Journal of Materials and Engineering Structures

519-524

Authors: Farid ASMA, Hocine HAMMOUM

The year 2020 has been a difficult one for most of us; the coronavirus pandemic has not only affected our health and sanity, but has also had a lasting impact on our lives. Now as we enter the year 2021, the Journal of Materials and Engineering Structures (JMES) would like to wish you all a very happy and prosperous New Year. We appreciate the contributions and support from around the world to develop and improve JMES publications. We have received the complete trust and gratitude of the authors in the research communities; we promise to do the best we can not only to maintain the scientific excellence of JMES, but also to continue work to improve the best publication practices. This special issue of Journal of Materials and Engineering Structures (JMES) includes manuscripts of some of the presentations at the third International Conference on Sustainability in Civil Engineering (ICSCE 2020), held during 26-27 November, 2020 at Hanoi, Vietnam. We believe that all the papers published in this special issue will be an opportunity for researchers to present recent works on Sustainability in Civil Engineering field. The International Conference on Sustainability in Civil Engineering is very significant to the development of new ideas and the promotion of research into advanced in Sustainability in Civil Engineering field. ICSCE 2020 received more than 200 abstracts and 135 full paper were submitted and 23 were selected for publishing, from all over the world have been rigorously reviewed before being accepted for this special issue. According to their subject and their merit by professionals, twenty three of the best papers presented at the ICSCE 2020 Conference are included in the issue, from six different countries (Vietnam, Japan, Portugal, China, Australia and Malaysia). The two first papers are keynote speakers. The first paper aims to improve the use of recycled aggregates prepared using the aggregate replacement method, reducing both the environmental burden and costs associated with concrete waste. The second paper gives a focus on the recent developments on the assessment and forecasting the performance of bridge and other structures including an overview of the different types of structures, especially those related to transportation infrastructure. Some papers deal with the subject of durability relating to different themes of civil engineering, such as the performance of concrete reinforced with FRP, Properties of polymer concrete used for repairing portland cement and recycled concrete aggregate by cement. Other topics, as important as they are diverse are also discussed in this issue such as prestressed concrete, steel corrosion, asphalt pavement,... We would like to thank all the authors who contributed to this special issue. Below you will find important information on the Third International Conference on Sustainability in Civil Engineering, such as the purpose and scope and the main themes of ICSCE 2020.

551-559

Authors: José C. Matos, Sérgio Fernandes, Hélder S. Sousa, Mário Coelho, Elisabete Teixeira, Yina Moscoso, Joaquim Tinoco

The process of managing a stock of existing bridges and structures is extremely complex and challenging. At the same time, it is considered as one of the most relevant and important fields for civil engineers, involving academics, researchers, consultants, contractors, and owners. Indeed, in the recent years, several national and international R&D funded projects raised this topic, and many international associations, such as EuroStruct, IABSE& fib, started commissions and task groups on this field. This work consists on an overview of the most recent matters on this field, covering the whole cycle, from the quality control, addressing extreme events, to the decision making process. Also, it will be given a focus on the recent developments on the assessment and forecasting the performance of bridge and other structures. Finally, an overview will be made for different types of structures, specifically those related to transport infrastructures.

567-574

Authors: Duy Hoa Pham, Ba Danh Le, Dang Tung Khuc, Thanh Quang Vu, Trong Toan Khong, Van Trinh Do, Quy Tuan Ngo

The objective of this paper is to investigate the bond properties of prestressing strands embedded in Ultra–High–Performance Concrete (UHPC).The UHPC was made in laboratory using local materials in Vietnam.Its mixture contains: silica aggregates, portland cement PC40, fly ash, silica fume, polycarboxylate superplasticizer and the micro steel fibers.The experimental process is realized on a pull-out test. The volume fraction of micro steel fibers in UHPC was 2%. The prestressing strand with diameters of 15.2mm was considered. The interface shear strength between strand and UHPC is identified based on the results of force and displacement obtained during the pull-out test. The Cohesive Zone Model (CZM) is implemented in finite element model to study this interface behavior. This model described by a piecewise linear elastic law. The CZM’s parameters are identified based on experimental results of pull-out test.The numerical studies are used the CZM in ANSYS software. Two numerical tests are realized and compared with experimental results: pull-out test and other test to verify the deflection of I girder due to prestressing force.

