Amir Tarighat | Shahid Rajaii Teacher Training University (original) (raw)
Books by Amir Tarighat
Papers by Amir Tarighat
Original Research Paper Received 23 March 2016 Accepted 07 May 2016 Available Online 11 June 2016... more Original Research Paper Received 23 March 2016 Accepted 07 May 2016 Available Online 11 June 2016 The cement paste properties as the matrix in concrete are of great importance in specifying its properties. Recent advances in concrete industry have highlighted the need for accurate knowledge about its nano-structure and components. To estimate the important mechanical properties such as Young's modulus, bulk modulus and Poisson’s ratio of the hardened cement paste at the nanoscale, a comprehensive set of crystalline structures that represent the main hardened cement paste constituents (CSH, CH, Ettringite, Hydrogarnet and monosulphoaluminate) is developed for Molecular Dynamics (MD) simulations. Five different force fields (COMPASS, COMPASS II, INTERFACE, Universal and Deriding) were used and compared with each other to be able to measure the mechanical properties of these compounds. Also, the properties of two types of C-S-H with high and low density were determined by using Mor...
Bridge Maintenance, Safety and Management, 2010
Journal of Elastomers and Plastics, Oct 18, 2017
The object of this work is to study and predict the tensile properties (tensile strength, elastic... more The object of this work is to study and predict the tensile properties (tensile strength, elastic modulus, and elongation at break) of ternary nanocomposites based on epoxy/ glass fiber/nanosilica using the fuzzy logic (FL). Two factors in three levels including glass fiber at 0, 5, and 10 wt% and nanosilica at 0, 0.5, and 1 wt% were chosen for adding to an epoxy matrix. From FL surfaces, it was found that the glass fiber content had a main role in the tensile properties of nanocomposites. The high levels of glass fiber content led to a significant increase in the elastic modulus and generally, the presence of glass fiber decreased the tensile strength and elongation at break. Also, addition of the nanosilica content resulted in an increased elastic modulus but decreased the elongation at break of nanocomposites. Finally, an FL model was obtained for each tensile property.
International Journal of Civil Engineering, Feb 19, 2018
Now a days, the increased use of scrap/waste as construction material has proved to be very harmf... more Now a days, the increased use of scrap/waste as construction material has proved to be very harmful for the environment particularly in tropical countries like Pakistan. Researchers are trying at their best to reduce the adverse impact of waste material on the required environment but yet until more work is required in this regard. In this research paper authors have tried to reuse Silica Fume as construction material as it is very easily available in market as waste material from raw material /by-product industrial waste materials used in mills. The Authors obtained silica fume after proper screening the concerned industrial waste. These industries are available in grater quantity in the province of sindh. The required waste material is available in huge quantity. Silica is very important construction material and by using this as waste we can protect our environment by reusing or proper use of waste material. Here, researchers took different percentage of silica fume and mixed with concrete in varying ratio as replacement of Ordinary Portland Cement as active material in laboratory. Results were came, very interesting and found Tensile Strength, Compressive Strength and Flexural Strengths near to Ordinary Portland Cement also other properties of concrete like pH value, Slump, Curing and Temperature of Concrete shows satisfactory results at various percentage of Replacement with Ordinary Portland Cement. The research work has yielded the satisfactory results and the silica fume can be used effectively as an active construction material. Different percentage shows different results but at 5% and 10% mixing of silica fume indicated high strength as compare to ordinary cement mix and the controlled temperature 28 0 c. Further, Engineering is a vast field and it needs more research with passage of time.
Construction and Building Materials
international journal of engineering & technology sciences, 2014
Bridge management systems call for realized and efficient performance prediction methodologies to... more Bridge management systems call for realized and efficient performance prediction methodologies to optimize the resources used in bridge inspection, maintenance and repair. A spatial time-dependent reliability model for performance prediction of reinforced concrete bridges exposed to corrosion is presented. This model can be considered as the core of a methodology for performance updating of deteriorating concrete bridges. The proposed methodology is based on the Bayesian analysis and utilizes data reported by health monitoring systems. It helps to evaluate the reliability of a reinforced concrete bridge exposed to corrosion. It was found that the proposed probabilistic reliability model incorporating health monitoring system improves the future corrosion damage predictions with more accuracy and less variability.
The paper proposes an image mosaicking method for tunnel lining inspection. The conventional meth... more The paper proposes an image mosaicking method for tunnel lining inspection. The conventional methods only used the cost value of the pixel being processed based on similarity metric to estimate an image-matching location. To improve the image-mosaicking efficiency, the curvature metric has adapted to improve matching point accuracy. Experimental results for an actual tunnel demonstrate that the curvature measurement can select the precise matching points accurately for assisting defect inspection without depending on the speed of inspection vehicle.
