Limiting Reinforcement Ratios for Hybrid GFRP/Steel Reinforced Concrete Beams

In this work, a theoretical approach is proposed for estimating the minimum and maximum reinforcement ratios for hybrid glass fiber reinforced polymer (GFRP)/steel-reinforced concrete beams to prevent sudden and brittle failure as well as the compression failure of concrete before the tension failure of reinforcements. Equilibrium equations were used to develop a method for determining the minimum hybrid GFRP/steel reinforcement ratio. A method for determining the maximum hybrid GFRP/steel reinforcement ratio was also developed based on the equilibrium of forces of the balanced failure mode. For estimating the load-carrying capacity of concrete beams reinforced with hybrid GFRP/steel, less than the minimum and more than the maximum reinforcement ratio is recommended. Comparisons between the proposed expressions, experimental data, and available test results in the literature shows good agreement between the theoretical and experimental data, with a maximum discrepancy of 7%

Experimental and Theoretical Analysis of Cracking Moment of Concrete Beams Reinforced with Hybrid Fiber Reinforced Polymer and Steel Rebars

This study aims at experimentally and theoretically investigating the cracking moment (Mcrc) of hybrid Fiber Reinforced Polymer (FRP)/steel Reinforced Concrete (RC) beams. Six hybrid Glass FRP (GFRP)/steel and three GFRP RC beams with various GFRP and steel reinforcement ratios are tested in four-point bending scheme. Experimental results indicate that both GFRP and steel rebars affect Mcrc, but the effect of steel reinforcement is more significant. When the steel reinforcement ratio increases to 1.17%, Mcrc goes up to 15.9%, while the same value for GFRP is only 9.7%. An analytical method is proposed based on the plain section assumption and nonlinear behavior of materials for estimating Mcrc. The proposed model shows a good agreement with the experimental data conducted in this study and collected from the literature. The results of the parametric study give evidence of the positive effects of hybrid reinforcement ratios and elastic modulus of FRP on Mcrc of hybrid RC beams

The Organizational Structure of the Securities Company Under the Law of Vietnam Current

Purpose: The article researches on the organizational structure of securities company under the Securities Law 2019 in order to point out some limitations and shortcomings and propose for recommendations to improve law about organizational structure on this form of company.   Theoretical framework: Recent literature points out that securities companies play very important role in the development of Vietnam's stock market. However, in the current stage of development, from the influence and impact of international integration and the increasingly fierce competitive pressure, the securities companies have encountered many difficulties to survive. In there, limits and problems in regulations about securities company organizational structures has caused many difficulties for these companies when organization and operation. On the other hand, in the context of judicial reform in Vietnam, the issue of complete law system and expanding the freedom to business has always been paid special attention by the Party and Vietnam State.   Design/methodology/approach: The authors have combined traditional research methods of legal science such as legal analysis method, legal efficiency assessment method and legal comparison method.   Findings: According to research, regulations on the organizational structure of a securities company are directly related to the efficiency of management and administration of this company. In there, Supervisory Board/Internal Audit Committee always ensuring to limit negative and fraudulent acts of the company’s leaders, to better ensure the legitimate rights and interests of the company's members and customers. Therefore, the authors have proposed several solutions such as the need to stipulate the mandatory requirement of a Supervisory Board for the securities trading company under the model of limited liability company, and expand and strengthen the powers of the Supervisory Board/Internal Audit Committee, independent members in securities companies doing business in the form of joint stock company. These are important bases to contribute to perfecting the Law on the organizational structure of securities companies in Vietnam and further enhancing the stability and safety of the Vietnamese stock market.   Research, Practical & Social implications: This research may support many develop future research in Vietnam. At the same time, the research to help foreign investors' activities in Vietnam's stock market.   Originality/value: The research of the freedom to business and organizational structure of securities companies become more and more urgent and very important in Vietnam

