Abstract
Tensile property is one of the excellent properties of ultra-high performance concrete (UHPC), and uniaxial tensile test is an important and challenging mechanical performance test of UHPC. Traditional uniaxial tensile tests of concrete materials have inherent defects such as initial eccentricity, which often lead to cracks and failure in non-test zone, and affect the testing accuracy of tensile properties of materials. In this paper, an original integrated design scheme of mould and end fixture is proposed, which achieves seamless matching between the tension end of specimen and the test fixture, and minimizes the cumulative eccentricity caused by the difference in the matching between the tension end of specimen and the local stress concentration at the end. The stress analysis and optimization design are carried out by finite element method. The curve transition in the end of specimen is preferred compared to straight line transition. The rationality of the new integrated design is verified by uniaxial tensile test of strain hardening UHPC, in which the whole stress-strain curve was measured, including the elastic behavior before cracking, strain hardening behavior after cracking and strain softening behavior.
Key Words
finite element analysis; mould integration; uniaxial tension; ultra-high performance concrete; test fixture
Address
Xiaochen Zhang and Josue G. Mitobaba: School of Civil Engineering, Harbin Institute of Technology, Harbin, 150090, China
Chao Shen: Shanghai Fengling Renewables Co., Ltd. Shanghai 200021, China
Xuesen Zhang: CGN New Holdings Co., Ltd, Beijing 100070, China
Xiangguo Wu: College of Civil Engineering, Fuzhou University, Fuzhou, 350108, China/ Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education, Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of the Industry and Information Technology, Harbin Institute of Technology, Harbin, 150090, China
Qiu Faqiang: JianYan Test Group Co., Ltd, Xiamen 361004, China
Abstract
Due to their natural and social revelation, also their ease and flexibility, human collective behavior and teamwork sports are inspired to introduce optimization algorithms to solve various engineering and scientific problems. Nowadays, meta-heuristic algorithms are becoming some striking methods for solving complex real-world problems. In that respect in the present study, the authors propose a novel meta-innovative algorithm based on soccer teamwork sport, suitable for optimization problems. The method may be referred to as the Soccer League Optimization-based Championship Algorithm, inspired by the Soccer league. This method consists of two main steps, including: 1. Qualifying competitions and 2. Main competitions. To evaluate the robustness of the proposed method, six different benchmark mathematical functions, and two engineering design problem was performed for optimization to assess its efficiency in achieving optimal solutions to various problems. The results show that the proposed algorithm may well explore better performance than some well-known algorithms in various aspects such as consistency through runs and a fast and steep convergence in all problems towards the global optimal fitness value.
Key Words
championship; GA; meta-heuristic; optimization algorithm; PSO; soccer league
Address
Mohammad R. Ghasemi, Mehdi Ghasri and Abdolhamid Salarnia: Department of Civil Engineering, University of Sistan and Baluchestan, Zahedan, Iran
Abstract
Museum buildings display artefacts for public education and enjoyment, ensuring their long-term safety and the comfort of visitors by following strict indoor environment control protocols using mechanical Heating, Ventilation and Air Conditioning (HVAC) systems to keep the (environmental) variables at a fixed comfort level. Maintaining this requires constant supply of energy currently mostly sourced from the combustion of fossil fuels which exacerbates climate change. However, a review on the effects of the indoor environmental variables on museum artefacts as well as museum visitors revealed that there is no specific point at which artefact deterioration occurs, and that there are wide ranges of conditions that guarantee the long-term safety of artefacts and human comfort. Visits to museum buildings in hot-humid tropical climate of Nigeria revealed that strict indoor environmental practices were adopted. Even when appropriate micro-climatic conditions are provided for artefacts, mechanical HVAC systems remain necessary for visitor comfort because almost no consideration is given to natural ventilation. With the current global push towards energy management, this paper reviewed passive environmental control practices, architectural design strategies, and discusses the adaptation of double skin façade with jali screens, and the notion of smart materials, which can satisfy the range of requirements for the long-term safety of artefacts and levels of human comfort in buildings in hot-humid tropical climate, without mechanical HVAC systems. This review would inspire more discussions on passive, energy efficient, smart and climate responsible popular architecture, challenging current thinking on the impact of the more accepted representative architecture.
Key Words
double skin façade; energy efficiency; indoor environment; mechanical HVAC; museum buildings; passive design; smart materials
Address
Ikechukwu Ogwu, Zhilin Long and Xuhui Zhang: College of Civil Engineering and Mechanics, Xiangtan University, 411105, Hunan, China
Moses M. Okonkwo: Faculty of Environmental Sciences, Nnamdi Azikiwe University, 420110, Awka, Nigeria
Deuckhang Lee and Wei Zhang: Department of Architectural Engineering, Chungbuk National University, 28644, Chungbuk, Republic of Korea
Abstract
Infectious disease emergency hospitals are usually temporarily built during the pneumonia epidemic with higher requirements regarding diagnosis and treatment efficiency, hygiene and safety, and infection control. This study aims to identify how the Building Information Modeling (BIM) + Industrialized Building System (IBS) approach could rapidly deliver an infectious disease hospital and develop site epidemic spreading algorithms. Coronavirus-19 pneumonia construction site spreading algorithm model mind map and block diagram of the construction site epidemic spreading algorithm model were developed. BIM+IBS approach could maximize the repetition of reinforced components and reduce the number of particular components. Huoshenshan Hospital adopted IBS and BIM in the construction, which reduced the workload of on-site operations and avoided later rectification. BIM+IBS integrated information on building materials, building planning, building participants, and construction machinery, and realized construction visualization control and parametric design. The delivery of Huoshenshan Hospital was during the most critical period of the Coronavirus-19 pneumonia epidemic. The development of a construction site epidemic spreading algorithm provided theoretical and numerical support for prevention. The agent-based analysis on hospital evacuation observed "arched" congestion formed at the evacuation exit, indicating behavioral blindness caused by fear in emergencies.
Key Words
BIM+IBS; COVID-19 special hospital; epidemic spreading algorithms; huoshenshan hospital; rapid construction delivery
Address
Chen Wang, Liangcheng Yu and Ziming Wang : College of Civil Engineering, Huaqiao University, 361021, Xiamen, China
Mukhtar A. Kassem: Department of Quantity Surveying, Faculty of Built Environment & Surveying, Universiti Teknologi Malaysia, Skudai 81310, Malaysia
Heng Li: Department of Building and Real Estate, The Hong Kong Polytechnic University, Hong Kong
Abstract
This paper presents a three-dimensional flexible pavement simulated in ANSYS subjected to moving vehicular load on the surface of the pavement typical for the road section in Nepal. The adopted finite element (FE) model of pavement is validated with the classical theoretical formulations for half-space pavement. The validated model is further utilized to understand the damping and dynamic response of the pavement. Transient analysis of the developed FE model is done to understand the time varying response of the pavement under a moving vehicle. The material properties of pavement considered in the analysis is taken from typical road section used in Nepal. The response quantities of pavement with nonlinear viscoelastic asphalt layer are found significantly higher compared to the elastic pavement counterpart. The structural responses of the pavement decrease with increase in the vehicle speed due to less contact time between the tires of the vehicle and the road pavement.
Key Words
flexible pavement, moving vehicular load; three-dimensional analysis; transient analysis; viscoelastic material
Address
Bijay Ban, Jagat K. Shrestha, Rojee Pradhananga and Kshitij C. Shrestha: Department of Civil Engineering, Pulchowk Campus, Institute of Engineering, Tribhuvan University, Lalitpur, Nepal