Practice Periodical on Structural Design and Construction
In this paper, the effects of different aluminum to silicon ratios in silicate chains of calcium ... more In this paper, the effects of different aluminum to silicon ratios in silicate chains of calcium silicate hydrates (C-S-H) are evaluated on the diffusion coefficient of chloride ions by molecular dynamics method. Tobermorite is a crystalline phase that is used for studying C-S-H properties in nano scale, because of its analogous chemical composition to C-S-H. Aluminum incorporation in C-S-H and the formation of calcium aluminosilicate hydrates (C-A-S-H) is due to both of hydration of tricalcium aluminate (C3A) in portland cement and aluminum oxides in pozzolans. There exist different Al/Si ratios in the tetrahedral chains of C-A-S-H depending on available aluminum oxides in cementitious raw materials. In order to compare the simulation results with previously-published experimental researches on cement pastes, a novel method is introduced here to calculate Al/Si ratio in tetrahedral chains of C-A-S-H using pozzolan replacement ratio in cementitious paste. MK (metakaolin) and FC3R (F...
Fuzzy Inference System - Theory and Applications, 2012
امروزه پوزولانها به عنوان جایگزینهای مناسبی برای سیمان از لحاظ افزایش مقاومت و دوام بتن در شرای... more امروزه پوزولانها به عنوان جایگزینهای مناسبی برای سیمان از لحاظ افزایش مقاومت و دوام بتن در شرایط محیطی نامناسب، صرفهجویی در مصرف انرژی و کاهش آلودگی محیط زیست محسوب میشوند. در این مقاله تأثیر ترکیب رسهای کلسینه به عنوان پوزولان و میکروسیلیس و تأثیر هرکدام نیز به تنهایی مورد بررسی قرار گرفته است. برای این منظور 15 طرح مخلوط با نسبت آب به موادسیمانی 38/0 ساخته شده است. در شش طرح فقط متاکائولن، زئولیت و یا میکروسیلیس وجود دارد و در هشت طرح دیگر متاکائولن و میکروسیلیس و یا زئولیت و میکروسیلیس با هم ترکیب شدهاند. متاکائولن یا زئولیت با نسبت 10 یا 20 درصد و میکروسیلیس با نسبت 7 یا 10 درصد جایگزین سیمان مصرفی شدهاند. یافتههای اصلی این تحقیق نشان میدهد که استفاده از این نوع پوزولانها میتواند سبب بهبود مقاومت فشاری و مقاومت الکتریکی بتن شود، به گونهای که بهترین عملکرد تا سن 28 روز برای مقاومت فشاری مربوط به جایگزینی ترکیب 10درصد زئولیت با 7 درصد میکروسیلیس و برای مقاومت الکتریکی مربوط به جایگزینی ترکیب 10 درصد زئولیت با 10 درصد میکروسیلیس است.امروزه پوزولانها به عنوان جایگزین...
Geotechnical and Geological Engineering
Civil engineering infrastructures journal, 2014
Corrosion of steel reinforcement is one of the most prevalent causes of reinforced concrete (RC) ... more Corrosion of steel reinforcement is one of the most prevalent causes of reinforced concrete (RC) structures deterioration in chloride-contaminated environments. As a result, evaluating the impact of any possible corrosion-induced damages to reinforced concrete bridges strongly affects management decisions: such as inspection, maintenance and repair actions. The corrosion propagation phase is a significant factor in the service life of reinforced concrete structures and thus, it is requires appropriate attention. Various models have been developed to simulate and/or predict the propagation phase. This paper proposes that a method in which a reliability framework is developed to assess the durability of reinforced concrete structures under corrosion inmarine environments functions better. The main concern of this study is chloride-induced corrosions.In due regard, serviceability and ultimate limit states of the structure are also taken into account. Subsequently, the proposed method i...
pphmj.com
In this study, acquisition of rule-type knowledge from bridge database is enhanced by introducing... more In this study, acquisition of rule-type knowledge from bridge database is enhanced by introducing an improvement to traditional data mining, ie, applying rough set theory into traditional decision table reduction method. The new rough set theory approach helps in ...
