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Mr. Gerald A. Newton <br />December 18, 1995 <br />Page 2 <br /> <br />Task: <br />Estimated Cost: <br />Expected Result: <br /> <br />Sealing of hairline cracks in Principal Spillway; <br />$12,000.00 <br />Hairline cracks (<0.05") in the Principal Spillway wilt be <br />cleaned and sealed by topcoating in such manner to <br />completely fill the cracks to prevent the intrusion of <br />water/moisture into the structure. <br /> <br />Task: <br /> <br />Estimated Cost: <br />Expected Result: <br /> <br />Sealing of construction joints in Principal Spillway as <br />directed by NC Dam Safety Office; <br />$17,500.00 <br />Construction Joints in the Principal Spillway will be cleaned, <br />and sealed such that an elastomeric bond will be obtained on <br />both sides of the joint between the caulk and the structure. <br />This will prevent the intrusion of water/ moisture into the <br />structure. <br /> <br />It is our recommendation that Items I through 3 be accomplished as soon as possible utilizing the <br />methods outlined in Underwater Unlimited Diving Service's proposal of March 3, 1995. This <br />information has been reviewed and approved by NC Dam Safety. <br /> <br />Item 4 has not been specifically reviewed with NC Dam Safety. We have discussed with UUDSI <br />coating the affected areas with a topcoat sealant. We concur in UUDSI's recommendation to use <br />Sika's Pronto 19 for coating the concrete surfaces of affected portions of the top row of concrete slabs <br />on the Principal Spillway. At an estimated coverage at approximately 100 SF per gallon, and an area <br />to be treated of approximately 4,000 SF, the estimated cost is $12,000.00. <br /> <br />For Item 5, as has been previously discussed, UUDSI's first proposal for sealing the construction joints <br />required sawcutting of all joints with an opening less than 0.25-inches. As noted after a field review of <br />the joints conducted in May 1995, this may require the sawcutting of 80 to 90 % of the approximately <br />1,200 LF of construction joints in the spillway (see attached Photo Log dated May 16, 1995, revised <br />December 5, 1995). For economic and other considerations, neither we nor NC Dam Safety (see <br />attached letter dated November 30, 1995) favor this amount of sawcutting. Based on the estimated <br />lengths of joints as listed in the Photo Log, we recommend the following approach to sealing the <br />construction joints: <br /> <br />Joint Width (in.) Len~h Repair <br /> <br />0.2 - 0.25 All <br />0.05 - 0.15 All <br /><0.05 All <br /> <br />Sikaflex TR Caulk (without sawcutting) <br />Sikaflex TR Caulk (with sawcutting) <br />Topcoat Sealant <br /> <br /> <br />