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Showing 149 results for Asadi


Volume 18, Issue 120 (February 2021)
Abstract

Celiac is an immune-mediated disease where genetically predisposed individuals exhibit intolerance to peptides released from wheat gluten. Patients with celiac disease are unable to consume the foodstuffs containing gluten. As a result, the production of gluten-free products has received extensive attention for researchers. In this study, production of traditional gluten-free bread as treatment control (50% corn flour + 50% rice flour), treatment 1 (35% rice flour + 35% corn flour + 10% wheat germ flour + 5% mung bean flour + 15% lentil germ flour), treatment 2 (20% rice flour + 20% corn flour + 25% wheat germ flour + 15% mung bean germ flour + 20% lentil germ flour), treatment 3 (5% rice flour + 5% corn flour + 35% wheat germ flour + 20% mung bean flour + 35% lentil flour) were studied. Statistical analysis of data obtained from moisture, fat, protein, total ash, salt, calcium, pH, sensory characteristics showed that replacing rice flour and corn flour with wheat germ flour, lentils, mung bean The desired effect had significant effect on all parameters tested (P < 0.05). Comparison of the treatments with the treatment control showed that treatment 3 had the highest amount of wheat germ, lentil and mung bean flour had the highest amount of fat, protein, calcium, pH, salt and the lowest amount of moisture and had the highest score in sensory analysis.

Volume 18, Issue 121 (March 2022)
Abstract

Pomegranate is one of the important and an oldest fruit that is grown in vast regions. In recent years pomegranate juice is became a popular beverage. This study was carried out to investigate the mineral elements and some biochemical properties of juice in eight local Iranian pomegranate cultivars. The results showed a significant difference in the studied traits in all cultivars. The potassium content in pomegranate juice was higher than other elements, followed by calcium, sodium, phosphorus, magnesium, iron, manganese, zinc and copper. Potassium, calcium and iron was found the highest in chr('39')Golabichr('39'), meanwhile the highest amount of  magnesium and sodium measured in chr('39')Sorahichr('39') cultivars. chr('39')Aliakbarichr('39') had the highest amount of manganese and zinc and chr('39')Lopsorkhichr('39') and chr('39')Mirzaeichr('39') had the highest value of phosphorus and copper, respectively. The lowest amount of potassium and iron was observed in chr('39')Lopsorkhichr('39') and chr('39')Aliakbarichr('39') cultivars, respectively. For other elements, chr('39')Garchr('39') had the lowest concentration. In terms of biochemical properties such as total soluble solids (TSS), maturity index (MI) and acidity (pH) of juice, chr('39')Golabi, Lopsorkhi and Sorahichr('39') cultivars had the highest value. chr('39')Sorahichr('39') and chr('39')Aliakbarichr('39') cultivars with the highest amount of titrable acid were sour and suitable for industries pomegranate production, which require sour taste. Other cultivars were introduced due to the proper amounts of mineral elements and sweet and sour taste for fresh consumption and pomegranate juice production industry. The two-dimensional graph, based on the principal components analysis, confirmed the results of grouping the cultivars based on the comparison of the mean. 

Volume 19, Issue 1 (1-2017)
Abstract

 Risk assessment of soil erosion, one of the most important land degradation problems worldwide, is very essential for land and water resources management, and development of soil conservation methods. In the present study, the temporal changes of soil erosion risk were assessed from 1987 to 2010, based on the Revised Universal Soil Loss Equation (RUSLE) using Remote Sensing (RS) and Geographic Information Systems (GIS) for the Navrood Watershed, Iran, with an area of 270 km2. Two Landsat satellite imageries obtained in 1987 and 2010 were used to assess the changes in vegetation cover during this period, and to obtain the Cover factor (C) of RUSLE. Rainfall and soil texture data and a digital elevation model were used to calculate the rest of RUSLE factors, which were taken as constant for the study period. The results showed that the average annual soil loss over the watershed ranged from 0 to 1,056 t ha-1 y-1(Cumulative percentage> 99.9%). The area mapped as very high erosion risk (> 100 t ha-1 y-1) increased from 10% in 1987 to 12% in 2010, and the area of the next risk class (51-100 t ha-1 y-1) increased from 8 to 9%. These changes cover an area of about 800 ha in the watershed, in which erosion risk has been doubled or tripled in the last 23 years. Forest clearing and rangeland overgrazing were identified as the most important reasons for the increase in erosion risk.

