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A. Remove concrete to the depths shown or required. Roughen contact surfaces by chipping, sandblasting, scarifying or other approved methods. Thoroughly dean the surface removing loose particles and dust. B. Cut off projecting reinforcement when required to provide at least I inch cover. Where shown, reinforcement shall be bent across cut face and covered with new concrete. C. Thoroughly wash the roughened concrete surfaces and keep the surfaces saturated for at least 6 hours before placing new concrete. All free water shall be removed prior to placing the concrete. An epoxy bonding compound as specified may be used in lieu of saturating surface for 6 hours. D. Cement mortar, where required, shall be placed to a thickness slightly in excess of the finished surface and shall be steel-trowel-finished, flush with the adjacent surface. E. When the finish surface is not specified to be coated the color of new concrete in the exposed surfaces shall match the color of the existing adjoining concrete as closely as possible. F. Cement mortar shall consist of 1 part portland cement and two parts of sand by volume. No accelerating admixtures shall be employed in surface treatment. Where shown on the Drawings, a non-shrink grout, shall be used for patching and filling. 3.04 CONNECTIONS, NEW CONCRETE TO EXISTING CONCRETE A. The Contractor shall drill 1 1/2 inch holes for dowels. The drilled hole shall first be filled with epoxy bonding compound, then dowels shall be inserted by tapping. These holes shall be blown clear of loose particles and dust prior to installing epoxy bonding compound. Where shown on the Drawings, expansion bolts shall be installed in place of bonded dowels. B. Unless otherwise noted on the Drawings, No. 5 dowels set 12 inches into the concrete, and projecting 12 inches, 24 inches on center shall be used. C. Where it is necessary to expose existing reinforcement, the reinforcing rods shall be cleaned by wire brushing and new reinforcement shall be hooked into existing reinforcement and lapped or welded as directed. Reinforcing rods shall have at least 3/4 inch clearance around each bar. D. All mixing and application of the epoxy shall be done,in strict accordance with the printed instructions of the approved manufacturer. The Contractor shall submit to the Engineer, when requested, evidence indicating that the proposed applicators are fully qualified to perform the work and any proposed applicator found to be not qualified shall, be removed forthwith by the Contractor. E. Preparation of Concrete Surfaces: 1. Surfaces must be clean and sound. Surfaces may be dry, damp, or wet, but free of standing water. Remove dust, laitance, grease, curing compounds, 08/12 03700-3 11-4179