Influence of nano materials in the distressed retaining structure for crack filling

Nirmala, J.; Dhanalakshmi, G.

doi:10.1016/j.conbuildmat.2015.04.022

Cited by 6 publications

(4 citation statements)

References 12 publications

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“…According to Darcy's law and the mass conservation equation, the difference between the inflow and outflow of fluid at a certain point of an element within a certain time period equals the change in the volumetric water content of the soil. The differential equations for two-dimensional seepage can be expressed as [49]:…”

Section: The Seepage Equation Of Unsaturated Soilmentioning

confidence: 99%

Investigating Deformation Mechanism of Earth-Rock Dams with InSaR and Numerical Simulation: Application to Liuduzhai Reservoir Dam, China

Liu,

Hu,

Liu

et al. 2023

Remote Sensing

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Ground deformation is the direct manifestation of the earth-rock dam's hazard potential. Therefore, it is essential to monitor deformation for dam warning and security evaluation. The Liuduzhai Dam, a clay-core dam of a large reservoir in China, was reinforced with plastic concrete cut-off walls between 13 January 2009 and 29 May 2010, as it was subject to leakage and deformation. However, the deformation development and the mechanism of the dam are still unclear. In this study, the deformation fields before and after the reinforcement of the Liuduzhai Dam were yielded by using the Interferometric Synthetic Aperture Radar (InSAR) technique. Furthermore, a numerical simulation method was employed to obtain the dynamic seepage field of the dam during the InSAR observation period. The results indicated that the average deformation velocity and maximum deformation velocity are −11.7 mm/yr and −22.5 mm/yr, respectively, and the cumulative displacement exceeds 100 mm, which shows typical continuous growth characteristics in a time series. In contrast, the dam deformation tended to be stable after reinforcement, with the average deformation velocity and maximum deformation velocity being −0.4 mm/yr and −1.2 mm/yr, respectively, behaving as cyclical deformation time series. According to the results of InSAR and seepage analysis, it is shown that: (1) dynamic seepage was the main mechanism controlling dam deformation prior to reinforcement; (2) the concentrated load caused by construction and the rapid dissipation of pore water pressure caused by the sudden drop of the infiltration line were the reasons for the acceleration of deformation during and after construction; and (3) the plastic concrete cut-off walls effectively reduced the dynamic seepage field, while the water level fluctuations were the main driving factor of elastic deformation of the dam after reinforcement. This study provides a novel approach to investigating the deformation mechanism of earth-rock dams. Furthermore, it has been confirmed that InSAR can identify the seepage deformation of dams by detecting surface movements. It is recommended that InSAR deformation monitoring should be incorporated into future dam safety programs to provide detailed deformation signals. By analyzing the temporal and spatial characteristics of the deformation signal, we can identify areas where dam performance has degraded. This crucial information aids in conducting a comprehensive dam safety assessment.

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Section: The Seepage Equation Of Unsaturated Soilmentioning

confidence: 99%

Investigating Deformation Mechanism of Earth-Rock Dams with InSaR and Numerical Simulation: Application to Liuduzhai Reservoir Dam, China

Liu,

Hu,

Liu

et al. 2023

Remote Sensing

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“…The oxygen-containing functional groups make the GO-dispersion hydrophilic and dispersive (Dreyer et al, 2014), which can help forming hydration products. These make hydration products interweave and penetrate into a uniform and dense microstructure (Raki et al, 2010;Amin and Abu el-Hassan, 2015;Nirmala and Dhanalakshmi, 2015), resulting in microcosmic defect reductions (Zhao et al, 2020), and thus significantly improve the strength, toughness, and durability of cement composites (Peng et al, 2019). Lv et al (2013) investigated the effect of GO nanosheets on the microstructure and mechanical properties of cement composites.…”

Section: Introductionmentioning

confidence: 99%

Mechanical and fatigue properties of graphene oxide concrete subjected to sulfate corrosion

Wang,

Zhang,

Liu

et al. 2023

Front. Mater.

