Accession Number PB2012-111528
Title Influence of Differential Deflection on Staged Construction on Deck-Level Connections.
Publication Date 2012
Media Count 91p
Personal Author N/A
Abstract Many rapid construction methods have been investigated and implemented using modular bridge deck components; however, the loadings a bridge might experience during staged construction could force a concentration of differential deflections within the connection and thus reduce the connections service capacity, ultimate capacity, and durability. The research presented herein focused on the effects of differential deflections across a connection on the bond strength between reinforcing bars and field-cast connections in bridge deck-level connections. Six inch cube pull-out type specimens with number four bars were cast. Differential deflections were imparted from casting until final set that ranged from 0.1 in. (0.254 cm) to 0.005 in. (0.0127 cm) of linear bar movement perpendicular to the bar axis. A range of different grout materials which might be deployed in these field-cast connections were engaged in this research program, including standard conventional grouts, deck concretes, ultra-high performance concretes (UHPC), epoxy grout, magnesium phosphate grout, and cable grout. The results of this research provide an initial assessment of whether differential deflections across field-cast connections may be of concern. From the perspective of the pure bond strength, deflecting the rebar prior to final set of the embedment material can have a detrimental effect on the bond. When the rebar deflected 0.05 in. (1.27 mm) or more, reduced bond capacity was observed. When the rebar deflected 0.01 in. (0.25 mm) or less, the results indicate only minor variations in bond strength. This report corresponds to the TechBrief titled Influence of Differential Deflection on Staged Construction Deck-Level Connections (FHWA-HRT-12-055).
Keywords Bonding strength
Bridge decks
Connectors
Construction
Deflection
Grouts
Joints
Precast concrete
Reinforcing bars
Research project

 
Source Agency Federal Highway Administration
NTIS Subject Category 50A - Highway Engineering
50C - Construction Equipment, Materials, & Supplies
Corporate Author Federal Highway Administration, McLean, VA. Office of Research, Development, and Technology.
Document Type Technical report
Title Note N/A
NTIS Issue Number 1226
Contract Number N/A

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