Dr. Sumit Gandhi - Academia.edu (original) (raw)
Papers by Dr. Sumit Gandhi
Zenodo (CERN European Organization for Nuclear Research), Apr 1, 2014
The effect of an abruptly expanding channel on the main characteristics of hydraulic jump is cons... more The effect of an abruptly expanding channel on the main characteristics of hydraulic jump is considered experimentally. The present study was made for supercritical flow of Froude number varying between 2 to 9 and approach to expanded channel width ratios 0.4, 0.5, 0.6 and 0.8. Physical explanations of the variation of these characteristics under varying flow conditions are discussed based on the observation drawn from experimental results. The analytical equation for the sequent depth ratio in an abruptly expanding channel as given by eminent hydraulic engineers are verified well with the experimental data for all expansion ratios, and the empirical relation was also verified with the present experimental data.
Portugaliae Electrochimica Acta, 2020
A comparative study of the corrosion behavior of pure magnesium and AZ91D anodes in reinforced ce... more A comparative study of the corrosion behavior of pure magnesium and AZ91D anodes in reinforced cement concrete was undertaken in the present work. The steel reinforcements were electrochemically kept in contact with these anodes in a chloride atmosphere, and the half-cell potential drop was observed. Bare steel reinforcements were tied to the anodes and were also kept in a high chloride atmosphere to test the mechanical properties. The yield stress and ultimate tensile stress were found to decrease by approximately 50 MPa, while the reduction in percentage elongation was approximately 25% for reinforcements tied to AZ91D and pure Mg, at the end of 80 days, compared to the fresh steel reinforcement. The rate of corrosion of pure Mg was reportedly slightly higher compared to AZ91D, due to the presence of inter-metallics, as inferred through micro-graphs.
International Journal of Mechanical Engineering
The transport of fluids through pipes is very common in core engineering practice. The main issue... more The transport of fluids through pipes is very common in core engineering practice. The main issue that came up when the pipe flow networks were its analysis part. The Hardy Cross approach is very accurate and reliable for solving these issues, but because it is iterative, the likelihood of errors increases as the number of circuit loops grows. Therefore, in this research, a piece of effort has been made to automate the Hardy Cross technique using Python programming (as it is userfriendly and has a large library backup) to remove the errors that come with using hand calculations. The built program has been applied to four different pipe flow network problems, and the outcomes are the same as those presented in the literature.
Emerging Materials Research
In this research, the benefits of nano-titanium dioxide (nano-TiO2) concrete over pure concrete i... more In this research, the benefits of nano-titanium dioxide (nano-TiO2) concrete over pure concrete in resisting the impacts of chloride diffusion were investigated. An increasing accelerative effect of chloride diffusion was experimentally discovered, which coincided with the movement in the exposed concrete surface caused by diffusion and the damage in concrete microstructure caused by chloride salt accumulation. The ‘time lag’ and ‘equivalent time’ between diffusion and migration tests were used to calculate the steady- and non-steady-state chloride diffusion coefficients. Concrete containing 2% nano-titanium dioxide by weight of cement demonstrated improved impermeability when compared with pure concrete, owing to improvements in microstructure and porosity. In comparison with pure concrete, the concrete containing nano-titanium dioxide had superior performance in resisting the effects of chloride diffusion. Because of its superfine particle size distribution and ‘filler’ effect, na...
Asian Journal of Civil Engineering
The current paper experimentally investigates the effects of partial replacement of cement by nan... more The current paper experimentally investigates the effects of partial replacement of cement by nano-TiO 2 (NT) in concrete in varying proportions by weight. NT was added by weight of cement with partial replacement of 0%, 0.5%, 1.5%, 2.0%, 2.5%, and 3.0% using Portland Pozzolana Cement in C20/25 grade of concrete. The physical and mechanical properties of concrete so produced were evaluated and durability aspects such as slump, sorptivity, half-cell potential, and drying shrinkage were also conducted. The fresh concrete produced showed a drastic reduction of the slump with increasing percentage replacement with 74% reduction at 3.0% replacement compared to the control mix. Further, the 7, 28, 56, and 90 days compressive, flexural, and split tensile strength showed a peak at 1.5% NT after which the values dropped in strength by 34.5%, 27%, and 19% concerning the control mix for 2.0%, 2.5%, and 3.0% replacement levels, respectively. From the microstructural studies, it could be concluded that nano-TiO 2 acts as a filler material and can be used as a partial replacement for cement effectively up to 3% of the weight of cement in concrete. Thus, incorporating nanoparticles could cause more strength and resistance to water permeability of the specimens.
