An Experimental Study on the Joints in Ultra High Performance Precast Concrete Segmental Bridges

2011 ◽  
Vol 23 (2) ◽  
pp. 235-244 ◽  
Author(s):  
Chang-Hong Lee ◽  
Won-Jong Chin ◽  
Eun-Suk Choi ◽  
Young-Jin Kim
Keyword(s):  
Experimental Study ◽  
High Performance ◽  
Precast Concrete ◽  
Segmental Bridges

Performance of Precast Concrete Moment Frames Subjected to Column Removal: Part 1, Experimental Study

PCI Journal ◽  
2017 ◽  
Vol 62 (5) ◽  
Author(s):  
H. S. Lew ◽  
Joseph A. Main ◽  
Yihai Bao ◽  
Fahim Sadek ◽  
Vincent P. Chiarito ◽  
...  
Keyword(s):  
Experimental Study ◽  
Precast Concrete ◽  
Moment Frames ◽  
Column Removal

scholarly journals Influence of Rapid Heat Treatment on the Shrinkage and Strength of High-Performance Concrete

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4102
Author(s):  
Jan Stindt ◽  
Patrick Forman ◽  
Peter Mark
Keyword(s):  
Heat Treatment ◽  
High Performance ◽  
High Performance Concrete ◽  
Treatment Time ◽  
Precast Concrete ◽  
Concrete Strength ◽  
Shrinkage Strain ◽  
Temperature Treatment ◽  
Production Flow ◽  
Steel Fibres

Resource-efficient precast concrete elements can be produced using high-performance concrete (HPC). A heat treatment accelerates hardening and thus enables early stripping. To minimise damages to the concrete structure, treatment time and temperature are regulated. This leads to temperature treatment times of more than 24 h, what seems too long for quick serial production (flow production) of HPC. To overcome this shortcoming and to accelerate production speed, the heat treatment is started here immediately after concreting. This in turn influences the shrinkage behaviour and the concrete strength. Therefore, shrinkage is investigated on prisms made from HPC with and without steel fibres, as well as on short beams with reinforcement ratios of 1.8% and 3.1%. Furthermore, the flexural and compressive strengths of the prisms are measured directly after heating and later on after 28 d. The specimens are heat-treated between 1 and 24 h at 80 °C and a relative humidity of 60%. Specimens without heating serve for reference. The results show that the shrinkage strain is pronouncedly reduced with increasing temperature duration and rebar ratio. Moreover, the compressive and flexural strength decrease with decreasing temperature duration, whereby the loss of strength can be compensated by adding steel fibres.

Investigation of Grouted Coupler Connection Details for Accelerated Bridge Construction

2021 ◽  
pp. 036119812199939
Author(s):  
Brent Phares ◽  
Yoon-Si Lee ◽  
Travis K. Hosteng ◽  
Jim Nelson
Keyword(s):  
Crack Width ◽  
High Performance ◽  
Static Load ◽  
High Performance Concrete ◽  
Precast Concrete ◽  
Chloride Penetration ◽  
Load Testing ◽  
Test And Evaluation ◽  
Load Tests ◽  
Precast Elements

This paper presents a laboratory investigation on the performance of grouted rebar couplers with the connection details similar to those utilized on the precast concrete elements of the Keg Creek Bridge on US 6 in Iowa. The testing program consisted of a series of static load tests, a fatigue test, and evaluation of the chloride penetration resistance of laboratory specimens. The goal of this testing was to evaluate the ability of the grouted rebar couplers to develop flexural capacity at the joint between the precast elements as well as the durability of the connection. For structural load testing, seven full-scale specimens, each with #14 epoxy-coated rebars spliced by epoxy-coated grouted couplers, were fabricated and tested in three different loading cases: four-point bending, axial tension plus bending, and a cyclic test of the system in bending. The static load testing demonstrated that the applied axial load had a minimal effect on the formation of cracks and overall performance of the connection. When ultra-high performance concrete was used as a bedding grout, the initiation of crack was slightly delayed but no considerable improvement was observed in the magnitude of the crack width during loading or the crack closure on unloading. The results of the seventh specimen, tested in fatigue to 1 million cycles, showed little global displacement and crack width throughout the test, neither of which expanded measurably. No evidence of moisture or chloride penetration was detected at the grouted joint during the 6-month monitoring.

Protocolo do experimento - CPBL/MA/FGAD (Projeto: Elaborar seminário de Biodiversidade) v2

2021 ◽  
Author(s):  
Geiser Chalco Challco
Keyword(s):  
Experimental Study ◽  
Collaborative Learning ◽  
High Performance ◽  
Group Formation ◽  
Agile Methods ◽  
Quasi Experimental ◽  
Learning Projects

Main protocol in portugues used to conduct a quasi-experimental study of group formation of high performance in Collaborative-Learning-Projects with Agile Methods

scholarly journals Experimental study of reinforced concrete pile caps with external, embedded and partially embedded socket with smooth interface

2013 ◽  
Vol 6 (5) ◽  
pp. 737-750
Author(s):  
R. Barros ◽  
J.S. Giongo
Keyword(s):  
Experimental Study ◽  
Reinforced Concrete ◽  
Ultimate Load ◽  
Reference Model ◽  
Precast Concrete ◽  
Smooth Interface ◽  
Pile Cap ◽  
Pile Caps ◽  
Monolithic Connections ◽  
Scaled Models

On Precast concrete structures the column foundation connections can occur through the socket foundation, which can be embedded, partially embedded or external, with socket walls over the pile caps. This paper presents an experimental study about two pile caps reinforced concrete with external, partially embedded and embedded socket submitted to central load, using 1:2 scaled models. In the analyzed models, the smooth interface between the socket walls and column was considered. The results are compared to a reference model that presents monolithic connections between the column and pile cap. It is observed that the ultimate load of pile cap with external sockets has the same magnitude as the reference pile cap, but the ultimate load of models with partially embedded and embedded socket present less magnitude than the reference model.

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