Journal of Science and Technology in Civil Engineering (STCE) - HUCE最新文献_第6页

Development and evaluation of short-term strength and durability characteristics of an eco-friendly sulfate-activated binder 生态友好型硫酸盐活化粘合剂短期强度和耐久性特性的开发与评价

Journal of Science and Technology in Civil Engineering (STCE) - HUCE Pub Date : 2022-01-26 DOI: 10.31814/stce.huce(nuce)2022-16(1)-05

N. Cao, Thi Hai Van Nguyen, Hoang-Tung Luu, Trong‐Phuoc Huynh

{"title":"Development and evaluation of short-term strength and durability characteristics of an eco-friendly sulfate-activated binder","authors":"N. Cao, Thi Hai Van Nguyen, Hoang-Tung Luu, Trong‐Phuoc Huynh","doi":"10.31814/stce.huce(nuce)2022-16(1)-05","DOIUrl":"https://doi.org/10.31814/stce.huce(nuce)2022-16(1)-05","url":null,"abstract":"The potential use of locally sourced ground granulated blast-furnace slag (GGBFS) and commercial sodium sulfate (Na2SO4) in the development of an eco-friendly sulfate-activated binder (SAB) was investigated in this study. The influence of Na2SO4 contents (1.5, 3.0, 4.5, 6.0, and 7.5% by mass of GGBFS) as a crucial sulfate activator on mechanical strength and durability performance of the SAB samples was evaluated through the tests of compressive strength, porosity, chloride ion penetration, and ultrasonic pulse velocity. The correlations among these properties were also established and discussed. The experimental results show that the Na2SO4 content had significant influences on both the strength and durability of the SAB samples. The porosity and chloride ion penetration were reduced as increasing the Na2SO4 content. Meanwhile, increasing the Na2SO4 content increased the compressive strength and ultrasonic pulse velocity of the SAB samples. Furthermore, the test results point out that using 7.5% Na2SO4 provided a significant improvement in the mechanical strength and durability performance of the newly developed SAB.","PeriodicalId":387908,"journal":{"name":"Journal of Science and Technology in Civil Engineering (STCE) - HUCE","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124400897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Study on dislocation cell structure, dislocation density-fatigue property relationship of a structural steel 结构钢位错胞结构、位错密度-疲劳性能关系的研究

Journal of Science and Technology in Civil Engineering (STCE) - HUCE Pub Date : 2022-01-26 DOI: 10.31814/stce.huce(nuce)2022-16(1)-03

Nguyễn Ngọc Vinh

{"title":"Study on dislocation cell structure, dislocation density-fatigue property relationship of a structural steel","authors":"Nguyễn Ngọc Vinh","doi":"10.31814/stce.huce(nuce)2022-16(1)-03","DOIUrl":"https://doi.org/10.31814/stce.huce(nuce)2022-16(1)-03","url":null,"abstract":"In this study, the evolution of the dislocation cell structure and variation of mechanical properties of structural steel under low-cycle fatigue were studied using the indentation experiment, optical microscope, and transmission electron microscope examinations. The results indicated that the dislocation cell structure was well-formed under cyclic loading. When the strain amplitude increased, the original grains were broken more, leading to the dislocation cell size tended to decrease, while dislocation density showed an increase with the further increase of strain amplitude from 0.4% to 1.0%, respectively. Both indentation hardness and yield stress tend to increase when the cyclic loading increases. The change in the dislocation structure was responsible for the strengthening of fatigue mechanical properties, meaning that the dislocation density tended to increase, while the dislocation cell size showed a decrease with the further increase of fatigue condition, leading to the increase of both hardness and yield strength since mechanical properties were inversely proportional to the mean cell size. The results of this study can be used for the practical designs as well as to understand the microstructure changes in structural steel subjected to cyclic loading.","PeriodicalId":387908,"journal":{"name":"Journal of Science and Technology in Civil Engineering (STCE) - HUCE","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117170514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Daily personal exposure to black carbon in different microenvironments in Hanoi, Vietnam 越南河内不同微环境中个人每日黑碳暴露量

Journal of Science and Technology in Civil Engineering (STCE) - HUCE Pub Date : 2022-01-26 DOI: 10.31814/stce.huce(nuce)2022-16(1)-07

