Journal of Civil Engineering and Urbanism  
Volume 10, Issue 2: 21-23; March 25, 2020  
Various Methods for Determining Cracks in the  
Infrastructure, a Review  
Agamjot Singh   
Department of Civil Engineering, Guru Nanak Dev Engineering Collage, Ludhiana, Punjab, India  
Corresponding author’s Email:  
The paper aimed to present the different ways of determining the cracks. Cracks are the lines on the surface of  
something along which it has split without breaking apart. There are many ways we can determine like with the help  
of strain gauge, DMI technology, etc. In this review, an effort has been made to find out the various methods by  
which we can find the cause and location of the cracks. In this review, various methods, technologies, sensors’  
articles are reviewed and on the basis of that study has been done. This study has been done. This study helps the  
civil engineers and researchers to find out the location and cause of cracks.  
Keywords: crack detection, capacitive strain sensors, soft elastomer capacitor, strain gauge  
temperature change and type of infrastructure, So  
Dilrukshi and Dias (2016) stated about the cracks that the  
building survey and physical model observations  
demonstrate that the movements generated on walls due to  
the temperature of the roof slab follow the pattern of those  
diurnal temperature variations. They explain that the  
pattern (type and location) of cracking depends  
significantly on whether the wall is load-bearing or framed  
by the reinforced concrete elements. They state that cracks  
can be formed in the wall just under the concrete beam or  
at the masonry - concrete beam interface, usually at the  
weaker of the two. Both types of structural arrangements  
give diagonal cracking near the ends of the walls, with the  
crack orientation steeper in load-bearing walls. In long  
walls, the formation of diagonal cracks at the ends is more  
likely, but both types of cracks could form.  
Cracks are one of the main reasons for deterioration of  
infrastructure (Kong et al., 2018). Cracks with no doubt  
are signals for our failure, but in the same phase we have  
to find the reason behind the cracks. We have to find the  
reason so that they can be controlled and we can be safe  
from our vast loss in the economy. Cracks cause can be  
any like temperature, material’s quality or any procedure  
by which we build our structure. The following review of  
the literature confirms the different types of technologies  
by different types scientists and researchers to determine  
the cracks in the slab, concrete, steel bridge, retaining wall  
or any other part of our infrastructure.  
Cracks evaluation by strain gauge  
DMI technology for cracks determining  
Cracks are the building problem to the infrastructure,  
there are many practices which have been done to tackle  
with cracks. For example, De Backer et al. (2003) used the  
strain gauge directly to the concrete surface, as a  
controlling mechanism on the effectiveness of the post-  
tensioning of large concrete beams. They also deliver a  
case study stating the validity of this method. Also when  
the practical execution of the measurements is carried out  
with the utmost precision, this method delivers reliable  
and precise results but taking into account the specific  
working conditions. This problem is also related to  
So as the technology shows its dignity, many new  
technologies come. Ranson et al. (2007) conducted DMI  
technology and in that, they conduct experiments which  
were to demonstrate the utility of the DMI technology to  
measure strain around a hole in a plate subjected to cyclic  
loading and crack growth in the hole and ultimately to the  
surface of the plate. In their experiments, two edges of the  
gage were parallel to the direction of cyclic loading. They  
also tell that the orientation of the gage and its ability to  
detect crack initiation and crack growth is independent of  
To cite this paper: Singh  
A (2020). Various Methods for Determining Cracks in the Infrastructure, a Review. J. Civil Eng. Urban., 10 (2): 21-23. DOI:  
Singh, 2020  
the orientation of the gage, because the gauge measures  
with steeper strain gradients at higher loading stages. Their  
approach to stress transfer can provide very  
comprehensive results of reinforcement and concrete  
strains, the bond stress and slip values over the entire  
distribution of the element, provided the implemented  
bond-slip model was accurate.  
orthogonal extensional strains and associated shear strains.  