583-589

Authors: Pham Huy Khang, Nguyen Trong Hiep

Polymer concrete (PC) is a popular construction material used for repair, thin overlays for floors and bridge decks, and other specialized fields such as precast components, machine construction. The material has many desirable properties such as fast curing, high compressive and flexural strength, high bonding to substrate, resistance to chemical agents. This study focuses on finding the suitable PC content oriented for repairing works of airfield Portland cement concrete (PCC) pavement. An experimental program was designed to investigate the mechanical properties of PC mixtures with polymer resin and filler contents varied in the ranges of 12-22 wt. % and 0-20 wt. %, respectively. The tests were conducted in accordance with the Vietnam standards system, for all samples at 2-hour-age and room condition. The test results showed that the highest values of compressive and flexural strengths and elastic modulus were 95.9 MPa, 18.7 MPa, and 37.8 GPa, respectively, at the same mixture of 22 wt. % polymer binder and 20 wt. % filler content. For samples of more than 18 wt. % of polymer binder, the direct pull-off tests demonstrated that the PC perfectly bonded to the existing PCC, with all failure locations occurred in PCC substrate. The abrasion test showed that all PC mixtures has lost only less than 0.09 g/cm2, about one-third of regulated value for airfield pavement.

597-603

Authors: Nguyen Phuong Duy, Tran Duc Lan

Wind induced vibrations are considering as one of the major concerns of the owner, the engineers and contractors of stay cable bridges. This paper presents in premier lieu the assessment of the vibration monitoring data from the pre-installed accelerometers on the longest cables of the Bach Dang bridge, Quang Ninh province. The identified cables natural frequencies based on the ambient vibration monitoring data were then compared to the taut string vibrating model calculation based on lift-off tension forces showing a good concordant. The enhanced damping of the cables stayed were then estimated and compared to the damping test results of another stay cables bridge recently performed in Vietnam with similar range of cables length. The damping prediction are quite in line with the damping test results and comparable also to those given in most of International Standard for stay cable. Finally, the identified natural frequencies and predicted intrinsic damping were used for an assessment of the wind induced vibration instability including the wind/rain induced vibration, wake galloping and vortex excitation.

613-618

Authors: Tran Anh Dung, Le Hai Ha, Tran The Truyen, Nguyen Hong Phong

Highway-railway grade crossings are an important part of the transportation system. It allows two types of vehicles to operate in the same areas. Researchers have previously studied the grade crossings, but research on the monolithic prestressed concrete slab (PSCS) track at grade crossings for 1,000mm gauge is limited. At present, there are many types of grade crossing structures that are using in Vietnam. However, these structures still have many disadvantages in the operation process. A new structure type of grade crossing for PSCS is proposed to apply for the 1,000 mm gauge to overcome the main disadvantages of existing structural types. This paper presents test production and experimental measurements to analyze the behavior of PSCS. Test samples of monolithic PSCS were produced in factory. Measurement experiments were conducted in the laboratory. The results of the manufacturing and testing process presented in this paper show that this structure completely meets the criteria of stability and durability under the effect of test loads.

627-632

Authors: Huu-Dao Do, Van-Ngoc Pham, Anand J. Puppala, Duc-Manh Nguyen

The paper presents the vertical bearing capacity of bored piles from the bi-directional load test (O-Cell method) at the Tra Khuc dam-bridge project in Quang Ngai province. The dam structure was supported by approximately 400 bored piles with the diameter of D1200 mm and the length of 27 m to 50 m. The ground includes the sand, clay and weathered rock layers with the SPT index (N30) from 8 to 80. The pile's tips were socketed in the granite layer with the average compressive strength of 18.6 MPa. Two test piles with the length of 29.1 m (T1N) and 42.75 m (T8N) were conducted O-Cell test. The side friction of soil layers and pile tip resistance were analyzed. The axial strain obtained from strain gages were used to analyze the axial load distribution along the depth of the pile. The test results show that the side resistance of the piles in the weathered rock mixed is 77.14 kPa for the pile T1N and 72.34 kPa for the pile T8N (approximately 50% of the total side resistance) which are not the ultimate shaft resistance of the piles in this layer. As its’ advantages, the bi-directional load test could be applied widely in the narrow site or on river condition in Vietnam.

639-644

Authors: Ji Chen, Bangyao Zhong, Jianxin Yang, Xuenan Zheng, Xuegang Zhu, Qiang Tang

Pipe jacking construction in complex soil layers and soil conditions remains to be a tough issue, because various factors are supposed to be considered and the jacking parameters needs optimization. The purpose of this paper is to analyze the impact of pipe jacking on surface settlement, soil deformation and pipe-soil interaction in a numerical model of pipe jacking through deep soft soil, which is a simulated construction of urban underground sewage pipeline. The results show that the pipe jacking construction adopted in the deep soft soil layer has little effect on the surrounding soil layers. And the maximum ground settlement is only about 8 mm. The impact of pipe jacking construction in deep soft soil layer on ground settlement is about 6 times the diameter of the jacking pipe along the pipe axis. Finally, the input force needs to be selected according to the condition of the soil layer to ensure the safety of the pipe jacking construction.