T. Quang, Nguyễn Thị Huệ, Mac Van Dat, N. Duy

{"title":"Daily personal exposure to black carbon in different microenvironments in Hanoi, Vietnam","authors":"T. Quang, Nguyễn Thị Huệ, Mac Van Dat, N. Duy","doi":"10.31814/stce.huce(nuce)2022-16(1)-07","DOIUrl":"https://doi.org/10.31814/stce.huce(nuce)2022-16(1)-07","url":null,"abstract":"Daily personal exposure to black carbon (BC) in different microenvironments in Hanoi, Vietnam was quantified for the first time. In this study, a portable instrument, microAethe® model AE51, was used to continuously measure BC concentrations in various microenvironments within buildings and transportation modes. Overall average daily personal exposure to BC from those microenvironments was 5.46 µg/h. The highest BC exposure was during commuting 13.48 µg/h and 5.74 µg/h for the motorcyclist and car driver, respectively. In building environments, the highest BC exposure was 3.98 µg/h in a coffee shop with smoking; the lowest BC exposure was 1.54 µg/h in a hospital department; while BC exposure in an office was 1.92 µg/h. The level of BC exposure in an apartment was strongly influenced by building ventilation modes. They were 3.58 µg/h and 2.15 µg/h with doors/windows open and closed, respectively. Our finding confirmed that commuting contributes disproportionately to the total BC exposure due to the high level of BC during traffic/travel. Building ventilation and air conditioning can significantly affect indoor BC levels and should be considered as a measure to reduce BC exposure within buildings in Hanoi.","PeriodicalId":387908,"journal":{"name":"Journal of Science and Technology in Civil Engineering (STCE) - HUCE","volume":"176 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114077127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Experimental investigation of the secondary creep of fiber reinforced concrete at high stress: Macroscopic measurement and digital image correlation 高应力下纤维混凝土二次蠕变试验研究:宏观测量与数字图像相关

Journal of Science and Technology in Civil Engineering (STCE) - HUCE Pub Date : 2022-01-26 DOI: 10.31814/stce.huce(nuce)2022-16(1)-02

Pham-Duc Tho, Trần Mạnh Tiến, Dang Trung Thanh, Vu Minh Ngan, Vu Minh Ngoc, L. Sorelli

{"title":"Experimental investigation of the secondary creep of fiber reinforced concrete at high stress: Macroscopic measurement and digital image correlation","authors":"Pham-Duc Tho, Trần Mạnh Tiến, Dang Trung Thanh, Vu Minh Ngan, Vu Minh Ngoc, L. Sorelli","doi":"10.31814/stce.huce(nuce)2022-16(1)-02","DOIUrl":"https://doi.org/10.31814/stce.huce(nuce)2022-16(1)-02","url":null,"abstract":"The secondary creep of Fiber-Reinforced Concrete (FRC) under high sustained stress levels is a key issue for structural durability when considering the capacity to guarantee small crack widths under serviceability states. This study investigates the time-dependent deformation of FRC beams under loading level Ps/P0 greater than 80% (Ps is the load at reloading and P0 is the load before unloading) with various aggregate sizes by using both the classical macroscopic measurement and the digital image correlation analysis (DIC). Notched beams made of FRC and Fiber Reinforced Mortar (FRM) (i.e. without aggregate) were firstly pre-cracked by static load and then applied by a loading equal to 80% of strength. The evolution of the deflection, the crack width, and the crack propagation were both measured by traditional sensors and calculated by DIC. Comparison between results from FRC and FRM materials highlights the influence of microstructure heterogeneity on the secondary creep of FRC. Moreover, the DIC analysis helps to get insights on the secondary creep mechanism.","PeriodicalId":387908,"journal":{"name":"Journal of Science and Technology in Civil Engineering (STCE) - HUCE","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124503745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Effect of pre-tensioned rope tensions on a ladder structure of turntable ladders 预拉绳张力对转台梯梯结构的影响

Journal of Science and Technology in Civil Engineering (STCE) - HUCE Pub Date : 2022-01-26 DOI: 10.31814/stce.huce(nuce)2022-16(1)-12

