Journal of Science and Technology in Civil Engineering

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.

13p haoasakura 30-05-2022 14 2   Download

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).

10p haoasakura 30-05-2022 10 1   Download

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.

15p haoasakura 30-05-2022 10 1   Download

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.

11p haoasakura 30-05-2022 12 2   Download

This study proposes applying cold-bonded low calcium Class F fly ash (FFA) based artificial lightweight aggregate (ALWA) to partially replace natural fine aggregate in an ecological unfired brick with a low energy super-sulfated cement (SSC). To estimate the influence of ALWA on the brick properties, natural fine aggregate (FA) in the reference brick was substituted with ALWA at four different amounts of 25, 50, 75 and 100% by volume.

12p haoasakura 30-05-2022 8 2   Download

This study proposes an alternative approach based on the deep learning paradigm working in a complementary way with conventional methods such as the finite element method for quickly forecasting the responses of structures under random wind loads with reasonable accuracy. The approach works in a sequenceto-sequence fashion, providing a good trade-off between the prediction performance and required computation resources.

11p haoasakura 30-05-2022 32 2   Download

In this study, the effect of polyvinyl alcohol (PVA) content, i.e. from 2 to 6% by vol. of concrete, on the flexural behavior of ECC with a desired compressive strength of over 60 MPa, in which fly ash and silica fume were selected as supplementary cementitious materials. The experimental results show that the addition of PVA fiber gives little influence on compressive strength but can significantly affect the flexural behavior of ECC.

10p haoasakura 30-05-2022 32 2   Download

This study presents a numerical model for buckling analysis of the functionally graded sandwich plates (FGSP) laid on the elastic foundation through the Moving Kriging interpolation-based meshless method using a refined quasi-3D third-order shear deformation theory.

12p haoasakura 30-05-2022 9 1   Download

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.

9p haoasakura 30-05-2022 15 1   Download

This study attempts to develop a numerical scheme for 2-D transient analysis under unsaturated conditions. First, the unsaturated groundwater flow was described using the mass conservation law. Then, the Finite Difference Method and Backward Euler approximation were applied for space and time discretization, respectively.

11p haoasakura 30-05-2022 9 1   Download

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.

13p haoasakura 30-05-2022 8 1   Download

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.

13p haoasakura 30-05-2022 13 1   Download

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.

14p haoasakura 30-05-2022 8 1   Download

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).

18p haoasakura 30-05-2022 8 1   Download

The paper presents experimental results and structural analysis of reinforced concrete (RC) columns made of recycled aggregate concrete (RAC) and natural aggregate concrete (NAC) under concentric compressive load. The ratio of recycled aggregates in mixture (i.e, replacement ratio, r in %) was 0, 50, and 100% by mass, where r = 0% corresponding to NAC.

11p haoasakura 30-05-2022 9 1   Download

This paper, therefore, set out to find the influence of the microfines on the performance of concrete by determining its effect on the slump, the water demand, and compressive strength of concrete with microfines from 1 to 6% at 1% increment of the weight of fine aggregates. Experimental results showed that microfines in concrete could affect the slump and water demand for concrete minimally.

10p haoasakura 30-05-2022 10 1   Download

This paper aims to apply the developed ADE to optimize truss structures subjected to frequency constraints. In addition, limitations of the AOA are also discussed, as well as how to overcome them. In each iteration, a randomly generated probability parameter is used to determine whether AOA or DE that would be used to generate new candidate solutions in the population.

16p haoasakura 30-05-2022 11 1   Download

This study aims to use FA and GGBFS to replace 50% cement in the production of LFC. Various PP fiber contents were also incorporated to enhance the mechanical strength of LFC. Then, the influence of PP fiber content on the engineering properties of LFC was investigated in terms of fresh unit weight (UW), dry density, water absorption, thermal conductivity, flexural strength, compressive strength, and ultrasonic pulse velocity (UPV).

12p haoasakura 30-05-2022 23 1   Download

In this paper, by replacing a part of heavy (high stiffness) particles with light (low stiffness) particles, we numerical investigate the effects of lightweight particle content on the mechanical strength of wet cylindrical agglomerates under uniaxial compression test. To simplify the model, the deformable characteristics of lightweight particles are neglected, implying that all particles are modeled as rigid grains.

11p haoasakura 30-05-2022 20 1   Download

The paper proposes several recommendations for improving planning codes and standards of small public spaces, planning and landscape architecture in existing small public spaces in the inner city of Hanoi, and collaborative mechanisms among different stakeholders toward sustainable development.

17p haoasakura 30-05-2022 32 1   Download