An Experimental and Analytical Study on the Deflection Behavior of Precast Concrete Beams with Joints

Abstract

The use of precast concrete modular construction in the replacement and rebuilding of old structures has recently increased. However, the joints between modules in this type of construction exhibit special behavior that should be considered when analyzing the behavior of modular members. Both stability and serviceability should be studied; however, existing research has only addressed the former. Research regarding serviceability, involving deflection and crack development and propagation, is lacking. This study considers the difference in strength between on-site cast and precast segmental concrete to accurately evaluate the deflection of precast concrete flexural members with joints within the lapped splice. In addition, to reflect an initial crack, the deflection is calculated and evaluated by reflecting the effect of tension-stiffening and subsequently redefining the attached transmission lengths of the left and right sides of the cracked surface as a new cracked region. As a result of explicitly including joint behavior which is considered attached transmission length and characteristic by concrete strength, a more accurate calculation of deflection is developed.

Keywords

• precast concrete
• joint
• crack
• concrete strength
• deflection
• unit load method
• curvature