V. Nguyen

{"title":"Effect of pre-tensioned rope tensions on a ladder structure of turntable ladders","authors":"V. Nguyen","doi":"10.31814/stce.huce(nuce)2022-16(1)-12","DOIUrl":"https://doi.org/10.31814/stce.huce(nuce)2022-16(1)-12","url":null,"abstract":"To expand the operating zone and control more precisely, it is vital to enhance the flexural stiffness of the ladder structures of turntable ladders. Based on one set of optimized 3-segment ladders, the author proposed a solution to increase the bending stiffness on each ladder while their mass hardly increases. Steel wire ropes are suggested to be added inside the handrails. They are pre-stretched and controlled to reduce the vertical displacement and rapidly quench oscillation at the ladder top. These benefits have been demonstrated in the dynamic aspect in other works. In this study, the effect of pre-tensioned rope tensions on ladder structure is investigated and evaluated according to current standards. The work includes modeling the ladder structure, defining loads, combining loads, investigating stresses and displacements according to the tension values. Afterward, the positive effects and negative influences, as well as the recommendations on tension load and tensile process, are presented. According to the obtained results, the structure still ensures the working conditions while the tension value reaches the maximum one. Most of the stress values in the structural elements decrease with increasing tension. The vertical displacement at the top decreases significantly.","PeriodicalId":387908,"journal":{"name":"Journal of Science and Technology in Civil Engineering (STCE) - HUCE","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125111480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

A proposed method for selecting and scaling recorded seismic accelerations according to TCVN-9386:2012 根据TCVN-9386:2012，提出了一种选择和标度记录地震加速度的方法

Journal of Science and Technology in Civil Engineering (STCE) - HUCE Pub Date : 2022-01-26 DOI: 10.31814/stce.huce(nuce)2022-16(1)-09

X. Nguyen, Van Tu Nguyen

{"title":"A proposed method for selecting and scaling recorded seismic accelerations according to TCVN-9386:2012","authors":"X. Nguyen, Van Tu Nguyen","doi":"10.31814/stce.huce(nuce)2022-16(1)-09","DOIUrl":"https://doi.org/10.31814/stce.huce(nuce)2022-16(1)-09","url":null,"abstract":"Accelerogram is a significant input in seismic analysis of structures, particularly for performance-based seismic designs and for advanced technologies using nonlinear energy dissipation devices. However, in seismic regions like Vietnam, earthquake data is generally scarce. Vietnam Standard TCVN-9386:2012 mentions the use of recorded accelerogram for seismic analysis, although it contains shortcomings. The paper aims to detail the procedure of selecting and scaling recorded seismic accelerations according to requirements specified by TCVN-9386:2012. The target response spectrum and the fundamental vibration period of the considered structure are critical factors for the selecting and scaling process. The proposed procedure essentially includes converting the two original horizontal accelerations to the principal directions, correcting the relative proportion between the two acceleration components, determining the period range of interest, calculating the scaling factors, and verifying the 10% matching criteria. An example is conducted on a typical set of accelerations to detail the application of the proposed procedure. The results show that the response spectra of calibrated accelerations are consistent with the target spectrum and satisfy the requirements of TCVN-9386:2012, suggesting that the proposed method can be applied to the seismic analysis of structures with high reliability.","PeriodicalId":387908,"journal":{"name":"Journal of Science and Technology in Civil Engineering (STCE) - HUCE","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134509949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Effect of paste content on long-term strength and durability performance of green mortars 膏体掺量对绿色砂浆长期强度和耐久性的影响

Journal of Science and Technology in Civil Engineering (STCE) - HUCE Pub Date : 2022-01-26 DOI: 10.31814/stce.huce(nuce)2022-16(1)-10

Si-Huy Ngo, Trong‐Phuoc Huynh

{"title":"Effect of paste content on long-term strength and durability performance of green mortars","authors":"Si-Huy Ngo, Trong‐Phuoc Huynh","doi":"10.31814/stce.huce(nuce)2022-16(1)-10","DOIUrl":"https://doi.org/10.31814/stce.huce(nuce)2022-16(1)-10","url":null,"abstract":"This study uses densified mixture design algorithm (DMDA) to design the mixture proportions green mortars incorporating fly ash and ground granulated blast furnace slag (GGBFS). Three green mortar mixtures with various paste contents were designed using the DMDA method while a control cement-based mortar mixture was designed using the conventional method for comparison. The effect of different paste contents (n = 1.1, 1.3, and 1.5) on the changes of porosity, thermal conductivity, compressive strength, chloride ion penetration, resistance to sulfate attack, and ultrasonic pulse velocity (UPV) of both the green and control mortars was studied. The procedures of DMDA mix design for green mortar mixtures were also presented in this study. Test results reveal that all three green mixtures show a better performance than the control mixture, especially for long-term properties. On the other hand, increasing paste content increased porosity and compressive strength, however, it reduced thermal conductivity and UPV of the green mortars. All of the green mortars exhibited good performance with low porosity and compressive strength values of above 40 MPa after 28 days of curing. Moreover, the green mortars also demonstrated excellent ability to resist chloride (with RCPT values significantly lower than the threshold of 1000 coulombs) and sulfate attacks. As a result, the quality of these mortars was classified as very good level with UPV values of above 4000 m/s. This study proves the effectiveness of using the DMDA method to design the green mortar mixtures in the combination of using fly ash and GGBFS.","PeriodicalId":387908,"journal":{"name":"Journal of Science and Technology in Civil Engineering (STCE) - HUCE","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127644658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Effect of prestressing force on flexural behavior of unbonded prestressed concrete beams strengthened by CFRP sheets 预应力对CFRP布加固无粘结预应力混凝土梁抗弯性能的影响