Volume 19, Issue 1 (5-2019)
Abstract

Today, most seismic design codes reduce the lateral elastic force by the behavior factor to design structures, so that by designing a structure based on elastic analysis, the effects of non-elastic behavior of the structure are applied. To obtain a behavior factor of structures, a nonlinear analysis is necessary. Research has shown that the nonlinear behavior of RC members depends on factors such as the effect of varying axial load, the effect of shear failure of the members and the effect of the buckling of the longitudinal bars. It is now generally accepted that axial load plays a dominant role in evaluating the seismic behavior of reinforced concrete columns. However columns, especially the exterior ones, can be subjected to varying axial loads depending on the lateral loads. Also the effects of shear on beams and columns are usually neglected in nonlinear analysis, which is carried out based on the flexural behavior of each element. In this research, the behavior factor of 2, 4, and 8 story reinforced concrete frames with intermediate and special ductility based on the proposed nonlinear analysis is considered. Initially, for verification, the proposed nonlinear analysis model was compared with existing experimental models. The verification results show that the proposed model has a very high accuracy. Designing and detailing of the 2, 4 and 8 story reinforced concrete structures are on the basis of the regulation of the Standard 2800 and the National building regulation chapter 9. In order to obtain the behavior of the 2, 4, and 8 story reinforced concrete frames, the effect of varying axial load, shear failure of the members and the buckling of the longitudinal bars are considered in nonlinear analysis. The behavior factor is mostly effected by ductility factor and over strength factor. The ductility factor has dependence with ductility of the reinforced concrete frames. To obtain ductility of reinforced concrete frames, ultimate deformation is needed. To calculate the frames' behavior factor, various criteria are used to calculate the ultimate deformation of frames. One of the criteria is the deformation correspond to the 0.75 percent of ultimate rotation in critical structure member. The other criteria is the deformation correspond to ultimate rotation of critical structure member. The results of the study and comparison of the obtained behavior factor with the proposed behavior factor of the reinforced concrete structures of Standard 2800 with intermediate and special ductility have shown that the calculated behavior factor for 2, 4 and 8 story reinforced concrete frames is bigger than the behavior factor in Standard 2800. Also the results indicate that the calculated behavior factor with the ultimate deformation correspond to the 75 percent of ultimate rotation in critical structure member is close to the proposed value of Standard 2800. In intermediate reinforced concrete frames, the amount of ductility factor and over strength factor decreased when the height of the reinforced concrete frames raised, which is not seen in concrete frames with special ductility.


Volume 19, Issue 3 (Autumn 2019 2019)
Abstract

This paper aims to investigate the effect of social capital on banking stability in Iran. For this purpose, a sample of 18 public and private Iranian banks is selected over the period 2007-2017, and the System Generalized Method of Moments (SYS-GMM) is used to estimate the research model. The social capital index is proxied by the ratio of the bounced checks to the total traded checks. The results indicate a significant positive impact of social capital on bank stability. Moreover, the ratio of capital to asset and GDP per capita are positively associated with bank stability, but the non-performing loans have negative effects on bank stability.

