Development of Multi-Tee-Type Precast Concrete Slabs with Insulating Materials for Structural Safety at the Construction Stage

Multi-tee-type precast concrete (PC) slab systems are widely used for the construction of modular high-load long-span buildings. However, the structural safety of the dapped end is uncertain, owing to the unanchored shear reinforcement at the construction stage. This study proposes the use of clip-type shear reinforcement at the dapped ends of multi-tee PC slabs to secure their structural performance at the construction stage. To investigate the performance of this approach, a monotonic loading test was performed on simply supported PC slabs, considering structural safety at the construction stage. The reinforcement details of the PC slab’s dapped end (with existing Z-type or proposed clip-type shear reinforcement) and the shear-to-span ratio (12.8 or 6.4) were considered as test parameters. The load–deflection relationship, failure mode, strength ratios to the predicted strength, and shear reinforcement strains were analyzed. The results showed that the tested flexural strength ratio of the PC slabs at the construction stage to the design flexural strength was 1.20–1.40. The enclosed shape and diagonal arrangement of the clip-type shear reinforcement enabled sufficient anchorage performance at the dapped end, indicating that clip-type shear reinforcement can be viable for use at the dapped ends of PC slabs under construction loads.

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Research of a New Form Traveler on Cable-Stayed Bridge

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.333-335.2119 ◽

2013 ◽

Vol 333-335 ◽

pp. 2119-2122

Author(s):

Xiao Lei ◽

Yong Jun Zhou ◽

Yu Feng Liu ◽

Yu Zhou ◽

Jian Min Wang

Keyword(s):

Southeast Asia ◽

Bearing Capacity ◽

Main Beam ◽

Loading Test ◽

Construction Stage ◽

Cable Stayed Bridge ◽

New Form ◽

Under Construction

The second Penang Bridge is a new bridge under construction in Penang, and will become the longest bridge in Malaysia and Southeast Asia. The purpose of this test is to estimate the bearing capacity of the form travelers in the second Penang Bridge. The pre-loading test simulates the construction stage of the typical edge beam and slab section. By observing the strain and deformation data of the form travelers, stress and displacement were analyzed to ascertain the performance and safety of form travelers and to provide evidence for the main beam alignment control in construction.

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The risk assessment and management of a long span cable stayed bridge under construction stage

Bridge Maintenance, Safety, Management and Life Extension ◽

10.1201/b17063-418 ◽

2014 ◽

pp. 2803-2809

Author(s):

Y Yang ◽

R Ma ◽

A Chen

Keyword(s):

Risk Assessment ◽

Construction Stage ◽

Cable Stayed Bridge ◽

Long Span ◽

Under Construction ◽

Risk Assessment And Management

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Stress monitoring of long-span steel truss during construction stage in Hangzhou International Expo Center

MATEC Web of Conferences ◽

10.1051/matecconf/202031909001 ◽

2020 ◽

Vol 319 ◽

pp. 09001

Author(s):

Jindi Lin ◽

Yongbin Wei ◽

Maowei Qiao

Keyword(s):

Monitoring System ◽

Health Monitoring ◽

Steel Structure ◽

Steel Structures ◽

Structural Safety ◽

Stress Monitoring ◽

Construction Stage ◽

Monitoring Scheme ◽

Large Span ◽

Long Span

According to the requirement of building function, the large-span steel structures are constantly appearing in recent years. It is necessary to establish a set of feasible methods for health monitoring of long-span steel structures. This paper introduces the structural health monitoring of large-span steel structure in Construction Stage, including the method of Structural simulation, the wireless monitoring system of large-span steel structure, the installation method of sensors, the judgment method of structural safety and the maintenance of monitoring system. Taking Hangzhou International Expo Center as an example, all construction steps of the main large-span steel structure were simulated by the finite element analysis software. Through the structure of simulation calculation, the key members of the structure were found out, and the monitoring scheme was determined and carried out. In order to get the accurate stress data during the implementation of the monitoring scheme, this paper introduced some attentive details of sensor installation. The limitation of the key steel elements was obtained according to the related norms, and it provided the judgment for the safe of structure. After the smooth construction of the project, we could find that the stress monitoring system meted the monitoring requirement during the construction stage, and the results were an important evaluation index for the structure. The research methods used in this paper could be seen as useful reference for construction of similar projects. Stress monitoring of long-span steel struss during construction stage in Hangzhou International Expo Center.

