Assessment of Dynamic Response of 3D Ultra High Performance Concrete Frame Structure under High Explosion Using Johnson-Holmquist 2 Model

2020 ◽  
Author(s):  
Viet-Chinh Mai ◽  
Ngoc-Quang Vu
Keyword(s):  
Dynamic Response ◽  
High Performance ◽  
High Performance Concrete ◽  
Frame Structure ◽  
Ultra High Performance Concrete ◽  
Concrete Frame

scholarly journals Investigate the Structural Response of Ultra High Performance Concrete Column under the High Explosion

2021 ◽  
Vol 71 (2) ◽  
pp. 256-264
Author(s):  
Viet-Chinh Mai ◽  
Xuan-Bach Luu ◽  
Cong-Binh Dao ◽  
Dinh-Viet Le
Keyword(s):  
Cross Section ◽  
High Performance ◽  
High Performance Concrete ◽  
Blast Resistance ◽  
Load Capacity ◽  
Structural Response ◽  
Blast Loading ◽  
Frame Structure ◽  
Ultra High Performance Concrete ◽  
Main Concept

Most of the structures that are damaged by an explosion are not initially designed to resist this kind of load. In the overall structure of any building, columns play an important role to prevent the collapse of frame structure under blast impact. Hence, the main concept in the blast resistance design of the structure is to improve the blast load capacity of the column. In this study, dynamic analysis and numerical model of Ultra High Performance Concrete (UHPC) column under high explosive load, is presented. Based on the Johnson Holmquist 2 damage model and the subroutine in the ABAQUS platform, a total of twenty UHPC model of the column were calculated. The objective of the article is to investigate the structural response of the UHPC column and locate the most vulnerable scenarios to propose necessary recommendations for the UHPC column in the blast loading resistance design. The input parameters, including the effect of various shapes of cross-section, scaled distance, steel reinforcement ratio, and cross-section area, are analyzed to clarify the dynamic behavior of the UHPC column subjected to blast loading. Details of the numerical data, and the discussion on the important obtained results, are also provided in this paper.

scholarly journals Embedded carbon fiber-reinforced polymer rod in reinforced concrete frame and ultra-high-performance concrete frame joints

2019 ◽  
Vol 11 (S1) ◽  
pp. 35-51
Author(s):  
Shahnaz Basim ◽  
Farzad Hejazi ◽  
Raizal Saifulnaz Bin Muhammad Rashid
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fiber ◽  
High Performance ◽  
High Performance Concrete ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Ultra High Performance Concrete ◽  
Concrete Frame ◽  
Reinforced Polymer

AbstractBeam–column joints play an important role in providing lateral stiffness and integrity of frames during dynamic loading such as earthquake. In the high humidity areas, during functioning of the building cracks occur, which leads to the corrosion of the reinforcement due to the environmental exposures. Therefore, one of the main failures mechanism of building during an earthquake is caused by easily yielding of corroded steel reinforcement, which leads to reduce functionality of the frame joints in transferring the loads. This study proposed a new design to reinforce the beam-column joints with embedded carbon fiber-reinforced polymer (CFRP) rods, due to their extremely high strength and stiffness, along with the fact that they will not rust or corrode and very light weight. CFRP rods are used in reinforced concrete (RC) frame and ultra-high-performance concrete (UHPC) frame subjected to dynamic load. The prototype of the proposed design is constructed as frame with conventional concrete and frame with UHPC material to conduct experiments Test as well as numerical analysis to evaluate the performance of the proposed joints under dynamic loads. The results showed improvement in the performance of the frames reinforced with embedded CFRP in joints in terms of lateral load resistance capacity, ductility behaviour, overall stiffness, and failure mechanism.

Flexural design of precast, prestressed ultra-high-performance concrete members

PCI Journal ◽  
2020 ◽  
Vol 65 (6) ◽  
pp. 35-61
Author(s):  
Chungwook Sim ◽  
Maher Tadros ◽  
David Gee ◽  
Micheal Asaad
Keyword(s):  
Prestressed Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
Limit State ◽  
Design Guidelines ◽  
Design Tool ◽  
Supplementary Cementitious Materials ◽  
Ultra High Performance Concrete ◽  
Concrete Members ◽  
Cylinder Strength

Ultra-high-performance concrete (UHPC) is a special concrete mixture with outstanding mechanical and durability characteristics. It is a mixture of portland cement, supplementary cementitious materials, sand, and high-strength, high-aspect-ratio microfibers. In this paper, the authors propose flexural design guidelines for precast, prestressed concrete members made with concrete mixtures developed by precasters to meet minimum specific characteristics qualifying it to be called PCI-UHPC. Minimum specified cylinder strength is 10 ksi (69 MPa) at prestress release and 18 ksi (124 MPa) at the time the member is placed in service, typically 28 days. Minimum flexural cracking and tensile strengths of 1.5 and 2 ksi (10 and 14 MPa), respectively, according to ASTM C1609 testing specifications are required. In addition, strain-hardening and ductility requirements are specified. Tensile properties are shown to be more important for structural optimization than cylinder strength. Both building and bridge products are considered because the paper is focused on capacity rather than demand. Both service limit state and strength limit state are covered. When the contribution of fibers to capacity should be included and when they may be ignored is shown. It is further shown that the traditional equivalent rectangular stress block in compression can still be used to produce satisfactory results in prestressed concrete members. A spreadsheet workbook is offered online as a design tool. It is valid for multilayers of concrete of different strengths, rows of reinforcing bars of different grades, and prestressing strands. It produces moment-curvature diagrams and flexural capacity at ultimate strain. A fully worked-out example of a 250 ft (76.2 m) span decked I-beam of optimized shape is given.

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