Volume 19, Issue 4 (3-2016)
Abstract

To have successful career, one must acquire the competencies relevant to his/her business field. In order to share the knowledge in a successful and effective manner, individuals need to have knowledge sharing competencies. These competencies could affect and enhance individual performance. The purpose of this study is to investigate the impact of knowledge sharing intention on knowledge sharing competencies and also the impact of those competencies and knowledge sharing intention on managers’ performance in project-based organizations. Data is collected from 50 participants including top, middle and executive managers and also senior engineers. Statistical estimation methods and path analysis were utilized to test the hypotheses. The findings indicates that knowledge sharing intention not only has a positive and significant, direct impact on knowledge sharing competencies but also has a positive and significant, indirect impact on managers’ individual performance via knowledge sharing competencies. This study suggests that due to knowledge sharing intention, one can enhance his/her individual performance by developing the methodological competencies.

Volume 19, Issue 4 (7-2017)
Abstract

Rural cooperatives, as a small member-owned organizations, are the potential to facilitate socio-economic development in rural areas. Despite this fact, in Iran and many other developing countries, they have not had remarkable successes in this regard. Because strategy formulation and management is a plan to obtain far-reaching development effects of any organization. This study aimed to present a hybrid method to formulate and choose strategies for rural cooperatives development. It combined SWOT analysis, TOWS matrix, and the Analytic Network Process (ANP). We applied brainstorming technique to analyze the external and internal environment of rural cooperatives using the contributions of an experts’ team comprising 10 individual CEOs of rural cooperatives and senior employees of the Central Organization of Rural Cooperatives. When this team identified key SWOT factors, TOWS matrix was constructed to create good strategic alternatives. Finally, ANP was applied to prioritize the strategies. According to results, 19 key strategic factors such as lack of management knowledge (W4), and ability to improve value and supply chains (S4) were identified. In addition, this team identified 11 strategic alternatives which among them Implement public policy and provide technical and financial services (SO2), Facilitate procurement of inputs and develop supply and value chains (SO1) and Involve rural cooperatives in policy planning (ST1), had greater priority in Iran. The experts’ team believed that the presented combined approach helps decision makers and managers to make and choose the best alternative strategies and factors that affect rural cooperatives development.

Volume 19, Issue 77 (12-2022)
Abstract

In this research, different aspects of humor and contradictions and their types, in all the works of one of the most famous contradictors of Persian literature; That is, according to Atameh Shirazi, it was thoroughly studied by descriptive-analytical method and library resources, and for this purpose, from the theories of critics; Like Bakhtin, Joseph Shabili, Heather Dobrev, Arthur Pollard, were used. The findings show that legitimate contradictions are not merely comparative; Rather, they have various functions; Criticism of the poetic themes and ancient literary style of their time, by de-familiarization and violation of their purpose and protesting the economic and social situation of the people with this exaggerated trick that the theme of all past forms, from epic to lyric about food and food The generalities of his divan are a mixture of all kinds of humor and contradictions; Like Manipusi satire, allegory, satirical comedy, guaranteed contradiction, ridiculous epic, with irony and carnival laughter.
 

Volume 19, Issue 124 (June 2022)
Abstract

Due to the importance of bread in the diet of the worldchr('39')s people, it is vital to pay attention to increasing the nutritional properties of this product. In order to reduce the content of phytic acid and increase the shelf life, in this study, an attempt was made to investigate the effect of microencapsulation of amylase and phytase enzymes in bread. Chemical, physical, microbial, and sensory properties of whole-grain toast containing microencapsulated enzymes and free enzymes toasts were compared with the control sample (whole-grain toast and no enzyme). The results showed that samples containing free and encapsulated enzymes had less Phytic acid than the control sample (p≤0.05). The specific volume and porosity of the samples containing free and microencapsulated enzymes were higher, and their viscosity was lower than the control sample (p≤0.05). Samples containing enzymes had the lowest brightness, redness, and yellowness parameters than the control (p≤0.05). Control samples had lower numbers of mesophilic bacteria, mold, and yeast, and the samples containing the microencapsulated enzyme showed the highest sensory score by the fifth day of the test (p≤0.05). The results showed that encapsulated enzyme had a higher amount of phytic acid than the sample containing free enzyme. However, in other results, there was no difference between the microencapsulated and free samples, and the use of microencapsulated enzymes during storage led to Increasing the score of sensory properties, and it can be used to increase the quality of toast containing bran.