Article history: Received: 07 May 2015 Accepted: 17 October 2018 This study addressed the efficie... more Article history: Received: 07 May 2015 Accepted: 17 October 2018 This study addressed the efficiency of ultrasonic pulse velocity (UPV) as a nondestructive test in concrete in estimating the mechanical (compressive and tensile strength) and durability (water absorption) properties of fiberreinforced self-compacting concrete. To do so, 11 mixture designs containing 3 fiber types (steel: 0.1, 0.2, 0.3 and 0.4 percent by volume, Poly-phenylene Sulfide (PPS): 0.1, 0.2, 0.3 and 0.4% by volume and poly-propylene: 0.1 and 0.2 percent by volume) and a design without fibers as reference concrete have been tested and compared. To measure ultrasonic pulse velocity, cubic specimens were tested. The obtained results were used to develop correlation relationships between UPV of the specimens and the compressive and tensile strength as well as water absorption. For the self-compacting concrete in this study, the range of pulse velocity was obtained. The proposed relations accurately estimate the m...
Journal of Rehabilitation in Civil Engineering, 2019
Approximately, 50 to 70 percent of hydration products in hydrated cement paste are polymorphisms ... more Approximately, 50 to 70 percent of hydration products in hydrated cement paste are polymorphisms of C-S-H gel. It is highly influential in the final properties of hardened cement paste. Distinguishing C-S-H nano-structure significantly leads to determine its macro scale ensemble properties. This paper is dealt with nano-scale modeling. To achieve this, the most important C-S-H compounds, with a vast range ratios of Ca/Si from 0.5 to 3 were chosen and used in different simulations. These materials included tobermorite 9A, tobermorite 11A, tobermorite 14A, clinotobermorite, jennite, afwillite, okenite, jaffeite, foshagite, and wollastonite. Furthermore, the molecular dynamics method was used to estimate important mechanical properties such as bulk modulus, shear modulus, Young's modulus and poisson ratio. Five different force fields (COMPASS, COMPASS II, ClayFF, INTERFACE and Universal) were used and compared with each other to be able to measure the mechanical properties of these...
Original Research Paper Received 23 March 2016 Accepted 07 May 2016 Available Online 11 June 2016... more Original Research Paper Received 23 March 2016 Accepted 07 May 2016 Available Online 11 June 2016 The cement paste properties as the matrix in concrete are of great importance in specifying its properties. Recent advances in concrete industry have highlighted the need for accurate knowledge about its nano-structure and components. To estimate the important mechanical properties such as Young's modulus, bulk modulus and Poisson’s ratio of the hardened cement paste at the nanoscale, a comprehensive set of crystalline structures that represent the main hardened cement paste constituents (CSH, CH, Ettringite, Hydrogarnet and monosulphoaluminate) is developed for Molecular Dynamics (MD) simulations. Five different force fields (COMPASS, COMPASS II, INTERFACE, Universal and Deriding) were used and compared with each other to be able to measure the mechanical properties of these compounds. Also, the properties of two types of C-S-H with high and low density were determined by using Mor...
Bridge Maintenance, Safety and Management, 2010
Journal of Elastomers and Plastics, Oct 18, 2017
The object of this work is to study and predict the tensile properties (tensile strength, elastic... more The object of this work is to study and predict the tensile properties (tensile strength, elastic modulus, and elongation at break) of ternary nanocomposites based on epoxy/ glass fiber/nanosilica using the fuzzy logic (FL). Two factors in three levels including glass fiber at 0, 5, and 10 wt% and nanosilica at 0, 0.5, and 1 wt% were chosen for adding to an epoxy matrix. From FL surfaces, it was found that the glass fiber content had a main role in the tensile properties of nanocomposites. The high levels of glass fiber content led to a significant increase in the elastic modulus and generally, the presence of glass fiber decreased the tensile strength and elongation at break. Also, addition of the nanosilica content resulted in an increased elastic modulus but decreased the elongation at break of nanocomposites. Finally, an FL model was obtained for each tensile property.
International Journal of Civil Engineering, Feb 19, 2018
Now a days, the increased use of scrap/waste as construction material has proved to be very harmf... more Now a days, the increased use of scrap/waste as construction material has proved to be very harmful for the environment particularly in tropical countries like Pakistan. Researchers are trying at their best to reduce the adverse impact of waste material on the required environment but yet until more work is required in this regard. In this research paper authors have tried to reuse Silica Fume as construction material as it is very easily available in market as waste material from raw material /by-product industrial waste materials used in mills. The Authors obtained silica fume after proper screening the concerned industrial waste. These industries are available in grater quantity in the province of sindh. The required waste material is available in huge quantity. Silica is very important construction material and by using this as waste we can protect our environment by reusing or proper use of waste material. Here, researchers took different percentage of silica fume and mixed with concrete in varying ratio as replacement of Ordinary Portland Cement as active material in laboratory. Results were came, very interesting and found Tensile Strength, Compressive Strength and Flexural Strengths near to Ordinary Portland Cement also other properties of concrete like pH value, Slump, Curing and Temperature of Concrete shows satisfactory results at various percentage of Replacement with Ordinary Portland Cement. The research work has yielded the satisfactory results and the silica fume can be used effectively as an active construction material. Different percentage shows different results but at 5% and 10% mixing of silica fume indicated high strength as compare to ordinary cement mix and the controlled temperature 28 0 c. Further, Engineering is a vast field and it needs more research with passage of time.
