The full-depth cuts provide no load transfer capacity and can begin to pump or punch into the subbase, causing unnecessary damage. Sawing operations should not precede removal and repair operations by more than two days. This distance may be reduced depending on the required lap length. The recommended distance is 610 mm (24inches) for tied laps, and 200 mm (8 inches) for mechanical connections or welded laps. The distance depends on the method of lapping used to connect reinforcement. Partial-depth and full-depth sawcuts for CRCPĪfter the partial-depth cuts, two full-depth sawcuts are then made at a specified distance in from partial-depth cuts. They should not cross an existing crack, and adequate room should be left for the required lap distance and center area.įigure 9. The partial depth cut should be located at least 460 mm (18 inches) from the nearest tight transverse crack. If any of the steel reinforcement is sawed through, the length of the patch must be increased by the lap length required (Figure 8 and 9). The outer boundaries of repair should be cut, partial-depth above the steel reinforcement, with a diamond blade saw. The contractor may elect to use one or more wheel saw cuts within each patch area to give removal equipment space to grasp the old concrete. One way to cure this problem is to saw at night during cooler temperatures, or provide pressure-relief cuts with carbide-toothed wheel saws. If diamond-bladed saws bind during hot weather, then the concrete slabs are in compression from thermal expansion. This is to ensure that the base of the blade reaches the intersection with the transverse boundary cuts. To avoid spalling damage during removal, the sawing operation should be continued through the joint. Any interior or centerline longitudinal joint also requires a full-depth cut through the existing joint reservoir. Diamond-bladed saws produce straight, smooth, vertical faces that improve the accuracy of dowel bar placement. It is preferable to use diamond-bladed saws for full-depth transverse cuts. The full-depth cuts separate the segment of deteriorated concrete and allows room for its removal with minimal damage to surrounding materials. Full-depth Sawing transverse boundariesīefore removing deteriorated concrete, isolate the area from adjacent concrete and shoulder materials using full-depth saw cuts. However, if the distressed areas in both lanes are similar and both lanes are to be repaired, aligning repair boundaries to avoid small offsets and to maintain continuity may be desirable. The patch is not tied to the adjacent lane.A separation fiberboard has been placed along the longitudinal joint.All of the deteriorated area has been included within the repair boundaries.The minimum length requirements are met.On multiple-lane highways, it is generally not necessary to match joints in adjacent lanes, as long as: It may be more economical to place additional doweled transverse joints at 4.6m interval than to place reinforcement. Reinforcement is needed in JRCP where the patch length is longer than 4.6m (15 ft).If distress is present on only one side of an existing nondoweled joint, that joint may be used as a boundary.A boundary that would fall at an existing doweled transverse joint should be extended 0.3 m (1 ft) to include the existing joint.The minimum recommended distance from the full-depth repair joints to the nearest transverse crack or joint is 1.8m (6 ft).The recommended minimum repair length is 1.8m (6 ft) for repairs provided with mechanical load-transfer devices, and 2.4 - 3m (8 -10 ft) for repairs with aggregate interlock joints. Guidelines for locating repair boundaries are provided below: Partial-depth repairs are only appropriate for spalls within the top one-third of the slab. If the project plans contain partial-depth repairs, the project specifications should include a special provision that provides the engineer freedom to change some partial-depth repair to full-depth repairs. Additional areas of distress that have occurred since the initial survey should be included. Each distressed area should be examined and the repair boundaries marked on the slab surface. This survey should be conducted as close to the contract schedule as possible. Repair boundaries can be determined by making a field survey utilizing data from initial project survey. The construction and installation of full-depth repairs involve the following steps: Full-Depth Repairs 5.0 Construction Procedure
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