Volume 19, Issue 125 (July 2022)
Abstract


Nowadays, by converting the cheap and commercial low-valued fish into value-added products such as fish sausages, as well as the application of novel ohmic heating method to cook more uniform, faster compared to other thermal severe methods and with minimal processing can play an important role in producing a safe and nutritious product. Therefore, the purpose of this study is to investigate some microbial and chemical characteristics of (Saurida tumbil) greater lizardfish sausage heated by emerging ohmic heating method and formulation optimization was performed by response surface methodology -central composite design (RSM-CCD) by considering KCl (0.7- 2.3 %), Soy Oil ( 4-14 %) and Isolated Soy Protein (0.2-1.8%). Optimization of 20 fish sausage formulation produced by ohmic heating was done by response surface methodology using Design Expert software version 11 and the relationship between the independent variables and the five responses was investigated. KCl has been shown an inhibitory effect on samples total plate count level. The interaction effect of soybean oil and soy protein isolate had a significant effect on pH changes. Increasing soybean oil percentage caused a little increase and subsequently reduction of pH and increasing soy protein isolate led to a significant decrease in pH. Furthermore, higher amount of KCl and soy protein isolate reduced the amount of cooking loss. In addition increase of soy bean oil percentage caused reduction and increase of soy protein isolate lead to increase of water holding capacity. Based on the results of formulation optimization in fish sausages with formulations containing 2% potassium chloride, 6% soybean oil and 1.5% soy protein isolate can increase water holding capacity, the lowest microbial load and the lowest peroxide value, cooking loss and optimized pH.
 

Volume 19, Issue 127 (September 2022)
Abstract

There is an increasing demand for nondairy probiotic food due to the constraints associated with dairy probiotics. In this study, symbiotic drink was prepared from a mixture of mung bean, and rye sprouts inoculated with 1.38 * 108 CFU.ml-1 of Lactobacillus plantarum, and a Lactobacillus casei. In this regard, the effect of added prebiotics (inulin and oligofructose), and starter culture investigated on the probiotic viability during cold storage Furthermore, titrable acidity, pH, phenolic content, antioxidant activity and sensory attributes were assessed during 28 days. Resultant product showed good viability for L. casei (107 CFU.ml-1), and L. plantarum (106 CFU.ml-1) after 4 weeks under refrigerated conditions without any comprise in the quality. Prebiotics added to beverage resulted in the significant decrease in phenolic content (p < 0.05), probably because of the interaction between dietary fibers and phenolic compounds. Oligofructose and inulin improved the sensory scores. Treatments containing both probiotics and prebiotics showed the highest sensory scores during storage (p <0.05). This drink could be a nutritious alternative to the existing lactose-intolerant and protein allergic, dairy-based beverages.

Volume 19, Issue 130 (December 2022)
Abstract

The health-conscious public demands high-quality and low-calorie products that are low in fat and sugar. The aim of this research is to evaluate the physicochemical characteristics of gluten-free cup cake containing inulin. In this research, rice, white bean and chia flours are used as a partial substitute for wheat flour, respectively at the levels of 50, 40 and 10 grams, inulin as a fat mimics at the levels of 0 and 30 grams, and sucralose as a partial substitute for sugar in the cake is used at the levels of 0 and 0.05 grams. According to the results of this study, sugar substitution with sucralose and fat replacement with inulin in gluten-free prebiotic cake, reduced moisture content, brighter and yellower crust and crumb, decreased pH, increased hardness and decreased springiness and cohesiveness. 