The Asian Review of Civil Engineering
In this research article an attempt has been made to analyse the design wind pressure on the rect... more In this research article an attempt has been made to analyse the design wind pressure on the rectangular buildings using Python programming. For this purpose, design wind pressure is calculated and compared using IS 875 (Part 3) 1987 and the revised code IS 875 (Part 3) 2015. The concept have been applied to three different building heights i.e. 20, 40, and 60 m having same plan 1010 m2. It has been observed that the impact of wind pressure on the building rises with the building height along with the fact that the design wind pressures obtained from revised code show more pressures in comparison to the old one. Therefore, the design based on the revised code will be more close to the reality as it incorporates risk factor, directionality factor, area averaging factor, and combination factors. Also, the module developed for wind loads can be readily used by the researchers/designers for the better understanding of programming and the design loads.
ACI Materials Journal
The current paper investigates the effects of partial cement replacement with nano-titanium dioxi... more The current paper investigates the effects of partial cement replacement with nano-titanium dioxide (nano-TiO 2 [NT]) in varying weight proportions in concrete. In the C20/25 grade of concrete, NT was added by weight of cement with partial replacement of 0, 0.5, 1.5, 2.0, 2.5, and 3.0% using portland pozzolana cement. The physical and mechanical properties of the resulting concrete were assessed, as well as aspects of durability such as sorptivity and nondestructive tests (NDT) such as ultrasonic pulse velocity (UPV). Compared with the control mixture, the fresh concrete produced showed a drastic reduction in slump with increasing percentage of replacement, with a 54% reduction at a 3.0% replacement. Furthermore, for 1.5% NT, the compressive, flexural, and splitting tensile strengths peaked at 7, 28, 56, and 90 days, after which the values decreased. The addition of NT improved the homogeneity and integrity of the resulting concrete based on the UPV values. As the percentage of NT increased, chloride penetration decreased. From microstructural studies, it can be concluded that NT acts as a filler material and can be used as a partial replacement for cement in concrete up to 2% by weight.
The effect of an abruptly expanding channel on the main characteristics of hydraulic jump is cons... more The effect of an abruptly expanding channel on the main characteristics of hydraulic jump is considered experimentally. The present study was made for supercritical flow of Froude number varying between 2 to 9 and approach to expanded channel width ratios 0.4, 0.5, 0.6 and 0.8. Physical explanations of the variation of these characteristics under varying flow conditions are discussed based on the observation drawn from experimental results. The analytical equation for the sequent depth ratio in an abruptly expanding channel as given by eminent hydraulic engineers are verified well with the experimental data for all expansion ratios, and the empirical relation was also verified with the present experimental data.
Corrosion of reinforcements in reinforced cement concrete structures is an active area of researc... more Corrosion of reinforcements in reinforced cement concrete structures is an active area of research in civil engineering. One of the method of corrosion prevention being cathodic or sacreficial protection. The current work investigates the effect of using pure Mg and AZ91D as sacrificial anodes in ordinary and marine atmosphere on concrete slabs containing partial replacements of cement and fine aggregates by sugar cane bagasse ash (SCBA) and mill scale (MS) respectively by half cell potential (HCP) studies for 270 days. Twelve slabs were casted with centrally placed anodes, tied with the reinforcement cage and HCP readings were observed for 280 days at different locations of the slabs. Slabs were casted without and with 3.5 wt% NaCl. It is observed that at the end of 280 days the slab without any replacement and containing 3.5 wt% NaCl showed maximum values of HCP, whereas, the slabs containing MS or SCBA without any Cl content, showed least HCP values. This is because both MS and S...
