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Advances in Materials Science and Engineering
Volume 2016, Article ID 4082926, 13 pages
http://dx.doi.org/10.1155/2016/4082926
Research Article

Crack Risk Evaluation of Early Age Concrete Based on the Distributed Optical Fiber Temperature Sensing

1College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 100124, China
2Department of Mechanical Engineering, State University of New York at Stony Brook, Stony Brook, NY 11794, USA

Received 29 March 2016; Accepted 31 July 2016

Academic Editor: Belal F. Yousif

Copyright © 2016 Nannan Shi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Cracks often appear in concrete arch dams, due to the thermal stress and low tensile strength of early age concrete. There are three commonly used temperature controlling measures: controlling the casting temperature, burying cooling pipe, and protecting the surface. However, because of the difficulty to obtain accurate temperature and thermal stress field of the concrete, the rationality and economy of these measures are not assessed validly before and after construction. In this paper, a crack risk evaluation system for early age concrete is established, including distributed optical fiber temperature sensing (DTS), prediction of temperature and stress fields, and crack risk evaluation. Based on the DTS temperature data, the back-analysis method is applied to retrieve the thermal parameters of concrete. Then, the temperature and thermal stress of early age concrete are predicted using the reversed thermal parameters, as well as the laboratory test parameters. Finally, under the proposed cracking risk evaluation principle, the cracking risk level of each concrete block is given; the preliminary and later temperature controlling measures were recommended, respectively. The application of the proposed system in Xiluodu super high arch dam shows that this system works effectively for preventing cracks of early age concrete.