","volume":"29","author":"Wong","year":"2007","journal-title":"Cem. Concr. Compos."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"473","DOI":"10.1016\/S0958-9465(03)00077-5","article-title":"Experimental investigation into early age shrinkage of cement paste by using fibre Bragg gratings","volume":"26","author":"Slowik","year":"2004","journal-title":"Cem. Concr. Compos."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Coetzee, W.Z., Van Eck, S., Grobler, M.F., Vannucci, M.J., Manuel, R.M., and Bester, J. (2015, January 14\u201317). Embedded Fibre Bragg Gratings to measure shrinkage during the early age of concrete. Proceedings of the AFRICON, Addis Ababa, Ethiopia.","DOI":"10.1109\/AFRCON.2015.7331957"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"115","DOI":"10.1680\/macr.2008.62.2.115","article-title":"Shrinkage of Hong Kong granite aggregate concrete","volume":"62","author":"Kwan","year":"2010","journal-title":"Mag. Concr. Res."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"753","DOI":"10.14359\/51689463","article-title":"Distributed sensing for shrinkage and tension stiffening measurement","volume":"114","author":"Davis","year":"2017","journal-title":"ACI Struct. J."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1555","DOI":"10.1002\/suco.202100730","article-title":"Assessing beam shear behavior with distributed longitudinal strains","volume":"23","author":"Poldon","year":"2022","journal-title":"Struct. Concr."},{"key":"ref_26","unstructured":"(2019). Concrete Materials and Methods of Concrete Construction (Standard No. CSA A23.1-19)."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"115","DOI":"10.14359\/51714483","article-title":"Distributed Reinforcement Strains: Measurement and Application","volume":"116","author":"Brault","year":"2019","journal-title":"ACI Struct. J."},{"key":"ref_28","unstructured":"Luna Technologies (2022). Luna ODiSI 6000 Data Sheet, Luna Technologies."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"130","DOI":"10.1016\/j.conbuildmat.2011.08.014","article-title":"Modeling of bonding between steel rebar and concrete at elevated temperatures","volume":"27","author":"Pothisiri","year":"2012","journal-title":"Constr. Build. Mater."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"04020145","DOI":"10.1061\/(ASCE)CF.1943-5509.0001559","article-title":"Development of an axial strain measurement system for rails","volume":"35","author":"Barker","year":"2021","journal-title":"J. Perform. Constr. Facil."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"04017144","DOI":"10.1061\/(ASCE)BE.1943-5592.0001189","article-title":"Fiber optic sensors and digital image correlation for measuring deformations in reinforced concrete beams","volume":"23","author":"Green","year":"2018","journal-title":"J. Bridge Eng."},{"key":"ref_32","first-page":"451","article-title":"Creep and Shrinkage of Normal-Strength Concrete with Recycled Concrete Aggregates","volume":"112","author":"Knaack","year":"2015","journal-title":"ACI Mater. J."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1405","DOI":"10.1016\/S0008-8846(98)00102-1","article-title":"Influence of superplasticizer, plasticizer, and silica fume on the drying shrinkage of high-strength concrete subjected to hot-dry field conditions","volume":"28","author":"Alsayed","year":"1998","journal-title":"Cem. Concr. Res."},{"key":"ref_34","unstructured":"Tritsch, N., Darwin, D., and Browning, J. (2005). Evaluating Shrinkage and Cracking Behavior of Concrete Using Restrained Ring and Free Shrinkage Tests, University of Kansas Center for Research."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"1514","DOI":"10.1061\/(ASCE)MT.1943-5533.0000249","article-title":"Shrinkage and fracture properties of semiflowable self-consolidating concrete","volume":"23","author":"Lomboy","year":"2011","journal-title":"J. Mater. Civ. Eng."},{"key":"ref_36","first-page":"877","article-title":"Shrinkage of nanomodified fly ash concrete as repair material","volume":"114","author":"Ghazy","year":"2017","journal-title":"ACI Mater. J."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"362","DOI":"10.4028\/www.scientific.net\/AMM.567.362","article-title":"Drying Shrinkage of Fly Ash-Based Self-Compacting Geopolymer Concrete","volume":"567","author":"Nuruddin","year":"2014","journal-title":"Appl. Mech. Mater."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"9","DOI":"10.4334\/IJCSM.2008.2.1.009","article-title":"Early-age properties of polymer fiber-reinforced concrete","volume":"2","author":"Myers","year":"2008","journal-title":"Int. J. Concr. Struct. Mater."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"1863","DOI":"10.1016\/S0008-8846(99)00178-7","article-title":"Protected paste volume in concrete: Extension to internal curing using saturated lightweight fine aggregate","volume":"29","author":"Bentz","year":"1999","journal-title":"Cem. Concr. Res."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"117","DOI":"10.1016\/j.cemconres.2017.02.019","article-title":"Consequences of longer sealed curing on drying shrinkage, cracking and carbonation of concrete","volume":"95","author":"Samouh","year":"2017","journal-title":"Cem. Concr. Res."},{"key":"ref_41","unstructured":"(2008). ACI Committee 209, Prediction of Creep, Shrinkage and Temperature Effects in Concrete Structures (Standard No. ACI 209R-08)."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"326","DOI":"10.1016\/j.conbuildmat.2014.06.050","article-title":"Comparison of theoretical and experimental shrinkage in concrete","volume":"72","year":"2014","journal-title":"Constr. Build. Mater."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/22\/23\/9397\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T01:32:33Z","timestamp":1760146353000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/22\/23\/9397"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,12,2]]},"references-count":42,"journal-issue":{"issue":"23","published-online":{"date-parts":[[2022,12]]}},"alternative-id":["s22239397"],"URL":"https:\/\/doi.org\/10.3390\/s22239397","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,12,2]]}}}