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40-27 BUILDING CAST -IN -PLACE CONCRETE <br />BRPH ARCHITECTS -ENGINEERS, INC. <br />B. Patching Mortar: Mix dry -pack patching mortar, consisting of one part portland cement <br />to two and one-half parts fine aggregate passing a No. 16 sieve, using only enough <br />water for handling and placing. <br />C. Repairing Formed Surfaces: Surface defects include color and texture irregularities, <br />' cracks, spalls, air bubbles, honeycombs, rock pockets, fins and other projections on <br />the surface, and stains and other discolorations that cannot be removed by cleaning. <br />1. Immediately after form removal, cut out honeycombs, rock pockets, and voids <br />' more than 1 /2 inch in any dimension to solid concrete. Limit cut depth to 3/4 <br />inch. Make edges of cuts perpendicular to concrete surface. Clean, dampen <br />with water, and brush -coat holes and voids with bonding agent. Fill and compact <br />' with patching mortar before bonding agent has dried. Fill form -tie voids with <br />patching mortar or cone plugs secured in place with bonding agent. <br />2. Repair defects on surfaces exposed to view by blending white portland cement <br />' and standard portland cement so that, when dry, patching mortar will match <br />surrounding color. Patch a test area at inconspicuous locations to verify mixture <br />and color match before proceeding with patching. Compact mortar in place and <br />' strike off slightly higher than surrounding surface. <br />3. Repair defects on concealed formed surfaces that affect concrete's durability and <br />structural performance as determined by Engineer. <br />D. Repairing Unformed Surfaces: Test unformed surfaces, such as floors and slabs, for <br />finish and verify surface tolerances specified for each surface. Correct low and high <br />areas. Test surfaces sloped to drain for trueness of slope and smoothness; use a <br />sloped template. <br />1. Repair finished surfaces containing defects. Surface defects include spalls, <br />popouts, honeycombs, rock pockets, crazing and cracks in excess of 0.01 inch <br />wide or that penetrate to reinforcement or completely through unreinforced <br />sections regardless of width, and other objectionable conditions. <br />' 2. After concrete has cured at least 14 days, correct high areas by grinding. <br />3. Correct localized low areas during or immediately after completing surface <br />finishing operations by cutting out low areas and replacing with specified polymer <br />' repair mortar. Finish repaired areas to blend into adjacent concrete. <br />4. Correct other low areas scheduled to receive floor coverings with specified <br />underlayment. Prepare, mix, and apply repair underlayment and primer <br />according to manufacturer's written instructions to produce a smooth, uniform, <br />plane, and level surface. Feather edges to match adjacent floor elevations. <br />5. Correct other low areas scheduled to remain exposed with a repair topping. Cut <br />out low areas to ensure a minimum repair topping depth of 1/4 inch to match <br />' adjacent floor elevations. Prepare, mix, and apply repair topping and primer <br />according to manufacturer's written instructions to produce a smooth, uniform, <br />plane, and level surface. <br />' 6. Repair defective areas, except random cracks and single holes 1 inch or less in <br />diameter, by cutting out and replacing with fresh concrete. Remove defective <br />areas with clean, square cuts and expose steel reinforcement with at least a 3/4- <br />inch clearance all around. Dampen concrete surfaces in contact with patching <br />concrete and apply bonding agent. Mix patching concrete of same materials and <br />mixture as original concrete except without coarse aggregate. Place, compact, <br />and finish to blend with adjacent finished concrete. Cure in same manner as <br />adjacent concrete. <br />C06922.001.00 03 30 04 - 17 <br />05-22-14 <br />