Cooperative Group In Current Vietnamese Commercial Environment

Purpose: The article researches the compatibility between the cooperative group and the current commercial environment in Vietnam to propose for improvement to the laws and for promotion of development of the cooperative group.   Theoretical framework: Recent literature points out that the cooperative group model is quite suitable for the production and business psychology of citizens in Vietnam. In the current stage of development, however, from the influence and impact of international integration and the increasingly fierce competitive pressure of various types of enterprises, the cooperative group have encountered many difficulties to survive. On the other hand, in the context of judicial reform in Vietnam, the issue of complete law system and expanding the freedom to business has always been paid special attention by the Party and Vietnam State.   Design/methodology/approach: The authors have combined traditional research methods of legal science such as legal analysis method, legal efficiency assessment method and legal comparison method.   Findings: According to research, the cooperative group is well adapted to Vietnam's commercial environment because it is compatible with investor psychology and meets the conditions and circumstances of nature, economy and society. However, since Vietnam's deep integration with the rest of the world, the cooperative group model has faced numerous difficulties and challenges, and if suitable solutions are not found, it is very likely that this collective economy will become increasingly difficult. As a result, the article suggests some important solutions, such as offering cooperative group legal status and requiring more preferential lending policies with long loan terms, simple and quick loan procedures, and easy team cooperation.   Research, Practical & Social implications: This research may support many develop future research in Vietnam.   Originality/value: The study of the freedom to business become more and more urgent and very important in Vietnam

Experimental study of short concrete columns reinforced with GFRP bars under monotonic loading

The glass fiber reinforced polymer (GFRP) bars are considered as an alternative reinforcement to steel in concrete structures subjected to chloride environment because of their non- corrosive and non-magnetic properties. To examine the applicability of GFRP bars to performance of concrete columns, this work was conducted. The effect of the compressive reinforcement ratio and stirrup spacing on the load carrying capacity of concrete columns reinforced with GFRP bars is experimentally investigated. Nine short concrete columns with dimensions of 150 × 150 × 600 mm were cast and tested until failure under displacement-controlled concentric loading. The experimental results demonstrated that by increasing the reinforcement ratio from 0.37% to 3.24%, the load-bearing capacity of GFRP RC columns was found to increase by an average of 28%. Moreover, the tested results confirmed that the GFRP stirrup spacing had a significant influence on the load-carrying capacity of the columns

Experimental study of short concrete columns reinforced with GFRP bars under monotonic loading

The glass fiber reinforced polymer (GFRP) bars are considered as an alternative reinforcement to steel in concrete structures subjected to chloride environment because of their non- corrosive and non-magnetic properties. To examine the applicability of GFRP bars to performance of concrete columns, this work was conducted. The effect of the compressive reinforcement ratio and stirrup spacing on the load carrying capacity of concrete columns reinforced with GFRP bars is experimentally investigated. Nine short concrete columns with dimensions of 150 × 150 × 600 mm were cast and tested until failure under displacement-controlled concentric loading. The experimental results demonstrated that by increasing the reinforcement ratio from 0.37% to 3.24%, the load-bearing capacity of GFRP RC columns was found to increase by an average of 28%. Moreover, the tested results confirmed that the GFRP stirrup spacing had a significant influence on the load-carrying capacity of the columns

The Correlation between the Structures of the Nasal Tip on the Ultrasound and the Anthropometry of the Nose in Vietnamese

BACKGROUND: Nowadays, there are few types of research held in Vietnam to investigate the anthropometric index of the nose as well as analysis the structure of nasal tip on ultrasound to identify the relationship between these parameters. AIM: determine the relationship between the height and the width of the nasal tip and the structures constructed these areas by anthropometric and ultrasound measurement. METHODS: a descriptive study in Thanh Van Hospital from December 2017 to April 2019. RESULTS: There were 94 women (62.7%), and 56 men (37.3%) and the average age were 33.6 years old. The height and width of the nasal tip are 10.1 mm and 21.7 mm, respectively. Through the ultrasound, the thickness of the adipose tissues is 3 mm. The width of the interdomal fat pad is 6.5 mm and the distance between two tip point is 5.6 mm. There are the relationships between the distance of two tip points and the width of the tip (r = 0.341), and the width of the interdomal fat pad (r = 0.72). There is also the correlation between the width of the nasal tip with the distance of two tip points (r = 0.46) and the height of the tip with the thickness of the interdomal fat pad (r = 1.23). CONCLUSION: The thickness of the interdomal fat affects the height of the tip, and the distance of two tip points influences the width of the tip