Construction and Building Materials
international journal of engineering & technology sciences, 2014
Bridge management systems call for realized and efficient performance prediction methodologies to... more Bridge management systems call for realized and efficient performance prediction methodologies to optimize the resources used in bridge inspection, maintenance and repair. A spatial time-dependent reliability model for performance prediction of reinforced concrete bridges exposed to corrosion is presented. This model can be considered as the core of a methodology for performance updating of deteriorating concrete bridges. The proposed methodology is based on the Bayesian analysis and utilizes data reported by health monitoring systems. It helps to evaluate the reliability of a reinforced concrete bridge exposed to corrosion. It was found that the proposed probabilistic reliability model incorporating health monitoring system improves the future corrosion damage predictions with more accuracy and less variability.
The paper proposes an image mosaicking method for tunnel lining inspection. The conventional meth... more The paper proposes an image mosaicking method for tunnel lining inspection. The conventional methods only used the cost value of the pixel being processed based on similarity metric to estimate an image-matching location. To improve the image-mosaicking efficiency, the curvature metric has adapted to improve matching point accuracy. Experimental results for an actual tunnel demonstrate that the curvature measurement can select the precise matching points accurately for assisting defect inspection without depending on the speed of inspection vehicle.
Practice Periodical on Structural Design and Construction
In this paper, the effects of different aluminum to silicon ratios in silicate chains of calcium ... more In this paper, the effects of different aluminum to silicon ratios in silicate chains of calcium silicate hydrates (C-S-H) are evaluated on the diffusion coefficient of chloride ions by molecular dynamics method. Tobermorite is a crystalline phase that is used for studying C-S-H properties in nano scale, because of its analogous chemical composition to C-S-H. Aluminum incorporation in C-S-H and the formation of calcium aluminosilicate hydrates (C-A-S-H) is due to both of hydration of tricalcium aluminate (C3A) in portland cement and aluminum oxides in pozzolans. There exist different Al/Si ratios in the tetrahedral chains of C-A-S-H depending on available aluminum oxides in cementitious raw materials. In order to compare the simulation results with previously-published experimental researches on cement pastes, a novel method is introduced here to calculate Al/Si ratio in tetrahedral chains of C-A-S-H using pozzolan replacement ratio in cementitious paste. MK (metakaolin) and FC3R (F...
Fuzzy Inference System - Theory and Applications, 2012
امروزه پوزولانها به عنوان جایگزینهای مناسبی برای سیمان از لحاظ افزایش مقاومت و دوام بتن در شرای... more امروزه پوزولانها به عنوان جایگزینهای مناسبی برای سیمان از لحاظ افزایش مقاومت و دوام بتن در شرایط محیطی نامناسب، صرفهجویی در مصرف انرژی و کاهش آلودگی محیط زیست محسوب میشوند. در این مقاله تأثیر ترکیب رسهای کلسینه به عنوان پوزولان و میکروسیلیس و تأثیر هرکدام نیز به تنهایی مورد بررسی قرار گرفته است. برای این منظور 15 طرح مخلوط با نسبت آب به موادسیمانی 38/0 ساخته شده است. در شش طرح فقط متاکائولن، زئولیت و یا میکروسیلیس وجود دارد و در هشت طرح دیگر متاکائولن و میکروسیلیس و یا زئولیت و میکروسیلیس با هم ترکیب شدهاند. متاکائولن یا زئولیت با نسبت 10 یا 20 درصد و میکروسیلیس با نسبت 7 یا 10 درصد جایگزین سیمان مصرفی شدهاند. یافتههای اصلی این تحقیق نشان میدهد که استفاده از این نوع پوزولانها میتواند سبب بهبود مقاومت فشاری و مقاومت الکتریکی بتن شود، به گونهای که بهترین عملکرد تا سن 28 روز برای مقاومت فشاری مربوط به جایگزینی ترکیب 10درصد زئولیت با 7 درصد میکروسیلیس و برای مقاومت الکتریکی مربوط به جایگزینی ترکیب 10 درصد زئولیت با 10 درصد میکروسیلیس است.امروزه پوزولانها به عنوان جایگزین...
