Figure 7-12. - Repair of deck at center of span.

Figure 7-13. - Repair to damaged edge of slab.

in figure 7-14; or in addition to beveling, the area to be removed may first be scored along the break line, using a saw, to a depth of 1 1/2 inches. The depth is to be adjusted where reinforcing is encountered. No joint in the slab should be made either adjacent to or at the edge of a supporting beam or at or near the ends of reinforcing bars. If the slab must be cut back to the supporting beams or replaced, a seat should be cut into the beam to the depth of the slab and one quarter to one third of the width of the beam. If deck slabs have been damaged by heaving (lateral or upward movement resulting from freeze/thaw cycles), they must be replaced. Make provisions for an adequate expansion joint in the new slab. If two or more adjacent slabs have heaved, you will often find that piles have been pulled up with the slabs. When this condition occurs, the piles should be re-driven to a

Figure 7-14. - Heaving of concrete deck.

firm bearing and necessary repairs made to concrete caps. (See fig. 7-15.)

If EXPANSION JOINTS have proven inadequate in number or are not functioning properly, heaving will result. Where joints are too far apart, cut additional joints with a concrete saw and fill them with an approved type of joint sealer. Asphalt, tar, and certain other materials may be used with satisfactory results for sealing joints. Sealing material should adhere to the concrete and should remain plastic at all temperatures. It should not become hard and brittle in low temperatures or so soft that it flows from-the joint during intense heat or so tacky that it is picked up by vehicle tires.

RESURFACING concrete pier decks that have widespread surface deterioration may be restored by resurfacing with asphalt. The existing slab must be properly prepared before placement of the new asphalt surface course. Clean all loose, scaled, and foreign matter down to sound concrete, using power wire brooms and compressed air. Flush with high-pressure fresh water to remove salt if near seawater. All cracks must be cut to a clean rectangular trench, usually not less than 1/2 inch wide by 1 1/2 inches deep (adjust depth to suit reinforcing steel). Fill the trench to within one-half inch of the top with a high-softening point asphalt mastic or joint-filling compound. Paint the surface of the concrete for 3 to 4 inches on both sides of the trench with asphalt emulsion and cover with 30-pound asphalt-impregnated felt 4 inches wider than the trench. It is very important to seal the cracks