They use DMI technology permits periodic inspection of a  
DMI gage centered on a fastener hole containing a fastener  
on in-service equipment to determine the presence of  
cracks at scheduled inspection intervals or after an unusual  
loading. This comment is based on the discussion by  
Timoshenko and Goodier cited above. This does not mean  
that electrical resistance gages do not have a role. They  
also suggest that electrical resistance gages may be more  
economically and technologically informative, if deployed  
differently than currently deployed on surfaces with  
fastener hole.  
SEC (Soft Elastomer Capacitors) and basic  
function on crack estimation  
A study that was focused on examining the suitability  
of a novel large-area strain-based sensing technology for  
monitoring fatigue cracking. Kong et al. (2018) have  
presented a study that was focused on examining the  
suitability of a novel large area strain-based sensing  
technology for monitoring fatigue cracking in steel  
bridges. They take SEC which is a large-size, flexible,  
low-cost, and mechanically-robust capacitive strain gage,  
and has a wide strain measuring range, making it a  
promising tool for monitoring cracks in bridges. Their  
studies have verified the SEC’s capabilities for monitoring  
low-cycle fatigue cracking, but high cycle fatigue cracking  
is characterized by a small crack openings, which presents  
was a new challenge for a capacitance-based sensor such  
as the SEC. To achieve that monitoring solution for  
fatigue cracking in steel bridges, they use the pk-pk  
amplitude of the sensor’s measurement to construct an  
indicator of crack growth. Then they establish a crack  
monitoring algorithm to compute CGIs as a normalized  
pk-pk amplitude in the frequency domain. The sensor’s  
capabilities and the proposed algorithm was evaluated  
through experimental testing under various stress ratios, R.  
They got some conclusions that the developed algorithm  
was able to overcome noise infiltration, and resulted in an  
excellent correlation between increasing fatigue crack  
length and increasing CGI. Therefore, the proposed crack  
monitoring algorithm was validated by the test data. They  
state that the proposed crack monitoring algorithm was  
able to robustly monitor the growth of high cycle fatigue  
cracks under various loading conditions and provide  
consistent results for the three stress ratios that were  
studied. With the introduction of the monitoring algorithm,  
the SEC was found to be capable of serving as a  
monitoring device for propagating fatigue cracks in steel  
FBG optical strain gauge  
To increase the precision for crack determining,  
Kaklauskas et al. (2019) used strain profiles of the  
reinforcement bars attained from the FBG optical strain  
gauge and ordinary tensor strain gauge in a comparison. In  
addition, they carried out numerical calculations using the  
stress transfer approach to obtain the numerical strain  
variation along the reinforced concrete prism reinforcing  
bar. In their experimental techniques, they provide strain  
variations along the steel bar with reasonable accuracy and  
smoothness, however, the specimen strain results of the  
fiber Bragg grating optical gauge test displayed anomalies,  
particularly near the end of the specimen. Then the  
measured strains which they use were larger than the strain  
value estimated for a bare bar assuming the experimental  
value of the modulus of elasticity of the bar. In addition,  
the FBG recordings were lacking consistency regarding  
the symmetry condition of the left and the right side of the  
member. Due to fluctuations in the strain values recorded  
by FBG sensors and the rather rare spacing between the  
sensors, it cannot be firmly asserted whether the  
phenomenon was related to the debonding effect proposed  
in previous research by the authors. Their effect implies  
altered bond behavior between the reinforcement and the  
concrete material surrounding it around the location of the  
cracks or elements’ ends. A comparison of the numerical  
results with appropriate experimental strain curves of the  
steel reinforcement showed that the Model Code 2010  
bond-slip equation could provide sufficiently accurate  
results when coupled with the stress transfer approach for  
the Ø20 mm specimens. However, their additional tests  
with different diameter bars and reinforcement ratios  
would help them either affirm or negate the findings.  
