RICHARD BRADY & ASSOCIATES, INC-A-2020-064

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Oct.1968 CONCRETE RESERVOIR DESIGN 1189 -Dave been built with the joints spaced at about 40 ft or more, the author's experience indicates that a spacing of 20-30 ft provides greater insurance against cracks developing between ;joints. Where unreinforced concrete linings are used, the concrete should be placed in strips 10-12 ft wide and with transverse dummy or weakened plane joints spaced about 10-12 it apart. In many designs, it is desirable to carry the reinforcing steel through the construction joints, such as flat -slab 1-ft 6. Stainless 84.44n. Conlin. Slelnless Steel PI.\ the sealant groove with the bond - breaker. For all horizontal joints in walls, or between footings and walls, the sur- face of the first pour should be sand- blasted, and just before concrete plac- ing is commenced, the space between the forms should be cleaned. The joint surface should be wetted and a sand -cement grout placed on the sur- face of the joint to a depth of J--1-in. The grout should have a water -cement ratio corresponding to that of the concrete being used. Condo. Neoprene Strip Cemented to Concrete } -In. Flat -Head Countersunk Stainless Steel schine Screws @ 24-1n. C.C. In Expan. Shields Conlin. 12-in.x24-tn.xl-in, Rubber Pad l•6, :�" ;:0• �•:,.8 7-in. Stainless Steel Cap Screws Vulcanized to 12.Irr.x24-In.x1G-i% .e .,,. ® 1244. O.C. in Expan. Shields Gage Stainless Steel PI, (One •';� :•.�'; , "! Opposite Each Beam Normal to Join ' ; e-in. Stainless Steel Cap Screws In B-In. Beam Beam expam shields (4 per Pad) rig. 9. Expansion Soint for Concrete Roof That Does Not Serve as a Tension Member roofs as illustrated in Fig. 10, even though this practice increases the tendency toward cracking between the joints. Where the structural design permits, this tendency can be reduced by carrying only half the reinforcing steel across the joints. Cracking be- tween joints can be reduced by placing the concrete in alternate panels and al- lowing them to cure for about 1 week before placing adjacent panels. Wherever vertical joints are to be sealed with waterstops or joint seal- ant, or a combination of the two, the joint face of the first pour should be coated with a suitable bond -breaker. Care should be used to avoid coating Rubber or plastic waterstops should be used in all vertical wall joints as illustrated in Fig, 11. The more com- mon widths of waterstop are 6 and 9 in. Rubber waterstops have been largely replaced with plastic water - stops because joints in plastic are quickly and easily made with a hot knife, whereas rubber requires slow and costly vulcanizing. Joints in rub- ber using a lapped joint bonded with an adhesive have been used at rea- sonable cost, but the life of such joints is dependent upon the life of the ad- hesive, which may be uncertain. In joints where more than a minute amount of movement is anticipated, it RICHARD BRADY &ASSOCIATES, INC. F-58