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Impact of Reinforcement Ratio on Shear Behavior of I-Shaped UHPC Beams with and without Fiber Shear Reinforcement

Materials ◽

10.3390/ma13071525 ◽

2020 ◽

Vol 13 (7) ◽

pp. 1525 ◽

Cited By ~ 1

Author(s):

Altug Yavas ◽

Cumali Ogun Goker

Keyword(s):

Shear Strength ◽

Failure Mode ◽

High Performance Concrete ◽

Shear Behavior ◽

Reinforcement Ratio ◽

Steel Fibers ◽

Experimental Program ◽

Shear Reinforcement ◽

Ultimate Shear Strength ◽

Loading Test

In the presented paper, the impacts of steel fiber use and tensile reinforcement ratio on shear behavior of Ultra-High Performance Concrete (UHPC) beams were investigated from the point of different tensile reinforcement ratios. In the scope of the experimental program, a total of eight beams consisting of four reinforcement ratios representing low to high ratios ranged from 0.8% to 2.2% were casted without shear reinforcement and subjected to the four-point loading test. While half of the test beams included 30 mm end-hooked steel fibers (SF-UHPC) with 2.0 vol%, the remaining beams were produced without the fiber to show possible effectiveness of the fiber use. The shear performances were discussed in terms of the load—deflection response, cracking pattern and failure mode, first cracking load and ultimate shear strength. In this sense, all the non-fiber beams were failed by shear with a dramatic load drop, regardless of the tensile reinforcement amount, before the yielding of reinforcement and they produced no deflection capability. The test results showed that while the inclusion of steel fibers to the UHPC mixture with low reinforcement ratios changed the failure mode from the shear to flexure, it significantly enhanced the ultimate shear strength in the case of higher reinforcement ratio through the SF-UHPC’ superior mechanical properties and fibers’ crack-bridging ability.

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One Vanderbilt: Unprecedented Project Delivery Through Integrated Innovation

IABSE Congress, New York, New York 2019: The Evolving Metropolis ◽

10.2749/newyork.2019.1851 ◽

2019 ◽

Author(s):

Andrew Cleary ◽

Edward M. DePaola ◽

Christopher R. Horch

Keyword(s):

New York ◽

Structural Steel ◽

Fast Track ◽

Urban Environments ◽

Advanced Technology ◽

Parametric Modelling ◽

Under Construction ◽

Construction Loads ◽

Design Schedule ◽

Construction Documents

One Vanderbilt Avenue, currently under construction in midtown Manhattan, will be one of the tallest buildings in New York. By collaborating with the construction teams in the early stages of the design, the foundations and the superstructure were able to proceed well in advance of a typical project. For example, the structural steel was erected to the 6th floor, was fabricated to the 32nd Floor, and the shop drawings were checked up to the 45th floor on the day that the 100% Construction Documents were issued.The structural steel frame was designed so that its core columns only carried 12 levels of framing and construction loads during the tower’s erection. A concrete shear wall system followed the steel framing, permitting the steel erection to proceed without regard to the concrete operations. When complete, the project will stand 1,401 feet tall and contain 26,000 tons of structural steel, and 93,000 cubic yards of concrete.The presentation focuses on the challenges and technological requirements for vertical construction in dense urban environments. It explains the amount of detail, thought, and knowledge of construction that must happen earlier in the design process and the participants will appreciate how the fast‐track process can be applied to complex architectural, mechanical and structural designs.It describes the integration of design team parametric modelling with the construction process early in the design schedule. Fast‐track projects with complex designs like One Vanderbilt can be successfully completed by understanding and integrating an IPD process, even with competing objectives. The presentation discusses the challenges and technological requirements for vertical construction in dense urban environments, including the importance of direct links to mass transportation.This type of team structure is the future of the industry, and One Vanderbilt is the first of its kind to illustrate how innovative design ambitions are being realized through the use of increasingly refined and advanced technology.

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Experimental Study of a New Precast Prestressed Concrete Joint

Applied Sciences ◽

10.3390/app8101871 ◽

2018 ◽

Vol 8 (10) ◽

pp. 1871 ◽

Cited By ~ 2

Author(s):

Xueyuan Yan ◽

Suguo Wang ◽

Canling Huang ◽

Ai Qi ◽

Chao Hong

Keyword(s):

Energy Dissipation ◽

Seismic Performance ◽

Prestressed Concrete ◽

Precast Concrete ◽

Concrete Strength ◽

Frame Structure ◽

Loading Test ◽

Concrete Frame ◽

Concrete Joints ◽

Precast Prestressed Concrete

Precast monolithic structures are increasingly applied in construction. Such a structure has a performance somewhere between that of a pure precast structure and that of a cast-in-place structure. A precast concrete frame structure is one of the most common prefabricated structural systems. The post-pouring joint is important for controlling the seismic performance of the entire precast monolithic frame structure. This paper investigated the joints of a precast prestressed concrete frame structure. A reversed cyclic loading test was carried out on two precast prestressed concrete beam–column joints that were fabricated with two different concrete strengths in the keyway area. This testing was also performed on a cast-in-place reinforced concrete joint for comparison. The phenomena such as joint crack development, yielding, and ultimate damage were observed, and the seismic performance of the proposed precast prestressed concrete joint was determined. The results showed that the precast prestressed concrete joint and the cast-in-place joint had a similar failure mode. The stiffness, bearing capacity, ductility, and energy dissipation were comparable. The hysteresis curves were full and showed that the joints had good energy dissipation. The presence of prestressing tendons limited the development of cracks in the precast beams. The concrete strength of the keyway area had little effect on the seismic performance of the precast prestressed concrete joints. The precast prestressed concrete joints had a seismic performance that was comparable to the equivalent monolithic system.

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