Monitoring the Self-healing of Concrete from the Ultrasonic Pulse Velocity

Camara, Letícia; Wons, Mayara; Esteves, Ian C.A.; Medeiros-Junior, Ronaldo A.

doi:10.3390/jcs3010016

Cited by 30 publications

(15 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In general, the ultrasonic techniques used for material characterization differ in how the wave is induced, its type and properties, the phenomena accompanying the propagation of waves in the material (such as reflection, scattering, or absorption by material particles), and the equipment used. In the field of research on the properties of cement-based composites, including self-healing or self-sealing, techniques based on ultrasonic pulse velocity (UPV) [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ], acoustic emission [ 26 , 27 , 28 ], surface-wave transmission [ 29 ], diffuse ultrasound [ 30 ], or coda wave interferometry are used [ 31 ].…”

Section: Introductionmentioning

confidence: 99%

“…In this respect, the three types of UPV tests are direct transmission (cross probing), semi-direct transmission, and indirect transmission (surface probing) [ 19 ]. Camara et al [ 20 ] used UPV tests in cylindrical concrete samples in which defects were induced by compressive stress and subsequent self-healing under conditions of cyclic immersion in a lime-saturated solution and drying at 22 ± 3 °C, a relative humidity of 75.4% ± 6.6%, and a carbon dioxide concentration of 0.75% ± 0.13%. Zhong and Yao [ 21 ] used ultrasonic techniques in combination with mechanical tests to prove that a certain threshold of material damage degree exists, below which the ability of concrete to self-heal increases with the degree of damage and above which this ability decreases with the degree of damage.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Self-Sealing Process Evaluation Method Using Ultrasound Technique in Cement Composites with Mineral Additives

2020

View full text Add to dashboard Cite

The self-sealing process, associated with chemical and microstructural changes inside damaged cement-based composites, leads to the recovery of the original material integrity. Assessing the magnitude of internal changes in samples using non-destructive techniques to capture only the self-sealing effects is difficult. The challenge is evaluating the differences between subsequent observations in time and between samples with different properties. This paper proposes a new approach to the use of an ultrasonic technique for self-sealing investigation. The method allows the quantification of material changes strictly related to self-sealing processes, excluding changes caused by the naturally progressing hydration of binders. The applied ultrasonic pulse velocity (UPV) data processing procedure allows the investigation of material changes inside and near the cracks, the effects of stimulating the self-sealing of cement composites with mineral additives, and the assessment of changes over time. An important aspect of the method is the sample preparation procedure and testing conditions that reduce the impact of moisture content on the UPV measurements. New parameters allowing the quantitative characterization of the self-sealing process are proposed. The method was evaluated using cement mortars modified with siliceous fly ash with induced cracks 0 to 750 µm wide, which were then cured in water for 152 days. The maximum degree of effective crack filling as a result of autogenous self-sealing in the tested mortars was determined to range from 33% to 57%. Observations of the microstructure of the crack surface confirmed that apart from the volume of the newly formed products, the density of these products may have a key impact on the ultrasonic measurements of the self-sealing performance. The studies were supplemented by the examination of the compression strength of mortars, mortar sample scanning and computer image processing, and observations using an optical microscope and scanning electron microscope with energy dispersive spectroscopy.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Self-Sealing Process Evaluation Method Using Ultrasound Technique in Cement Composites with Mineral Additives

2020

View full text Add to dashboard Cite

show abstract

“…The tests most used to assess the ISA are length change and mechanical strength monitoring. However, non-destructive testing can be used as an alternative tool [13,14]. Genoves et al [13] evaluated the use of dynamic modulus of elasticity through resonance frequency and ultrasonic pulse velocity in the ISA evaluation.…”

Section: Introductionmentioning

confidence: 99%

Mitigation potential of sulfate-resistant Portland cement for internal sulfate attack

