Identifying CFRP strip width influence on fracture of RC beams by acoustic emission

Tayfur, Sena; Alver, Ninel; Tanarslan, Hasan Murat; Ercan, Emre

doi:10.1016/j.conbuildmat.2018.01.189

Cited by 17 publications

(12 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Besides, this technique is actively applied to evaluate the condition of the structure which was affected by negative environmental factors (Tian and Han, 2016;Shields et al, 2018). Some studies use the combination of the X-ray CT with AE technique for quantitative estimation of concrete damage because AE generating behavior is closely associated with the formation process of microcracks in concrete (Ohtsu, 1987;Yamagishi and Suzuki, 2015;Suzuki and Shimamoto, 2017;Alver et al, 2017;Tayfur et al, 2018;Tayfur and Alver, 2019). The following works (Suzuki et al, 2010;Suzuki and Ohtsu, 2014;Karcili et al, 2016;Suzuki et al, 2020) include the specially developed method for quantitative damage evaluation which is based on estimating the intact modulus of elasticity of concrete.…”

Section: Introductionmentioning

confidence: 99%

Visualization and evaluation of concrete damage in-service headworks by X-ray CT and non-destructive inspection methods

Morozova

Shibano

Shimamoto

et al. 2022

Front. Built Environ.

Self Cite

View full text Add to dashboard Cite

The durability of concrete irrigation infrastructures decreases easily due to environmental effects, such as the freeze-thawed process. The degree of damage in concrete is, in most cases, evaluated by an unconfined compression test or ultrasonic test. The limiting states of structures are the result of a gradual accumulation of microdefects during the in-service period, which leads to the initiation and development of macroscopic cracks, loss of performance, and Failure. Therefore, to maintain such structures, it is necessary to properly determine the degree of damage by non-destructive testing. For effective maintenance and management of in-service structures, it is necessary to evaluate not only such mechanical properties as strength but also the degree of damage. Quantitative damage evaluation of concrete is proposed by applying the X-ray CT method and related non-destructive inspection, which is based on estimating cracking damage effects. In this study, the damage evaluation of concrete-core samples is investigated by X-ray CT parameters and the non-destructive parameters. The samples tested were taken from the damaged concrete headwork in Niigata, Japan, about 50 years after its construction. The geometric properties of the concrete matrix were calculated by the analysis of X-ray CT images. After X-ray CT measurement, an ultrasonic test and a resonant frequency test were performed. The dynamic modulus of elasticity was calculated by using ultrasonic pulse velocity and resonant frequency. As a result, based on the relationship between the geometric properties of the concrete matrix and the non-destructive parameters, the accumulation of damage in the samples tested was correlated with the ratio of the total area of cracks to the observation area. In damaged conditions, the high value of its ratio is demonstrated under low ultrasonic pulse velocity. These results suggest that the most sensitive components in a concrete body to the degree of damage are cracks in mortar and the ratio of the total area of cracks to the observation area. These values are affected by the internal actual cracks. Thus, the damage of concrete could be quantitatively evaluated by the geometric properties of the concrete matrix and its physical properties.

show abstract

Section: Introductionmentioning

confidence: 99%

Visualization and evaluation of concrete damage in-service headworks by X-ray CT and non-destructive inspection methods

Morozova

Shibano

Shimamoto

et al. 2022

Front. Built Environ.

Self Cite

View full text Add to dashboard Cite

show abstract

“…This is feasible due to the correlation between the AE waveform parameters and the crack tip displacement [2,7,8]. It is widely accepted that the tensile mode of fracture leads to higher frequencies and shorter signals than the shear mode in cementitious media [2,[9][10][11]. When displacement occurs in an elastic medium (i.e., crack propagation event), this disturbance propagates as an elastic wave (similar to ultrasound) through the medium.…”

Section: Introductionmentioning

confidence: 99%

“…Therefore, the RT (and consequently RA) tend to obtain higher values, while the total duration is also increased. This characteristic renders RT very indicative of the fracture mode [9,11,12,14,15]. The waveform parameters that appear mostly sensitive to the stress field and the crack tip displacement are presented in Figure 2 and are namely the rise time (RT) or delay between the onset and the highest waveform peak, and the RA value, defined as RT over maximum amplitude (A).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Acoustic Emission for Evaluating the Reinforcement Effectiveness in Steel Fiber Reinforced Concrete

et al. 2021

Self Cite

View full text Add to dashboard Cite

Steel fiber reinforcement in concrete strongly enhances its ductility and toughness. This is basically due to the additional fracture mechanisms and energy used to overcome the interlocking and adhesion between the fibers and the cementitious matrix. The enhancement of the final properties is measured by mechanical tests and can be assessed only at the end of loading. These processes can be targeted and monitored by acoustic emission (AE) indices offering real-time characterization of the material’s performance much earlier than the final failure or the termination of loading. In this study, steel fiber reinforced concrete (SFRC) beams were tested in bending with simultaneous AE monitoring. Tests conducted independently in different laboratories confirm that the AE behavior at low load levels is very indicative of the amount of reinforcement and consequently, of the final mechanical properties. The reason is that the reinforcement phase is activated through shear stresses in its interphase, a mechanism that is more profound in the presence of higher fiber content, and correspondingly is absent in plain unreinforced material. This finding opens the way to characterize the effectiveness of reinforcement with just a proof loading at less than 30% of the final load bearing capacity.

show abstract

“…Moreover, in domestic circumstances the 60-mm-wide CFRP strips are the most popular option for flexural strengthening. Larger width of the strips surely would affect the results [25,26]. The anchorage efficiency would be probably slightly lower for larger strips.…”

mentioning

confidence: 98%

Development of Bonded/Riveted Steel Anchorages of Prestressed CFRP Strips for Concrete Strengthening

et al. 2020

View full text Add to dashboard Cite

CFRP (carbon fiber reinforced polymer) strips are currently often used to strengthen reinforced concrete structures in flexure. In order to ensure effective strengthening, proper connection between FRP material and concrete structure is needed. CFRP strips can be applied passively (only by bonding to the concrete surface) or actively (by prestressing before bonding). In the case of passive strengthening, CFRP strips connecting by bonding to the surface along the strengthened element are usually sufficient. However, active (prestressing) CFRP strips should be additionally anchored at their ends. Anchoring of unidirectional CFRP strips to the reinforced concrete is difficult because of their weak properties in transverse directions. The paper presents a development of mechanical steel anchorages used in an active CFRP flexural strengthening system for reinforced concrete structures. The anchorages were made of steel plates connected to CFRP strips with steel rivets and epoxy adhesive. They were developed within series of tests on specimens from small-scale to full-scale tested in an axial tensile scheme. The paper describes successive modifications of the anchorages as well as the results of full-scale tests. The final version of the anchorage developed during the research had a tensile failure force of 185 kN, which is sufficient value for CFRP strengthening purposes.

show abstract

Identifying CFRP strip width influence on fracture of RC beams by acoustic emission

Cited by 17 publications

References 24 publications

Visualization and evaluation of concrete damage in-service headworks by X-ray CT and non-destructive inspection methods

Visualization and evaluation of concrete damage in-service headworks by X-ray CT and non-destructive inspection methods

Acoustic Emission for Evaluating the Reinforcement Effectiveness in Steel Fiber Reinforced Concrete

Development of Bonded/Riveted Steel Anchorages of Prestressed CFRP Strips for Concrete Strengthening

Contact Info

Product

Resources

About