Hydraulic jump is most frequently encountered features of RVF in open channels as the supercritic... more Hydraulic jump is most frequently encountered features of RVF in open channels as the supercritical flow changes to subcritical flow; during this phenomenon air is entrained because of the breaking of number of wavelets on the surface and get released in the form of air bubbles. Compared to prismatic, non-prismatic channels with appurtenances not only modify the hydraulic jump characteristics but also affect significantly the formation of symmetric flows downstream of the channel. Moreover, non-prismatic channels with baffle blocks & sill arrangements are useful to control the hydraulic jump in stilling basins when there is deficiency of tail water depth and the places where there is design constraints in order to reduce the basin length. It is also useful in the situations where it is impossible to depress the basin floor because of difficulties in excavation; a lateral expansion remains the only option for the required dissipation of energy through formation of hydraulic jump. For...
Present study deals with the bed load transport and shear stress with uniform and nonuniform sedi... more Present study deals with the bed load transport and shear stress with uniform and nonuniform sediments in an open channel under different experimental conditions. Effort has been made to analyse extensive experimental results in comparison with the existing theories given by the various eminent researchers for both the types of sediment materials. Empirical relations are proposed by dimensionless approach with the help of Buckingham-π theorem in terms of dimensionless shear stress and bed load transport parameter. Results are compared and vaidated with Meunier (2006) and Roorkee‟s approach [i.e. Gilbert (1914), Pazis & Graf, Paintal (1977), Misri et. al (1984), Ranga Raju & R. J. Garde (1986)] for both uniform and non uniform sediment material. © 2016 Elixir all rights reserved. Elixir Civil Engg. 91 (2016) 38310-38314 Civil Engineering Available online at www.elixirpublishers.com (Elixir International Journal) Sumit Gandhi et al./ Elixir Civil Engg. 91 (2016) 38310-38314 38311 only...
IOP Conference Series: Earth and Environmental Science, 2021
The use of agricultural wastes rich in pozzolanic materials such as Fe2O3, SiO2 and Al2O3 is an a... more The use of agricultural wastes rich in pozzolanic materials such as Fe2O3, SiO2 and Al2O3 is an active area of research in concrete technology. This improves the mechanical and durability properties along with sustainability. One such waste is the Sugar Cane Bagasse Ash (SCBA) generated by sugar mills and usually dumped in open space. The main purpose of the study is to investigate synergic effect of cathodic protection and using SCBA blended cement concrete on the corrosion resistance of embedded reinforcement and compare it with control concrete. The approach involved construction of eight slabs (1 m X 0.1 m X 0.1 m) and monitoring the half cell potential (HCP) for 270 days. In order to simulate the marine atmosphere, two slabs were constructed with 3.5% NaCl by weight of cement and two others were reference slabs. The pure Magnesium anodes 22 mm diameter and 250 mm long were used. The experimental results indicated that the corrosion of embedded reinforcement in slab containing S...
Civil Engineering Journal, 2018
Comparative study of the corrosion behavior of pure Magnesium and AZ91D anodes in reinforced ceme... more Comparative study of the corrosion behavior of pure Magnesium and AZ91D anodes in reinforced cement concrete was undertaken in the present work. The steel reinforcements were kept in contact with these anodes electrochemically in chloride atmosphere and the half-cell potential drop was observed. Bare steel reinforcements were tied to the anodes and were also kept in high chloride atmosphere to test the mechanical properties. The yield stress and ultimate tensile stress were found to decrease by approximately 50MPa while the reduction in percentage elongation is approximately 25% for reinforcements tied to AZ91D and pure Mg at the end of 80 days compared to fresh steel reinforcement. The rate of corrosion of pure Mg was reportedly slightly higher compared to AZ91D due to the presence of inter-metallics as inferred through micro-graphs.
IOP Conference Series: Materials Science and Engineering, 2018
The current work investigates the performance of pure Magnesium on corrosion prevention of steel ... more The current work investigates the performance of pure Magnesium on corrosion prevention of steel reinforcements by way of sacrificial anoding. Two set of six steel reinforcements were tested for half-cell potential, weight loss, anode efficiency and tensile strength for each of the sacrificial anodes in a high chloride atmosphere of 7.5% NaCl in tap water. Significant reduction in weight of anode was observed during the initial 12 days. The reduction in weight of steel reinforcements tied with anodes was found to be negligible, while that of reinforcements without anodes was significantly higher. Five distinct zones of corrosion were observed during the test. The tensile strength of steel cathodically protected by Mg alloy anodes was found less affected. It could be concluded that pure Mg anode provides an effective way of corrosion mitigation.