Volume 20, Issue 6 (12-2020)
Abstract

Surface deformation of the earth due to earthquake fault dislocation is very important for predicting ground motions. There are many studies on kinematic modeling of earthquake faults in both analytical and numerical methods. However, suitable investigations on improving usefulness and efficiency of those numerical methods are still necessary for relevant researchers. In this paper, displacement fields for free surface of the earth due to fault dislocation in homogeneous elastic half-space have been investigated by finite element method. Boundary conditions have significant effects on the results of finite element method, especially when the domain of the problem has infinite boundaries (half-space). Therefore, appropriate cares should be taken to increase the efficiency and accuracy of this method. In order to achieve a comprehensive study on this topic, boundaries have been modeled by two approaches here. The first approach uses common elements for infinite boundaries, while the second one uses infinite elements for those boundaries. To verify the results, each problem has been examined by several meshes and numerical solutions have been compared to Okada’s analytical solutions. In addition to the effects of the boundary modeling, the discretization effects have been investigated in order to find a suitable approach to reduce computational efforts and to increase the accuracy and efficiency of finite element method. In the modeling process, contact elements have been employed to impose fault dislocation. Three numerical examples have been provided for these finite element analyses. Each example includes four analyses without infinite elements and three analyses with infinite elements which are also compared together. The results show that not only infinite elements are necessary for quasi-static fault dislocation problems, but also they improve the performance of finite element method, so that with finer meshes and smaller dimensions of a domain, analytical solutions can be captured by numerical solutions with suitable accuracy.

Volume 20, Issue 6 (12-2020)
Abstract

Concrete is extensively used in the construction industry. To reduce the production of cement and subsequently reduce air pollution due to the release of  gas into the atmosphere and also to increase the strength of concrete, cement additives can be used. One of the additives that can be used in concrete is biochar from agricultural waste during the pyrolysis process. Pyrolysis is the process in which wastes are decomposed in the absence of oxygen and at high temperatures. Agricultural wastes are pyrolyzed before being added to concrete. It produces biofuels that can replace fossil fuels, and pyrolysis residues can be used as cement additive in concrete. In this study, the possibility of using biochar of rice husk and sugarcane bagasse treated with hydrochloric acid as an additive to replace cement at the values of 0, 5 and 10% was investigated. Sulfuric acid with pH = 1 was used to simulate the wastewater environment. In order to evaluate the effects of acidic environment on the properties of concrete samples, weight loss, compressive strength and tensile strength of the samples were measured and SEM and EDS instrumental analyzes were performed on the samples immersed in acid after 28 days.  The results showed that pretreatment of rice husk and sugarcane bagasse with dilute hydrochloric acid could improve the pozzolanic properties of the samples by reducing the amount of potassium and calcium in the composition. The results of compressive strength showed an increase in compressive strength of samples containing 5% of treated rice husk biochar and sugarcane bagasse biochar by 35.9% and 54%, respectively, compared to non-pozzolan sample (control). The changes in tensile strength of the samples containing pozzolan compared to the control sample were not significant, compared to the compressive strength. The weight and compressive strength of concrete samples decreased in the vicinity of sulfuric acid. The weight loss of all samples was less than the control, but the comparison of the compressive strength of the samples containing pozzolan with the control showed that only the compressive strength of the concrete sample containing 5% biochar of treated rice husk was higher than that of control by 16%. Tensile strength of concrete samples containing 5% biochar of treated rice husk and treated bagasse increased by 12% and 13%, respectively, compared to the control. In general, the results showed the positive effect of biochar pozzolan on the mechanical properties of concrete.

Volume 20, Issue 7 (Supplementury Issue 2018)
Abstract

The purpose of this study was to evaluate perception towards climate change, level of knowledge and climate change related behavior of agricultural professionals in Hamadan Province, Iran. The statistical population of the study consisted of 360 agricultural professionals and, by using Cochran formula, sample size was determined as 121 people, who were chosen via a simple random sampling method. Data was gathered using a structured questionnaire whose face validity was confirmed through a panel of experts and its reliability was estimated using Cronbach Alpha coefficient (above 0.70). The results revealed that mean age of sample study was almost 45 years and more than half of them had MSc. and PhD. degrees. Also, results showed that 91.7% of the respondents had strong perception, and about half of the respondents had high knowledge of climate change. While a great majority (78.5%) of the respondents was willing to join the practical efforts to mitigate effects of climate change, about one-fourth indicated they were willing to sacrifice some individual benefit to solve existing problems. The results indicated a significant (P< 1%) difference between 3 major job groups, i.e. managers, faculty members, and experts, regarding climate change related behavior. Also, correlation analysis confirmed that education level, knowledge of climate change, and perception of climate change had a significant relation with climate change related behavior.
 

