SNiP 2.05.03-84*

СНиП на английском языке SNiP 2.05.03-84*

3.128. Bends of longitudinal tensional bars by contour of reentrant angles resultant from breakage of element surface are not allowed. Bars of longitudinal reinforcement situated along planes making angle of break shall be extended behind point of their crossing with the length of at least 20 reinforcement diameters.

Anchoring of pretensioned reinforcement

3.129*. When using for structures pretensioned reinforcement of ribbed bars of up to 36mm diameter anchors for rods are not required.

For elements of reinforcement designed for impact all reinforcement (except for specified above) shall have inner and outer (end) anchors.

For pretensioned elements with reinforcement not designed for impact some cables of K-7 class and high-tensile ribbed wires may be used without anchors (inner and outer).

Anchoring strength applied for posttensioned structures shall not be less than strength of anchored reinforcement elements.

3.130. For flexural elements reinforcement anchors shall not be placed in concrete zones with main tensile and compression strength above 90% of maximum values specified for such stress.

3.131*. Outer (end) anchors of beam end face shall be placed as uniform as possible. In doing so solid steel plates covering anchors concrete zone shall be provided at the ends. Plates edges shall be anchored in concrete.

Thickness of covering plates shall be calculated and determined depending on tension forces of prestressing tendons and shall be as follows:

at least 10 mm – for tension force of 590 kN (60 tension force);

at least 20 mm – for tension force of 1180 kN (120 tension force);

at least 40 mm – for tension force of 2750 kN (280 tension force).

For forces different from the specified above thickness of covering plates shall correspond to the nearest value.

3.132. For posttensioned elements concrete zone of outer anchors shall be armored by cross-cut meshes with ribbed rods of at least 10mm diameter and cells up to 10×10 cm. Distance between the meshes shall be up to 10 cm.

Longitudinal reinforcement of elements

3.133*.  In welded reinforcement cages the reinforcements shall be situated in groups up to three rods in each. Rods in groups shall be interconnected by single welding bonding joints. Length of bonding joints between rods shall be at least 4 diameters and its thickness – up to 4 mm. Gaps between groups shall be made by means of longitudinal clips of at least 25 mm diameter. The clips shall be set behind bends with distance between each other of up to 2.5 m in a staggered order. They shall be welded to main reinforcement by single bonding joints of up to 4 mm thickness and length of at least 2 diameters of main reinforcement.

Welding bonding joints between grouped rods shall be done in a staggered order in relation to clips and adjacent bonding joints with clear distance between them of at least 40 cm in case the adjacent joints are on single longitudinal rod and 10 cm if bonding joints are done for different longitudinal rod of the cage. In addition it is required that any cross section of group of rods crosses only one welding joint.

If it is rational vertical rods of welded meshes in walls may be resistance spot welded to reinforcement and longitudinal clips situated between groups of rods. Electrical arc welding of collar clamps to main reinforcement is not allowed.

It is recommended to use reinforcement of As-II class 10 GT grade for cages of main reinforcement.

Details on joints for main reinforcement are specified in item 3.160*.