2021

Self Cite

View full text Add to dashboard Cite

Concrete structures can have their durability affected due to internal sulfate attack (ISA). This attack can occur by the use of aggregates contaminated with sulfides, such as pyrite. The oxidation of pyrite releases sulfate ions into the cement matrix and favors the formation of expansive phases, such as gypsum and secondary ettringite. These expansions cause cracks and progressive degradation of concrete structures. Therefore, this study aimed to evaluate the effect of sulfate-resistant Portland cement in the likely mitigation of ISA. Mortar specimens with two types of cement (CEM I and CEM I SR) were cast with and without pyrite. These mortars naturally aged for 406 days and later were subjected to wetting and drying cycles at 40 °C to stimulate the ISA. The following properties of mortars were evaluated over time: length change and mass variation, tensile and compressive strengths, capillary and immersion water absorption, and electrical resistivity. The results showed that sulfate-resistant Portland cement only managed to reduce the length change in the first ages. The results of water absorption tests showed that the attack by sulfates due to pyrite oxidation is in the early stages. However, water absorption was reduced by 60% during the 56 wetting and drying cycles with water only. The electrical resistivity of the pyrite mortars was greatly affected (about 550%) over the 18 weeks of exposure.

show abstract

“…The restless search for durability and resilience of concrete structures has led some researchers to focus on self-healing concrete composites with the built-in ability of repairing narrow cracks without human or external intervention [ 2 , 3 , 4 , 5 ]. Two major types of self-healing concretes have emerged: the autogenous type [ 4 ], which is achieved by autogenous healing materials such as mineral admixtures like ground-granulated blast-furnace slag (GGBFS), silica fume or fly ash, fibers and nanofillers [ 6 , 7 , 8 , 9 , 10 , 11 , 12 ]; and, the autonomous type [ 3 ], which is realized by unconventional engineered additions such as shape memory alloys, capsules, polymers or bacteria to seal the cracks [ 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 ]. Autogenous healing is an old and well-known phenomenon that originates naturally from the cementitious material like the hydration of clinker minerals or the carbonation of calcium hydroxide while autonomous healing requires a trigger to activate the process.…”

Section: Introductionmentioning

confidence: 99%

Effect of Clinker Binder and Aggregates on Autogenous Healing in Post-Crack Flexural Behavior of Concrete Members

et al. 2020

View full text Add to dashboard Cite

Crack healing has been studied extensively to protect reinforced concrete structures from the ingress of harmful ions. Research examining the regain in the mechanical properties of self-healing composites has focused mostly on the computation of the healing ratio based on the measurement of the tensile and compressive strengths but with poor regard for the flexural performance. However, the regain in the flexural performance should also be investigated for design purposes. The present study performs flexural testing on reinforced concrete members using crushed clinker binder and aggregates as well as crystalline admixtures as healing agents. Healing ratios of 100% for crack widths smaller than 200 μm and 85% to 90% for crack widths of 250 μm were observed according to the admixing of clinker binder and aggregates. Water flow test showed that the members replacing binder by 100% of clinker achieved the best crack healing performance. The crack healing property of concrete improved to some extent the rebar yield load, the members’ ultimate load and energy absorption capacity and ductility index. The crack distribution density from the observed crack patterns confirmed the crack healing effect provided by clinker powder. The fine grain size of clinker made it possible to replace fine aggregates and longer healing time increased the crack healing effect.

show abstract

Monitoring the Self-healing of Concrete from the Ultrasonic Pulse Velocity

Cited by 30 publications

References 17 publications

Self-Sealing Process Evaluation Method Using Ultrasound Technique in Cement Composites with Mineral Additives

Self-Sealing Process Evaluation Method Using Ultrasound Technique in Cement Composites with Mineral Additives

Mitigation potential of sulfate-resistant Portland cement for internal sulfate attack

Effect of Clinker Binder and Aggregates on Autogenous Healing in Post-Crack Flexural Behavior of Concrete Members

Contact Info

Product

Resources

About