651-658

Authors: Phe Van Pham, Xuan Huy Nguyen

Elastic and inelastic moment resistances of W-steel beams with considering the effects of initial imperfections and residual stresses are numerically investigated in the present study. The numerical model is implemented in ABAQUS in which residual stresses are incorporated by using initial conditions while the initial imperfection is imported through the first lateral-torsional buckling mode. By comparing the FEA moment resistances of W250x45 steel beams against those of the CSA S16 and Eurocodes 3 design standards, it is observed that (i) If the effects of initial imperfections and residual stresses are excluded, the inelastic resistances are close to a fully plasticized section moment. In contrast, if the effects are included, the inelastic resistances are significantly smaller than the fully plasticized moment. (ii) The effects of initial imperfections on the moment resistance are significant for intermediate and long spans. Although the initial imperfection taken in the present study is 4.0 mm, that is within the allowable limit specified in the design standards (i.e., not greater than L/1000), the moment resistances with the taken imperfection are considerably smaller than the design moments specified in the design standards, and (iii) When considering steel beams with the effects of initial imperfection and residual stresses, the moment resistances based on the CSA S16 and EC3-6.3.2.3 solutions are higher, while those based on EC3-6.3.2.2 solution are lower than the moment capacities of the beams with the initial imperfection. This indicates that EC3-6.3.2.2 clause is the most safety design for the moment resistances.

669-675

Authors: Huynh Xuan Tin, Nguyen Trung Truc, Tran Tri Quang, Ngo Thanh Thuy

The experiment consists of twenty-four mid-scale rectangular RC columns (200x200x800mm) strengthening by BFRP sheets and research variables include: BFRP layer (0, 1, and 3 layers); eccentricity (25mm and 75mm); and 4 levels of steel corrosion. The results reveal that SEL (ratio of ultimate load of strengthened member to that of corresponding controlled member) is direct proportion with steel corrosion while SEV (ratio of ultimate vertical displacement of strengthened member to that of corresponding controlled member) is inverse proportion with steel corrosion; SEL slightly increases with the increase of BFRP layer and eccentricity; but SEV decreases noticeably with the increase of BFRP layer and eccentricity. In addition,the interaction between FRP sheets, stirrups, and longitudinal reinforcement in steel degraded BFRP strengthened columns is very strong.However, column design basing on current design manuals and codes as ACI 440.2R and CNR DT 200R1 has not mentioned this affect. Thus, the load capacity prediction of column being strengthened by BFRP sheets should include levels of steel corrosion for reality, reasonable, and integral of the design.

685-693

Authors: Nguyen Anh Duc, Dosho Yasuhiro, Nishikigi Kenji, Dinh Van Linh

Since the 19th century, concrete has been a fundamental construction material. It is the most popular manmade material in the world because of its more reliable workability, greater durability, and lower cost compared with other construction materials. However, because of its durability, demolishing or renovating old structures generates a huge amount of concrete waste, which, if not properly treated or reused, can adversely affect the environment. Therefore, the development of concrete-recycling technology is a necessary and pressing requirement for all the countries. This study concerns material design with concrete using low-quality recycled aggregates prepared via an aggregate replacement method. To evaluate the quality of the aggregates in recycled aggregate concrete, experiments were conducted using specimen groups characterized by various mix proportions. Accordingly, when low-quality recycled aggregate is used, by employing the relative quality index method for material design, the manufacturing of recycled aggregate concrete with required performance could be achieved.

703-710

Authors: Nguyen Thi Cam Nhung, Tran Quang Minh

Many construction activities such as pile driving, drilling, roadbed compaction, drilling and blasting tunnels can cause ground vibration, which affects buildings and people nearby. If the wave intensity is high while the distance to neighboring buildings is close, the presence of damage in buildings is inevitable. Determination of the vibration radius which can cause damage in surrounding structures regarding each source of vibration is a necessary requirement for planning, construction technology selection and design method. It can minimize risks to surrounding buildings. The content of this article presents the measurement method to accurately estimate the vibration level of the construction activities of Hanoi pilot urban railway line 3 passing the busy Kim Ma street, Hanoi. High sensitivity vibration accelerometers are gathered in lines from the vibration source. It is shown that predicting the radius of the impact of construction site vibrations to neighboring buildings is possible. If the level of vibration is high then measures can be taken to prevent damage caused by the construction of the Hanoi pilot urban railway line. From obtained results, some solutions are proposed to minimize and avoid possible negative impacts.