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Open AccessArticle

Experimental Study of Crack Propagation in Cracked Concrete

by Siyao Wang 1,2 and Shaowei Hu 1,2,*
1
School of Water Resources and Hydropower Engineering, Wuhan University, Wuhan 430072, China
2
Materials & structural Engineering Department, Nanjing Hydraulic Research Institute, Nanjing 210029, China
*
Author to whom correspondence should be addressed.
Energies 2019, 12(20), 3854; https://doi.org/10.3390/en12203854
Received: 18 September 2019 / Revised: 10 October 2019 / Accepted: 10 October 2019 / Published: 12 October 2019
The intersection of cracks has an important role in the key technology of hydraulic fracturing for enhancing the recovery of tight hydrocarbon reservoirs. On the basis of digital image correlation technology, three-point bending tests of concrete beams with an edge crack and a central preset crack were conducted to investigate the propagation of cracks after intersection in concretes. Concrete beams with cracks of different positions, lengths, and approach angles were tested, and results were analyzed. In conclusion, the crack positions, crack lengths, and approach angles significantly influence the crack propagation in naturally cracked concrete. A large distance between the crack tip and central point at the preset transverse crack and crack length indicate a high possibility of the edge crack vertically crossing the preset crack. In particular, the crack restarts from the preset crack tip after intersection when the distance between two cracks is smaller than 30 mm and when the preset crack length is smaller than 40 mm. A large approach angle corresponds to a large carrying capacity of the beam and a high possibility of the crack propagating perpendicularly. An improved criterion of restart cracking after interaction is proposed, and the restart points of all tested beams are predicted and compared with the experimental results. A good agreement is observed, which proves that this criterion is reliable. View Full-Text
Keywords: crack propagation; concrete; preset crack; criterion; interaction crack propagation; concrete; preset crack; criterion; interaction
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MDPI and ACS Style

Wang, S.; Hu, S. Experimental Study of Crack Propagation in Cracked Concrete. Energies 2019, 12, 3854.

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