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Concrete structures usually have to experience some unfavorable environmental actions during their service life, leading to the mechanical properties degradation, moreover, cyclic loadings such as traffic loads, wind loads may further accelerate structural damage, therefore, improving durability of concrete is of vital for structures servicing in severe environment. Graphene oxide (GO), as a new nano-reinforced material, has ultra-high mechanical properties and large specific surface area as a concrete reinforcing material. This study entailed an examination of the properties of Graphene Oxide Concrete (GOC) with varying levels of GO incorporation (0, 0.02, 0.05, 0.08 wt%). It also encompassed an analysis of the fatigue properties of GOC under different stress levels and varying sulfate wetting and drying cycles. Additionally, the investigation delved into the degradation mechanisms affecting Graphene Oxide Concrete (GOC) when subjected to sulfate erosion conditions. Furthermore, the study assessed the mass loss of specimens and their fatigue life under diverse environmental conditions. The results showed that appropriate GO incorporations could enhance concrete’s mechanical and fatigue properties after sulfate attack. In addition, scanning electron microscope (SEM) analysis showed that GO could adjust the aggregation state of cement hydration products and its own reaction with some cement hydration crystals to form strong covalent bonds, to improve and enhance microstructural denseness.

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“…With the rise of nanotechnology, the application of nanomaterials in cement-based materials for improving properties has become a new research hotspot in recent years [ 17 ]. Nanomaterials can fill the voids in cement-based materials and form tighter interfaces between aggregates and cementitious components, which is beneficial to the improvement of mechanical properties and durability [ 18 , 19 , 20 ]. Nano silica (NS) with a large surface area can increase the pozzolanic activity by acting as a center for crystallization, resulting in the formation of large idiomorphic crystals of Ca-Si composition, thus leading to denser microstructure with reduced porosity and increased mechanical strength [ 21 , 22 , 23 ].…”

Section: Introductionmentioning

confidence: 99%

Cement-Based Materials Containing Graphene Oxide and Polyvinyl Alcohol Fiber: Mechanical Properties, Durability, and Microstructure

Jiang

et al. 2018

Nanomaterials

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The influence of graphene oxide (GO) and polyvinyl alcohol (PVA) fiber on the mechanical performance, durability, and microstructure of cement-based materials was investigated in this study. The results revealed that compared with a control sample, the mechanical strength and durability of cement-based materials were significantly improved by adding PVA fiber and GO. The compressive and flexural strength at 28 d were increased by 30.2% and 39.3%, respectively. The chloride migration coefficient at 28 d was reduced from 7.3 × 10−12 m2/s to 4.3 × 10−12 m2/s. Under a sulfate corrosion condition for 135 d, the compressive and flexural strength still showed a 13.9% and 12.3% gain, respectively. Furthermore, from the Mercury Intrusion Porosimetry (MIP) test, with the incorporation of GO, the cumulative porosity decreased from more than 0.13 cm3/g to about 0.03 cm3/g, and the proportion of large capillary pores reduced from around 80% to 30% and that of medium capillary pores increased from approximately 20% to 50%. Scanning electron microscope (SEM) images showed a significant amount of hydration products adhering to the surface of PVA fiber in the GO and PVA fiber modified sample. The addition of GO coupling with PVA fiber in cement-based materials could promote hydration of cement, refine the microstructure, and significantly improve mechanical strength and durability.

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Influence of nano materials in the distressed retaining structure for crack filling

Cited by 6 publications

References 12 publications

Investigating Deformation Mechanism of Earth-Rock Dams with InSaR and Numerical Simulation: Application to Liuduzhai Reservoir Dam, China

Investigating Deformation Mechanism of Earth-Rock Dams with InSaR and Numerical Simulation: Application to Liuduzhai Reservoir Dam, China

Mechanical and fatigue properties of graphene oxide concrete subjected to sulfate corrosion

Cement-Based Materials Containing Graphene Oxide and Polyvinyl Alcohol Fiber: Mechanical Properties, Durability, and Microstructure

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