International journal of physical sciences
ABSTRACT
International Journal of Fluid Mechanics Research, 2014
Journal of The Institution of Engineers (India): Series A, 2016
Empirical relations for hydraulic jump characteristics, viz. sequent depth ratio (Y 2 /Y 1), effi... more Empirical relations for hydraulic jump characteristics, viz. sequent depth ratio (Y 2 /Y 1), efficiency of jump (E 2 /E 1) and relative length of jump (L j /Y 1) in trapezoidal channel with/without appurtenances are developed by introducing dimensionless Reynolds number, and neglecting the frictional effect for approach Froude number (varied between 2 and 10 under different conditions). Developed empirical models were also validated and compared with acquired experimental data as well as with literature data. Close fitness of the empirical models with appurtenances under varying dimensions, positions of baffle blocks provides accurate prediction of same for higher value of Froude number. Keywords Trapezoidal channel Á Hydraulic jump Á Energy dissipation Á Reynolds number Á Baffles q Density of water, Kg/m 3 l Dynamic viscosity of water, Ns/m 2 e Surface roughness, m h Side slope angle
Empirical relations for hydraulic jump characteristics, viz. sequent depth ratio (Y 2 /Y 1), effi... more Empirical relations for hydraulic jump characteristics, viz. sequent depth ratio (Y 2 /Y 1), efficiency of jump (E 2 /E 1) and relative length of jump (L j /Y 1) in non-prismatic channel (i.e., suddenly expanding) with/without appurtenances are developed by introducing dimensionless Reynolds number, and neglecting the frictional effect for approach Froude numbers between 2 to 9 under different channel conditions. Developed empirical models were also tested, validated and compared with acquired experimental data as well as with literature data. Close fitness of the empirical models with appurtenances under varying dimensions, positions of baffle blocks and end sill provides accurate prediction of same for higher value of Froude number.
Zenodo (CERN European Organization for Nuclear Research), Apr 1, 2014
The effect of an abruptly expanding channel on the main characteristics of hydraulic jump is cons... more The effect of an abruptly expanding channel on the main characteristics of hydraulic jump is considered experimentally. The present study was made for supercritical flow of Froude number varying between 2 to 9 and approach to expanded channel width ratios 0.4, 0.5, 0.6 and 0.8. Physical explanations of the variation of these characteristics under varying flow conditions are discussed based on the observation drawn from experimental results. The analytical equation for the sequent depth ratio in an abruptly expanding channel as given by eminent hydraulic engineers are verified well with the experimental data for all expansion ratios, and the empirical relation was also verified with the present experimental data.
Portugaliae Electrochimica Acta, 2020
A comparative study of the corrosion behavior of pure magnesium and AZ91D anodes in reinforced ce... more A comparative study of the corrosion behavior of pure magnesium and AZ91D anodes in reinforced cement concrete was undertaken in the present work. The steel reinforcements were electrochemically kept in contact with these anodes in a chloride atmosphere, and the half-cell potential drop was observed. Bare steel reinforcements were tied to the anodes and were also kept in a high chloride atmosphere to test the mechanical properties. The yield stress and ultimate tensile stress were found to decrease by approximately 50 MPa, while the reduction in percentage elongation was approximately 25% for reinforcements tied to AZ91D and pure Mg, at the end of 80 days, compared to the fresh steel reinforcement. The rate of corrosion of pure Mg was reportedly slightly higher compared to AZ91D, due to the presence of inter-metallics, as inferred through micro-graphs.
International Journal of Mechanical Engineering
The transport of fluids through pipes is very common in core engineering practice. The main issue... more The transport of fluids through pipes is very common in core engineering practice. The main issue that came up when the pipe flow networks were its analysis part. The Hardy Cross approach is very accurate and reliable for solving these issues, but because it is iterative, the likelihood of errors increases as the number of circuit loops grows. Therefore, in this research, a piece of effort has been made to automate the Hardy Cross technique using Python programming (as it is userfriendly and has a large library backup) to remove the errors that come with using hand calculations. The built program has been applied to four different pipe flow network problems, and the outcomes are the same as those presented in the literature.