Journal of Science and Technology in Civil Engineering (STCE) - HUCE Pub Date : 2022-01-26 DOI: 10.31814/stce.huce(nuce)2022-16(1)-01

Dang Dang Tung, Chunchao Tu, Huynh Thi Kim Phung, N. Long

{"title":"Effect of prestressing force on flexural behavior of unbonded prestressed concrete beams strengthened by CFRP sheets","authors":"Dang Dang Tung, Chunchao Tu, Huynh Thi Kim Phung, N. Long","doi":"10.31814/stce.huce(nuce)2022-16(1)-01","DOIUrl":"https://doi.org/10.31814/stce.huce(nuce)2022-16(1)-01","url":null,"abstract":"This paper presents an experimental study on the effect of prestressing force on the flexural behavior of unbonded prestressed concrete (UPC) strengthened by Carbon fiber reinforced polymer (CFRP) sheets. The testing program was carried out on nine large-scale UPC rectangular beams. The investigated parameters included the reduction of prestressing force (0%, 15%, and 30%) and the number of CFRP layers (0, 2, and 4 layers). Experimental results showed that the strengthening effectiveness of CFRP sheets, controlling cracking, and the energy absorption capacity tended to increase with the decrease of prestressing force and decrease with the increase of the CFRP sheets ratio. The effective performance of the CFRP sheets was shown by the increase in the strain of the CFRP sheets which was proportional to the decrease in the prestressing force. The CFRP sheets strongly interacted with tendons, significantly decreased the tendon strain, and delayed the point where nominal yield strain in tendons occurred; this reduction was significant when the prestressing force was small. Besides, the reduction in prestressing force considerably increased the displacement of beams and the additional strain of the tendons (up to 164%), but this increase became smaller as the number of CFRP layers increased.","PeriodicalId":387908,"journal":{"name":"Journal of Science and Technology in Civil Engineering (STCE) - HUCE","volume":"81 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121042304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Study on the mechanism of urban planning information exchange to enhance the community participation in urban detailed planning in Vietnam – towards sustainable development 促进越南城市详细规划社区参与的城市规划信息交流机制研究——走向可持续发展

Journal of Science and Technology in Civil Engineering (STCE) - HUCE Pub Date : 2022-01-26 DOI: 10.31814/stce.huce(nuce)2022-16(1)-04

T. Q. Hoa

{"title":"Study on the mechanism of urban planning information exchange to enhance the community participation in urban detailed planning in Vietnam – towards sustainable development","authors":"T. Q. Hoa","doi":"10.31814/stce.huce(nuce)2022-16(1)-04","DOIUrl":"https://doi.org/10.31814/stce.huce(nuce)2022-16(1)-04","url":null,"abstract":"This paper explores the extent of the current mechanism to access urban spatial planning information of community in urban detailed planning projects (UDPPs), the constraints on urban planning information accessibility in Vietnam context to challenge the community participation for sustainable development. The research is based on an analysis of the planning information sharing content found in four UDPPs in Vietnam and interviews with 20 key informants. The research identified that the urban spatial planning information for the community is limited and difficult to access, and the planning information exchange process is one-way flow, authority-controlled and non-transparent. Besides, the lack of human resources and technological application provide a challenging context for involving the community in UDPPs. The paper concludes by proposing several recommendations for improving the urban planning information exchange process and technological tools that should be applied to foster community participation in Vietnam's urban context, towards sustainable development.","PeriodicalId":387908,"journal":{"name":"Journal of Science and Technology in Civil Engineering (STCE) - HUCE","volume":"120 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128018942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Buckling analysis of functionally graded sandwich plates resting on Pasternak foundation using a novel refined quasi-3D third-order shear deformation theory 基于准三维三阶剪切变形理论的Pasternak地基功能梯度夹层板屈曲分析

Journal of Science and Technology in Civil Engineering (STCE) - HUCE Pub Date : 2022-01-26 DOI: 10.31814/stce.huce(nuce)2022-16(1)-06

Vu Tan Van, N. Hieu

引用次数: 1