Some discrepancies in numerical and experimental strain  
comparison appeared at the highest loading of the FBG  
specimen. The overall observed behavior was parabolic,  
Detection, localization, and quantification of  
cracks by SEC(soft elastomeric capacitors)  
Yan et al. (2019) studied the novel sensing skin for  
the detection, localization, and quantification of cracks in  
concrete. The sensing skin, constituted from an array of  
J. Civil Eng. Urban., 10 (2): 21-23, 2020  
soft elastomeric capacitors (SECs), is an inexpensive,  
work. However, there can be many alternatives which are  
durable, and robust sensing solution that can be leveraged  
to measure strain over large surfaces. Their strain  
measurement values were collected in the form of discrete  
point values among the network. The spatiotemporal  
comparison of strains enables the detection, localization,  
and quantification of cracks. The sensing skin was first  
introduced and validation results preliminarily conducted  
on small-scale reinforced concrete beams were presented.  
Initial characterization of a free-standing SEC led to a  
gauge factor that they used to map electrical signals to  
strain and thus, cracks. Time series measurements from  
the SECs and visual observations from crack growth were  
in agreement. Their sensing capability was further studied  
by deploying a sensor network of 20 SECs onto the  
surface of a full-scale post-tensioned concrete beam. A  
bending test with a loading and unloading sequence was  
conducted until structural failure, and data from the SECs  
and visual observation of cracks collected. Results  
demonstrated that data collected from the distributed SEC  
network correlated with crack-induced damage. The  
extraction of time series features, among which the  
maximum relative change in capacitance at each loading  
step, showed good agreement with the observed  
normalized crack length. Sensors 2019, 19, 1843 11 of 12  
Overall, the SEC network showed capable of detecting,  
localizing, and quantifying cracks in concrete.  
yet to invent or discover  
De Backer H, De Corte W, Van Bogaert P. (2003). A case study  
on strain gauge measurements on large post-tensioned  
concrete beams of a railway support structure. Insight-Non-  
Destructive Testing and Condition Monitoring. 45(12):822-  
Dilrukshi, K. and Dias, Priyan. (2016). Physical Modelling for  
Investigation Walls due to Thermal Movements of Cracking  
in Masonry of an Overlying Slab. Engineer: Journal of the  
Institution of Engineers, Sri Lanka. 43(1). DOI:  
Kaklauskas, Gintaris and Sokolov, Aleksandr and Ramanauskas,  
Regimantas and Jakubovskis, Ronaldas. (2019).  
Reinforcement Strains in Reinforced Concrete Tensile  
Members Recorded by Strain Gauges and FBG Sensors:  
Experimental and Numerical Analysis. Sensors. 19(1): 200.  
Kong X, Li J, Bennett C, Collins W, Laflamme S, Jo H. (2018).  
Large-scale strain sensing approach for detecting fatigue  
cracks in steel bridges. In9th International Conference on  
Bridge Maintenance, Safety and Management, IABMAS  
2018 (pp. 567-575). CRC Press/Balkema. DOI:  
Ranson WF, Vachon RI, Hovis GL, Nardiello JA, Fidnarick RD,  
Christ Jr RJ. (2007). Crack Detection and Monitoring Crack  
Growth in Fastener Holes using the DMI Optical SR-2  
Strain Measurement Technology. InASME International  
Mechanical Engineering Congress and Exposition, 43076:  
Cracks which are initiators for other problems can be  
determine in our infrastructure in many ways by using  
many technologies. So in this literature review, you can  
find out how we can have different technologies  
overcoming each other by the time. Cracks which are  
inbuild the concrete can be evaluate by strain gauge.  
Similarly, DMI technology, FBG strain gauge and SEC  
can also evaluate cracks’ abnormality. The literature  
reviewed in this case does not fully fill with the ideal  
Yan, Jin and Downey, Austin and Cancelli, Alessandro and  
Laflamme, Simon and Chen, An and Li, Jian and Ubertini,  
Filippo. Concrete Crack Detection and Monitoring Using a  
Capacitive Dense Sensor Array. Sensors. 19.  
Yan J, Downey A, Cancelli A, Laflamme S, Chen A, Li J,  
Ubertini F. (2019). Concrete crack detection and monitoring  
using a capacitive dense sensor array. Sensors. 19(8): 1843.