Emerging Materials Research
In this research, the benefits of nano-titanium dioxide (nano-TiO2) concrete over pure concrete i... more In this research, the benefits of nano-titanium dioxide (nano-TiO2) concrete over pure concrete in resisting the impacts of chloride diffusion were investigated. An increasing accelerative effect of chloride diffusion was experimentally discovered, which coincided with the movement in the exposed concrete surface caused by diffusion and the damage in concrete microstructure caused by chloride salt accumulation. The ‘time lag’ and ‘equivalent time’ between diffusion and migration tests were used to calculate the steady- and non-steady-state chloride diffusion coefficients. Concrete containing 2% nano-titanium dioxide by weight of cement demonstrated improved impermeability when compared with pure concrete, owing to improvements in microstructure and porosity. In comparison with pure concrete, the concrete containing nano-titanium dioxide had superior performance in resisting the effects of chloride diffusion. Because of its superfine particle size distribution and ‘filler’ effect, na...
Asian Journal of Civil Engineering
The current paper experimentally investigates the effects of partial replacement of cement by nan... more The current paper experimentally investigates the effects of partial replacement of cement by nano-TiO 2 (NT) in concrete in varying proportions by weight. NT was added by weight of cement with partial replacement of 0%, 0.5%, 1.5%, 2.0%, 2.5%, and 3.0% using Portland Pozzolana Cement in C20/25 grade of concrete. The physical and mechanical properties of concrete so produced were evaluated and durability aspects such as slump, sorptivity, half-cell potential, and drying shrinkage were also conducted. The fresh concrete produced showed a drastic reduction of the slump with increasing percentage replacement with 74% reduction at 3.0% replacement compared to the control mix. Further, the 7, 28, 56, and 90 days compressive, flexural, and split tensile strength showed a peak at 1.5% NT after which the values dropped in strength by 34.5%, 27%, and 19% concerning the control mix for 2.0%, 2.5%, and 3.0% replacement levels, respectively. From the microstructural studies, it could be concluded that nano-TiO 2 acts as a filler material and can be used as a partial replacement for cement effectively up to 3% of the weight of cement in concrete. Thus, incorporating nanoparticles could cause more strength and resistance to water permeability of the specimens.
The Asian Review of Civil Engineering
In this research article an attempt has been made to analyse the design wind pressure on the rect... more In this research article an attempt has been made to analyse the design wind pressure on the rectangular buildings using Python programming. For this purpose, design wind pressure is calculated and compared using IS 875 (Part 3) 1987 and the revised code IS 875 (Part 3) 2015. The concept have been applied to three different building heights i.e. 20, 40, and 60 m having same plan 1010 m2. It has been observed that the impact of wind pressure on the building rises with the building height along with the fact that the design wind pressures obtained from revised code show more pressures in comparison to the old one. Therefore, the design based on the revised code will be more close to the reality as it incorporates risk factor, directionality factor, area averaging factor, and combination factors. Also, the module developed for wind loads can be readily used by the researchers/designers for the better understanding of programming and the design loads.
ACI Materials Journal
The current paper investigates the effects of partial cement replacement with nano-titanium dioxi... more The current paper investigates the effects of partial cement replacement with nano-titanium dioxide (nano-TiO 2 [NT]) in varying weight proportions in concrete. In the C20/25 grade of concrete, NT was added by weight of cement with partial replacement of 0, 0.5, 1.5, 2.0, 2.5, and 3.0% using portland pozzolana cement. The physical and mechanical properties of the resulting concrete were assessed, as well as aspects of durability such as sorptivity and nondestructive tests (NDT) such as ultrasonic pulse velocity (UPV). Compared with the control mixture, the fresh concrete produced showed a drastic reduction in slump with increasing percentage of replacement, with a 54% reduction at a 3.0% replacement. Furthermore, for 1.5% NT, the compressive, flexural, and splitting tensile strengths peaked at 7, 28, 56, and 90 days, after which the values decreased. The addition of NT improved the homogeneity and integrity of the resulting concrete based on the UPV values. As the percentage of NT increased, chloride penetration decreased. From microstructural studies, it can be concluded that NT acts as a filler material and can be used as a partial replacement for cement in concrete up to 2% by weight.