Geotechnical and Geological Engineering
Civil engineering infrastructures journal, 2014
Corrosion of steel reinforcement is one of the most prevalent causes of reinforced concrete (RC) ... more Corrosion of steel reinforcement is one of the most prevalent causes of reinforced concrete (RC) structures deterioration in chloride-contaminated environments. As a result, evaluating the impact of any possible corrosion-induced damages to reinforced concrete bridges strongly affects management decisions: such as inspection, maintenance and repair actions. The corrosion propagation phase is a significant factor in the service life of reinforced concrete structures and thus, it is requires appropriate attention. Various models have been developed to simulate and/or predict the propagation phase. This paper proposes that a method in which a reliability framework is developed to assess the durability of reinforced concrete structures under corrosion inmarine environments functions better. The main concern of this study is chloride-induced corrosions.In due regard, serviceability and ultimate limit states of the structure are also taken into account. Subsequently, the proposed method i...
pphmj.com
In this study, acquisition of rule-type knowledge from bridge database is enhanced by introducing... more In this study, acquisition of rule-type knowledge from bridge database is enhanced by introducing an improvement to traditional data mining, ie, applying rough set theory into traditional decision table reduction method. The new rough set theory approach helps in ...
Article history: Received: 07 May 2015 Accepted: 17 October 2018 This study addressed the efficie... more Article history: Received: 07 May 2015 Accepted: 17 October 2018 This study addressed the efficiency of ultrasonic pulse velocity (UPV) as a nondestructive test in concrete in estimating the mechanical (compressive and tensile strength) and durability (water absorption) properties of fiberreinforced self-compacting concrete. To do so, 11 mixture designs containing 3 fiber types (steel: 0.1, 0.2, 0.3 and 0.4 percent by volume, Poly-phenylene Sulfide (PPS): 0.1, 0.2, 0.3 and 0.4% by volume and poly-propylene: 0.1 and 0.2 percent by volume) and a design without fibers as reference concrete have been tested and compared. To measure ultrasonic pulse velocity, cubic specimens were tested. The obtained results were used to develop correlation relationships between UPV of the specimens and the compressive and tensile strength as well as water absorption. For the self-compacting concrete in this study, the range of pulse velocity was obtained. The proposed relations accurately estimate the m...
Journal of Rehabilitation in Civil Engineering, 2019
Approximately, 50 to 70 percent of hydration products in hydrated cement paste are polymorphisms ... more Approximately, 50 to 70 percent of hydration products in hydrated cement paste are polymorphisms of C-S-H gel. It is highly influential in the final properties of hardened cement paste. Distinguishing C-S-H nano-structure significantly leads to determine its macro scale ensemble properties. This paper is dealt with nano-scale modeling. To achieve this, the most important C-S-H compounds, with a vast range ratios of Ca/Si from 0.5 to 3 were chosen and used in different simulations. These materials included tobermorite 9A, tobermorite 11A, tobermorite 14A, clinotobermorite, jennite, afwillite, okenite, jaffeite, foshagite, and wollastonite. Furthermore, the molecular dynamics method was used to estimate important mechanical properties such as bulk modulus, shear modulus, Young's modulus and poisson ratio. Five different force fields (COMPASS, COMPASS II, ClayFF, INTERFACE and Universal) were used and compared with each other to be able to measure the mechanical properties of these...
Civil engineering infrastructures journal, 2019
The production of ordinary Portland cement (OPC) as the most expensive constituent of concrete is... more The production of ordinary Portland cement (OPC) as the most expensive constituent of concrete is associated with destructive environmental effects and significant energy consumption. Thus, the use of supplementary cementitious materials such as Natural or synthetic pozzolans is a fundamental solution that affects the kinetics of hydration of cementitious materials. In this article, to evaluate the effect of ball clay in the presence or absence of silica fume on the performance of cementitious materials, compressive strength and ultrasonic tests were performed at replacement weight percentages of 0, 10 and 20% for ball clay and 0 and 7% for silica fume. Also, thermodynamic modeling during hydration was carried out based on the Gibbs free energy minimization. The results showed that mere presence of ball clay does not have a positive effect, but it can improve the structure and strength of cement in the presence of silica fume, since it resulted in complete consumption of portlandite...