Volume 20, Issue 140 (October 2023)
Abstract

The present study aims to shed light on the effects of encapsulation by the nanoemulsion (NE) method of garlic essential oil (GEO) on the oxidative stability of olive oil. To this end, the effect of different GEO percentages on NE droplet size, encapsulation efficiency, antioxidant properties, stability, and turbidity at concentrations of 200, 400, and 600 ppm was evaluated. The results showed that the droplet size of NEs ranged from 50.75 to 220.20 nm. The NEs were added to olive oil, and the oil’s peroxide, thiobarbituric acid, iodine, acid values, antioxidant properties, and sensory properties were measured at 1, 30, 60, and 90 days of storage. According to the findings, from day 30th to 90th, the lowest amount of peroxide, thiobarbituric acid, and acid values, and also the highest antioxidant activity (lowest IC50), were detected in the sample with the highest concentration of NE (600 ppm of garlic essential oil nanoemulsion [GEON] encapsulated with Arabic gum).
 

Volume 20, Issue 141 (November 2023)
Abstract

Pastilles are one of the popular and highly consumed confectionery products that raise concerns due to their low nutritional value. Therefore, the aim of this study was to examine the formulation of mango pastilles with Spirulina platensis powder and honey sweetener. The formulation ingredients included 0 to 20% mango puree, 0 to 10% honey, 5.34% gelatin, Spirulina platensis in the range of 0 to 1%, 23.38% water, 33.5% sucrose, 36.5% glucose, and 1.28% citric acid. The response surface methodology (RSM) and central composite design were used. The results showed that Spirulina platensis powder contains high amounts of protein, ash, and phenolic compounds. The three-dimensional response surface plots showed that moisture significantly increased with an increase in the amount of algae, mango, and honey. The minimum water activity was 0.2 for maximum honey and minimum mango and Spirulina. The maximum water activity was achieved for maximum mango and 8.0% Spirulina and minimum honey. With an increase in the amount of algae, mango, and honey, antioxidant activity, fat, protein, and ash content significantly increased. The highest antioxidant activity was achieved for maximum honey and Spirulina and about half of the mango. The highest firmness was recorded at 2.0% Spirulina and 0.54% mango, and the highest honey content. Firmness decreased slightly with an increase in mango and Spirulina, and then increased with a further increase in mango. The highest color was related to the highest amount of mango and the lowest amount of honey. The highest sensory acceptance was observed at 15.95% mango, 7.97% honey, and 0.80% Spirulina, and the lowest was at 4.05% mango, 2.32% honey, and 0.20% Spirulina. The results of optimizing the functional pastilles showed that the best sample was obtained at 11.67% mango powder, 2.02% honey, and 9.79% Spirulina powder.

