CONTRACTION JOINT Russian patent published in 2007 - IPC E01D19/06 

FIELD: construction, particularly to erect cast-in-place building structures, namely bridge and tunnel roadway pavings and other elongated structures, without control joints.

SUBSTANCE: contraction joint comprises partition extending for the full reinforced concrete member cross-section length and transversal reinforcement. Longitudinal reinforcement is made as continuous bars in member cross-section near the joint. Partition is made as sheet transversal to longitudinal reinforcement direction and provided with anchors connected to one sheet side. Contraction joint also has additional reinforcement anchors fastened in pairs to all continuous bars of longitudinal reinforcement so that each additional anchor is located from each side of the partition and spaced 1a distance from it. The distance 1a is determined from condition of comparability of total continuous reinforcement bar resiliency value determined in above area with resiliency of reinforced concrete member having L length. Cross-sectional area F_r of all continuous reinforcement bars is determined from condition of compatibility of separate longitudinal reinforcement tensile strength and total reinforced concrete member tensile strength, wherein reinforced concrete member cross-sectional area is equal to f_b. Summary area F_r of continuous longitudinal reinforcement bars and length l_a of the area is determined from corresponding relations.

EFFECT: increased reliability and service life of elongated monolithic building structures erected without control joints.

2 cl, 8 dwg