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<br />03300 - 21/22 <br />1. Patch all tie holes, honeycombs or other defects with a Portland Cement and <br />sand grout. <br />2. Defective surfaces to be repaired shall be cut back from trueline a minimum <br />depth of 1/2-inch over the entire area. Feathered edges will not be permitted. <br />Where chipping or cutting tools are not required in order to deepen the area <br />properly, the surface shall be prepared for bonding by the removal of all <br />laitance or soft material, plus not less than 1/32-inch depth of the surface film <br />from all hard portions by means of an efficient sandblast. <br />3. After cutting and sandblasting, the surface shall be wetted sufficiently in <br />advance of shooting with shotcrete or with cement mortar so that while the <br />repair material is being applied, the surfaces underneath will remain moist but <br />not so wet as to overcome the suction upon which a good bond depends. <br />4. Holes left by tie-rod cones shall be reamed with suitable toothed reamers so as <br />to leave the surfaces of the holes clean and rough. Holes then shall be <br />repaired in an approved manner with dry-packed cement grout. Holes left by <br />form-tying devices having a rectangular cross-section and other imperfections <br />having a depth greater than their least surface dimension shall not be reamed <br />but shall be repaired in an approved manner with dry-packed cement grout. <br />5. The grout shall not be richer than one (1) part cement and three (3) parts sand <br />with the amount of mixing water enough to produce a workable mix. For <br />exposed walls, the cement shall contain such a proportion of white portland <br />cement as is required to make the color of the patch match the color of the <br />surrounding concrete. The patch shall be finished in such a manner as to <br />match the adjoining surfaces. <br />6. Surfaces of repairs shall receive the same kind and amount of curing treatment <br />as required for the concrete in the repaired section. <br />B. Defective Concrete: <br />1. Any concrete which is not formed as shown on the Drawings or does not <br />conform to the Contract tolerances or shows defects which reduce its structural <br />adequacy, shall be removed from the job by the CONTRACTOR at his <br />expense unless the Engineer grants permission to patch the defective area. <br />C. Exposed Concrete Surfaces: <br />1. As soon as forms are removed, exposed surfaces shall be carefully examined <br />and all ridges, ribs and other imperfections shall be rubbed with an abrasive <br />stone or ground in a satisfactory manner in order to secure a smooth, uniform <br />and continuous surface. Plastering or coating of surfaces to be smoothed will <br />not be permitted <br />2. No repairs shall be made until after inspection by the ENGINEER. <br />3. In no case will extensive patching of honeycombed concrete be permitted <br />4. Concrete containing minor voids, pinholes, honeycombing, or similar <br />depression defects shall be repaired as indicated below. <br />5. Concrete containing extensive voids, holes, honeycombing, or similar <br />depression defects shall be completely removed and replaced. Repairs and <br />replacements shall be performed promptly.