McCann Construction Enterprises Inc 11/7/2018

I ' 1 depth of the cut shall be a minimum of 3/4 inch, but shall be reduced if 2 necessary to avoid damaging any reinforcement. For repairs on I 3 vertical surfaces, the top edge shall slope up toward the front at a 1- 4 vertical-to-3-horizontal slope. 5 I 6 7 3. Remove concrete within the repair area to a depth at least matching the cut depth at the edges. Large variations in the depth of removal 8 within short distances shall be avoided. Roughen the concrete surface. I9 The concrete surface should be roughened to at least Concrete 10 Surface Profile (CSP) 5 in accordance with ICRI Guideline No. 310.2R, 11 unless a different CSP is recommended by the patching material 12 manufacturer. ' 13 14 4. Inspect the concrete repair surface for delaminations, debonding, 15 microcracking and voids using hammer tapping or a chain drag. I 16 Remove any additional loose or unsound concrete in accordance with 17 steps 1 through 3. 18 ' 19 5. Select a patching material in accordance with Section 9-20.2 that is 20 appropriate for the repair location and thickness. The concrete 21 patching material shall be pumpable or self-consolidating as required I 22 for the type of placement that suits the repair. The patching material 23 shall have a minimum compressive strength at least equal to the 24 specified compressive strength of the concrete. 25 I26 6. Prepare the concrete surface and reinforcing steel in accordance with 27 the patching material manufacturer's recommendations.At a minimum, 28 clean the concrete surfaces (including perimeter edges) and I 29 reinforcing steel using oil-free abrasive blasting or high-pressure 30 (minimum 5,000 psi) water blasting. All dirt, dust, loose particles, rust, 31 laitance, oil, film, microcracked/bruised concrete or foreign material of I 32 any sort shall be removed. Damage to the epoxy coating on steel 33 reinforcing bars shall be repaired in accordance with Section 6- 34 02.3(24)H. I 35 36 7. Construct forms if necessary, such as for patching vertical or overhead 37 surfaces or where patching extends to the edge or corner of a I 38 placement. 39 40 8. When recommended by the patching material manufacturer, saturate 41 the concrete in the repair area and remove any free water at the I42 concrete surface to obtain a saturated surface dry (SSD) substrate. 43 When recommended by the patching material manufacturer, apply a 44 primer, scrub coat or bonding agent to the existing surfaces. Epoxy I 45 bonding agents, if used, shall be Type II or Type V in accordance with 46 Section 9-26.1. 47 I 48 49 9. Place and consolidate the patching material in accordance with the manufacturer's recommendations. Work the material firmly into all 50 surfaces of the repair area with sufficient pressure to achieve proper I 51 bond to the concrete. I