Volume 20, Issue 141 (November 2023)
Abstract

 Today, there is a great desire to consume superfoods. Among them, foods and drinks containing probiotics and prebiotic compounds are also important. Probiotics are known as live microorganisms that balance the host's microbial flora in sufficient quantities. Most probiotic microorganisms are lactic acid bacteria such as Lactobacillus plantarum, Lactobacillus casei, Lactobacillus acidophilus and Streptococcus lactis. Inulin is a sugar compound (of the oligosaccharide type) and is indigestible or with little digestibility, it is soluble in water and has prebiotic properties, and as a source of carbon or energy, it selectively causes the growth or activity of probiotics. Cocoa milk is one of the flavored milks and high amounts of sugar are used in its formulation. Using other sweeteners as a substitute can lower the amount of calories consumed by the consumer and prevent some diseases such as diabetes and obesity. Stevia is a di-terpene glycoside, which is 300 times sweeter than sugar. In this research, stevia was used as a substitute for regular sugar and inulin as a prebiotic in the production of synbiotic cocoa milk with Lactobacillus plantarum, and 6 samples were prepared and coded; Samples include T1 (58 of stevia); T2: (%4 of stevia ); T3: (%8of inulin + %8 of sugar); T4: (%4 of inulin +%8 of sugar); T5: (%4 of stevia + %4 of inulin + 120 grams of sugar); T6: (%8 of sugar, control sample) per amount of milk consumed (3 liters of milk).The viability of probiotics, pH, acidity, Brix, viscosity, sedimentation rate and sensory evaluations of the samples were investigated on the first, third and seventh day of production. According to the results obtained from the research, samples containing inulin,especially T5 and T4 samples, had more live probiotics after 3 and 7 days of storage ....

Volume 21, Issue 1 (Spring 2017)
Abstract

Nowadays, public transportation system is known as one of the most important elements of urban development. With regard to the development of public transit services, particularly the expansion of Tehran Metro system, necessity of walkability which plays an important role is clearly and noticeable. Although Tehran’s public transportation is an urgent need, this issue has not been regarded as an important need.
TOD is a novelty and different approach of traditional theory, with considering four main principles. Accordingly in this study firstly pedestrian needs and ATRs are recognized with the use of library and archives of contexts oriented descriptive and analytical research. Secondly these needs were assessed by Quality function development and also the results of these methods prioritized by Analytic Network Process. Then these (CNs) and (ATRs) around the Tajrish station are assessed by QFD and ANP methods. As a main result the Tajrish station with the implementation rate of two-third of these criteria can be used as one of the most convenient and acceptable station for pedestrians in Tehran.

Volume 21, Issue 1 (3-2021)
Abstract

As service years increase, the corrosion of steel rebar stands out as a major problem for existing reinforced concrete (RC) structures in corrosion-inducing environment. The mechanism of steel corrosion in concrete is an electro chemical process, which is often accelerated by the ingress of aggressive chemicals, for example chloride ion. The accumulation of corrosion products on steel rebar is able to generate circular stress which could result in cover cracking. Corrosion of steel rebar will degrade the physical appearance and reduce its original cross section. Corrosion often appears to be non-uniform and localized. Corrosion damaged RC elements displayed smaller yield strength, ductility, energy dissipation capacity, etc. Corrosion level of stirrup tends to be higher than longitudinal rebar due to smaller diameter and less cover protection. Stirrup corrosion decreased confinement behaviour on concrete, thus exacerbating the degeneration of the deformation capacity and the ductility of the RC structures. The corrosion of reinforcement steel bars (rebar) is a natural electrochemical reaction RC structures have to face with. It is exacerbated by exposure to corrosion-inducing environment factors, including de-icing salt, marine salty water, carbon dioxide, sulfur dioxide, etc. The chloride from salt (NaCl) could make hazardously chemical attack on steel bar by acting as an efficient catalyst in the corrosion process. The corrosion of steel bar in the existing reinforced concrete structure has raised great concern over its safety and seismic performance among practising engineers, researchers and residents, etc., because steel bar is the most essential element in RC. Corrosion reduces the effective cross-section area of longitudinal and transverse rebars.
Due to a small concrete cover of transverse rebars compared with longitudinal rebars, the corrosion of them becomes earlier and more severe, leading to cracks in concrete, a decrease of confinement, an intensification of reduction in deformation capacity and ductility of reinforced concrete structures. For this purpose, an experimental investigation is carried out on reinforced concrete specimens include spiral and stirrup and the variables include the corrosion percentage, rebar diameter, transverse rebar pitch, and confined core diameter. Results demonstrate that the high degree corrosion has a fewer significant effect on the reduction in confinement strength, and smaller-sized transverse reinforcements are less sensitive to corrosion.

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