Visualized tracing of crack self-healing features in cement/microcapsule system with X-ray microcomputed tomography

Fang, Guohao; Liu, Yuqing; Qin, Shaofeng; Ding, Weijian; Zhang, Jianchao; Hong, Shuxian; Xing, Feng; Dong, Biqin

doi:10.1016/j.conbuildmat.2018.05.193

Cited by 39 publications

(13 citation statements)

References 53 publications

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“…The development of CPs and the possible formation of corrosion-induced cracks can be monitored with scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS), X-ray diffraction (XRD), Raman spectroscopy and X-ray μCT (Fig. 7) [128,[254][255][256][257][258]. Four different parts can be observed in the material: the steel, the dense product layer, the transformed medium and the binder [259,260].…”

Section: Impact On the Structural Performance Of Rc Structuresmentioning

confidence: 99%

Reinforced concrete structures: A review of corrosion mechanisms and advances in electrical methods for corrosion monitoring

Rodrigues

Gaboreau

Gance

et al. 2021

Construction and Building Materials

182

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Steel corrosion is the main cause of deterioration of reinforced concrete (RC) structures. We provide an up-to-date review on corrosion mechanisms and recent advances in electrical methods for corrosion monitoring. When assessing corrosion mechanism, the inherent heterogeneity of RC structures and the significant effect of environmental factors remain major issues in data interpretations. The steel surface condition and local inhomogeneities at the steel-concrete interface appear to have an important effect on corrosion initiation. Considering uniform corrosion in atmospherically exposed reinforced concrete, the two main influencing factors of the corrosion process are the water content and the pore structure at the steel-concrete interface. However, irrespective of the depassivation mechanism, i.e. carbonation or chloride-induced corrosion, nonuniform corrosion is expected to be the main process for RC structures due to local variations in environmental exposure or the presence of interconnected rebars with different properties. Future studies may then be focused on their effect on macrocell corrosion to gain further insights in the corrosion mechanisms of RC structures. Concerning corrosion monitoring using electrical methods, the half-cell potential technique with potential mapping is accurate for locating areas with a high corrosion risk. Recent developments in the measurement of concrete resistivity have shown that the use of electrical resistivity tomography allows to consider appropriately the inherent heterogeneity of concrete and provides more insights on transport phenomena (e.g. water and salts ingress) in the material. Nevertheless, during the corrosion propagation stage, the polarization resistance remains the most important parameter to be determined as it provides quantitative information of the corrosion rate. If conventional three-electrode configuration methods can supply an accurate determination in the case of uniform corrosion, they often fail in the case of macrocell corrosion in field experiments. Recent advances have shown that a four-electrode configuration without any connection to the rebar can rather be used for the non-destructive testing and evaluation of corrosion. If studies are still required to quantify the corrosion rate, this method appears sensitive to localized corrosion and thus more suitable to field investigations. Finally, the coupling of numerical simulations with complementary electrical and other non-destructive testing methods is essential for consolidating the results to provide a better diagnosis of the service life of RC structures.

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Section: Impact On the Structural Performance Of Rc Structuresmentioning

confidence: 99%

Reinforced concrete structures: A review of corrosion mechanisms and advances in electrical methods for corrosion monitoring

Rodrigues

Gaboreau

Gance

et al. 2021

Construction and Building Materials

182

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“…Concrete is the most widely used construction material in the world [1]. However, normal concrete is inherently brittle when subjected to static (including tensile and flexural) and high-velocity dynamic loadings, and is susceptible to cracking induced by unsuitable curing conditions, freeze-thawing and shrinkage [2,3,4,5]. As a result, normal concrete exhibits a brittle failure pattern under dynamic impact loadings, posing a serious threat to the integrity and safety of concrete infrastructure in highly seismic (e.g., earthquake) or marine zones (e.g., wave impact and wind load).…”

Section: Introductionmentioning

confidence: 99%

Effects of Polypropylene Fibre and Strain Rate on Dynamic Compressive Behaviour of Concrete

et al. 2019

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This paper presents an experimental study on the dynamic compressive behaviour of polypropylene (PP) fibre reinforced concrete under various strain rates using split Hopkinson pressure bar (SHPB) equipment. The effects of PP fibre content and strain rate on the dynamic compressive stress-strain relationship and failure patterns were estimated. The results indicated that the addition of PP fibre enhanced the dynamic compressive properties of concrete mixtures although it resulted in a significant reduction in workability and a slight decrease in static compressive strength. Considering the workability, static compressive strength and dynamic compressive behaviour, the optimal PP fibre content was found to be 0.9 kg/m3 as the mixture exhibited the highest increase in dynamic compressive strength of 5.6%, 40.3% in fracture energy absorption and 11.1% in total energy absorption; further, it showed the least reduction (only 5.8%) in static compressive strength among all mixtures compared to the reference mixture without fibre. For all mixtures, the dynamic compressive properties, energy absorption capacity, strain at peak stress, ultimate strain and dynamic increase factor (DIF) were significantly influenced by strain rate, i.e., strain rate effect. When the strain rate was relatively low, PP fibres were effective in controlling the cracking, and the dynamic compressive properties of PP fibre reinforced mixtures were improved accordingly.

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“…The performance of healing cracks can be enhanced by various parameters viz: biological agents [15][16][17][18][19][20][21], chemical agents [22], encapsulated capsules [23][24][25][26][27] and pozolonic materials [28]. There is an improvement in lifetime of concrete structure by crack healing.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Mechanical Parameters of Bacterial Concrete

Durga¹,

Nerella²,

Madduru³

et al. 2019

ACSM

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Conventional concrete is prone to cracking under tensile load, despite its good compressive strength. Recently, biological agents have been applied to heal the cracks in concrete, making concrete structures more serviceable. This paper mainly attempts to evaluate the mechanical properties of bacteria-based self-healing concrete. Two bacteria were selected as the bioagents in concrete, namely, Bacillus subtilis and Bacillus halodurans. The concentration of the bioagents were set to 10 5~1 0 7 cell/mL in water. Then, the two bacteria were applied to cracked concrete to cure the cracks. After curing for several days, the bacteria-based self-healing concrete was subjected to compressive and flexural tests to estimate its mechanical parameters. The results show that the self-healing concretes cured for 14d and 28d had a 7% and 18% higher compressive strength than conventional concrete, respectively; the self-healing concretes cured for 14d and 28d had a 11% and 28% higher flexural strength than the conventional concrete, respectively. Thus, the bioagents could effectively heal the surface cracks on concrete, and make the concrete imperviable.

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Visualized tracing of crack self-healing features in cement/microcapsule system with X-ray microcomputed tomography

Cited by 39 publications

References 53 publications

Reinforced concrete structures: A review of corrosion mechanisms and advances in electrical methods for corrosion monitoring

Reinforced concrete structures: A review of corrosion mechanisms and advances in electrical methods for corrosion monitoring

Effects of Polypropylene Fibre and Strain Rate on Dynamic Compressive Behaviour of Concrete

Evaluation of Mechanical Parameters of Bacterial Concrete

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