The effect of an abruptly expanding channel on the main characteristics of hydraulic jump is cons... more The effect of an abruptly expanding channel on the main characteristics of hydraulic jump is considered experimentally. The present study was made for supercritical flow of Froude number varying between 2 to 9 and approach to expanded channel width ratios 0.4, 0.5, 0.6 and 0.8. Physical explanations of the variation of these characteristics under varying flow conditions are discussed based on the observation drawn from experimental results. The analytical equation for the sequent depth ratio in an abruptly expanding channel as given by eminent hydraulic engineers are verified well with the experimental data for all expansion ratios, and the empirical relation was also verified with the present experimental data.
Corrosion of reinforcements in reinforced cement concrete structures is an active area of researc... more Corrosion of reinforcements in reinforced cement concrete structures is an active area of research in civil engineering. One of the method of corrosion prevention being cathodic or sacreficial protection. The current work investigates the effect of using pure Mg and AZ91D as sacrificial anodes in ordinary and marine atmosphere on concrete slabs containing partial replacements of cement and fine aggregates by sugar cane bagasse ash (SCBA) and mill scale (MS) respectively by half cell potential (HCP) studies for 270 days. Twelve slabs were casted with centrally placed anodes, tied with the reinforcement cage and HCP readings were observed for 280 days at different locations of the slabs. Slabs were casted without and with 3.5 wt% NaCl. It is observed that at the end of 280 days the slab without any replacement and containing 3.5 wt% NaCl showed maximum values of HCP, whereas, the slabs containing MS or SCBA without any Cl content, showed least HCP values. This is because both MS and S...
Hydraulic jump is most frequently encountered features of RVF in open channels as the supercritic... more Hydraulic jump is most frequently encountered features of RVF in open channels as the supercritical flow changes to subcritical flow; during this phenomenon air is entrained because of the breaking of number of wavelets on the surface and get released in the form of air bubbles. Compared to prismatic, non-prismatic channels with appurtenances not only modify the hydraulic jump characteristics but also affect significantly the formation of symmetric flows downstream of the channel. Moreover, non-prismatic channels with baffle blocks & sill arrangements are useful to control the hydraulic jump in stilling basins when there is deficiency of tail water depth and the places where there is design constraints in order to reduce the basin length. It is also useful in the situations where it is impossible to depress the basin floor because of difficulties in excavation; a lateral expansion remains the only option for the required dissipation of energy through formation of hydraulic jump. For...
Present study deals with the bed load transport and shear stress with uniform and nonuniform sedi... more Present study deals with the bed load transport and shear stress with uniform and nonuniform sediments in an open channel under different experimental conditions. Effort has been made to analyse extensive experimental results in comparison with the existing theories given by the various eminent researchers for both the types of sediment materials. Empirical relations are proposed by dimensionless approach with the help of Buckingham-π theorem in terms of dimensionless shear stress and bed load transport parameter. Results are compared and vaidated with Meunier (2006) and Roorkee‟s approach [i.e. Gilbert (1914), Pazis & Graf, Paintal (1977), Misri et. al (1984), Ranga Raju & R. J. Garde (1986)] for both uniform and non uniform sediment material. © 2016 Elixir all rights reserved. Elixir Civil Engg. 91 (2016) 38310-38314 Civil Engineering Available online at www.elixirpublishers.com (Elixir International Journal) Sumit Gandhi et al./ Elixir Civil Engg. 91 (2016) 38310-38314 38311 only...
