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Home My WebLink AboutPLANSl TECHNICAL GUIDELINES Prepared by the Technical Guidelines Committee of ICRI October 1989 (re -issued March 1995) SG:ANNtl BY St. Lucie Cnl in', _ Guideline No. 03730 _ - - -- - - - - CoMigN ©19951nternational CD=ete Repair IZiVe ■ Exposing and Undercutting of Reinforcing Steel = _ ■ Cleaning and Repair of Reinforcing Steel ■ Edge and Surface Conditioning of Concrete Removal Geometry Caution! Before starting removals, review effect of removals on structural integrity. Provide shoring of v� memberas necessary. Particularcare shall be exercised at slab/beam connections to columns. Section Elevation Elevation Beam or Rib Section ^o o c Column 0 o Comer — - Slab or Wall Partial Depth FILE Cury n o 0 0 �NtppuUHrl� Slab or Wall a - .BRE..... Full Depth '%9�•. FCOR��P 03730-2 'pry, t�'igl, _ ite Repair Institute J, 4�1 OR Exposing and Undercutting of Reinforcing Steel These details are applicable to horizontal, vertical. and overhead locations. They are also applicable to removal by hydro -demolition. hydro -milling, and elec- tric. pneumatic or hydraulic impact breakers. Q Remove loose or delaminated concrete above cor- roded reinforcing steel. Q Once initial removals are made, proceed with the undercutting of all exposed corroded bars. Under- cutting will provide clearance for under bar clean- ing and full bar circumference bonding to surrounding concrete, and will secure the repair structurally. Provide minimum'/: inch (19 mm) clearance between exposed rebars and surrounding concrete or'/: inch (6 mm) larger than largest aggregate in repair material, whichever is greater. Q Concrete removals shall extend along the bars to locations along the bar free of bond inhibiting corrosion, and where the bar is well bonded to surrounding concrete. Q If non -corroded reinforcing steel is exposed dur- ing the undercutting process, care shall be taken not to damage the bar's bond to surrounding concrete. If bond between bar and concrete is broken, undercutting of the bar shall be required. © Any reinforcement which is loose shall be secured in place by tying to other secured bars or by other approved methods. Surface Preparation Guide Ll Cleaning and Repair of Reinforcing Steel Cleaning of Reinforcing Steel Q All heavy corrosion and scale should be removed from the bar as necessary to promote maximum bond of replacement material. Oil free abrasive blast is the preferred method. A tightly bonded light rust build-up on the surface is usually not detrimental to bond- unless a protective coating is being applied to the bar surface, in which case the coating manufacturer's recommendations for sur- face preparation should be followed. Concrete substrate _Reinforang steel Abrativ¢ / — Nozzle Abrasive Paths Cleaning baoksfde of corroded Bars-/ Repair of Reinforcing Steel Due to Loss of Section �� F 1 �- % a g .;�,,, SSIONP�x��xx If reinforcing steel has lost significant cross section, a New bars may be mechanically s tix!iiT1 old bars structural engineer should be consulted. If repairs are orplaced parallel to and approximately-/4in. (19 mm) required to the reinforcing steel, one of the following from existing bars. Lap lengths shall be determined repair methods should be used: in accordance with AC1318: also refer to CRSI and • Complete bar replacement, or AASHTO manual. • Addition of supplemental bar over affected section. Required Lap' Affected Length Loss of Section Supplemental liar Affected Length Required Lap 03730-4 Intemational Concrete Repair Institute J