IOP Conference Series: Earth and Environmental Science, 2021
The use of agricultural wastes rich in pozzolanic materials such as Fe2O3, SiO2 and Al2O3 is an a... more The use of agricultural wastes rich in pozzolanic materials such as Fe2O3, SiO2 and Al2O3 is an active area of research in concrete technology. This improves the mechanical and durability properties along with sustainability. One such waste is the Sugar Cane Bagasse Ash (SCBA) generated by sugar mills and usually dumped in open space. The main purpose of the study is to investigate synergic effect of cathodic protection and using SCBA blended cement concrete on the corrosion resistance of embedded reinforcement and compare it with control concrete. The approach involved construction of eight slabs (1 m X 0.1 m X 0.1 m) and monitoring the half cell potential (HCP) for 270 days. In order to simulate the marine atmosphere, two slabs were constructed with 3.5% NaCl by weight of cement and two others were reference slabs. The pure Magnesium anodes 22 mm diameter and 250 mm long were used. The experimental results indicated that the corrosion of embedded reinforcement in slab containing S...
Civil Engineering Journal, 2018
Comparative study of the corrosion behavior of pure Magnesium and AZ91D anodes in reinforced ceme... more Comparative study of the corrosion behavior of pure Magnesium and AZ91D anodes in reinforced cement concrete was undertaken in the present work. The steel reinforcements were kept in contact with these anodes electrochemically in chloride atmosphere and the half-cell potential drop was observed. Bare steel reinforcements were tied to the anodes and were also kept in high chloride atmosphere to test the mechanical properties. The yield stress and ultimate tensile stress were found to decrease by approximately 50MPa while the reduction in percentage elongation is approximately 25% for reinforcements tied to AZ91D and pure Mg at the end of 80 days compared to fresh steel reinforcement. The rate of corrosion of pure Mg was reportedly slightly higher compared to AZ91D due to the presence of inter-metallics as inferred through micro-graphs.
IOP Conference Series: Materials Science and Engineering, 2018
The current work investigates the performance of pure Magnesium on corrosion prevention of steel ... more The current work investigates the performance of pure Magnesium on corrosion prevention of steel reinforcements by way of sacrificial anoding. Two set of six steel reinforcements were tested for half-cell potential, weight loss, anode efficiency and tensile strength for each of the sacrificial anodes in a high chloride atmosphere of 7.5% NaCl in tap water. Significant reduction in weight of anode was observed during the initial 12 days. The reduction in weight of steel reinforcements tied with anodes was found to be negligible, while that of reinforcements without anodes was significantly higher. Five distinct zones of corrosion were observed during the test. The tensile strength of steel cathodically protected by Mg alloy anodes was found less affected. It could be concluded that pure Mg anode provides an effective way of corrosion mitigation.
International journal of physical sciences
ABSTRACT
International Journal of Fluid Mechanics Research, 2014
Journal of The Institution of Engineers (India): Series A, 2016
Empirical relations for hydraulic jump characteristics, viz. sequent depth ratio (Y 2 /Y 1), effi... more Empirical relations for hydraulic jump characteristics, viz. sequent depth ratio (Y 2 /Y 1), efficiency of jump (E 2 /E 1) and relative length of jump (L j /Y 1) in trapezoidal channel with/without appurtenances are developed by introducing dimensionless Reynolds number, and neglecting the frictional effect for approach Froude number (varied between 2 and 10 under different conditions). Developed empirical models were also validated and compared with acquired experimental data as well as with literature data. Close fitness of the empirical models with appurtenances under varying dimensions, positions of baffle blocks provides accurate prediction of same for higher value of Froude number. Keywords Trapezoidal channel Á Hydraulic jump Á Energy dissipation Á Reynolds number Á Baffles q Density of water, Kg/m 3 l Dynamic viscosity of water, Ns/m 2 e Surface roughness, m h Side slope angle
Empirical relations for hydraulic jump characteristics, viz. sequent depth ratio (Y 2 /Y 1), effi... more Empirical relations for hydraulic jump characteristics, viz. sequent depth ratio (Y 2 /Y 1), efficiency of jump (E 2 /E 1) and relative length of jump (L j /Y 1) in non-prismatic channel (i.e., suddenly expanding) with/without appurtenances are developed by introducing dimensionless Reynolds number, and neglecting the frictional effect for approach Froude numbers between 2 to 9 under different channel conditions. Developed empirical models were also tested, validated and compared with acquired experimental data as well as with literature data. Close fitness of the empirical models with appurtenances under varying dimensions, positions of baffle blocks and end sill provides accurate prediction of same for higher value of Froude number.