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Page 9 <br /> <br />slab should be considered. The subgrade soils for the exterior slabs should be properly re- <br />compacted. <br /> <br />Slab Subgrade Pre-Saturation <br /> <br />The conventional pre-saturation of subgrade soils to minimum 140% of the optimum <br />moisture content to minimum 24 inches deep is not considered necessary for this project. <br />However, spraying with water should be performed prior to concrete pour. <br /> <br />Other Recommendations for Reducing Slab Cracking <br /> <br />While not a geotechnical issue, the potential for slab cracking may also be reduced by <br />careful control of water/cement ratio and slump of concrete. The contractor should take <br />appropriate curing precautions during the pouring of concrete in hot weather to reduce <br />cracking of slabs. <br /> <br />A slip sheet (or equivalent) can be utilized if grouted tile, marble tile, or other crack- <br />sensitive floor covering is planned directly on concrete slabs. <br /> <br />New Driveway <br /> <br />The minimum section required by the City can be used for a new driveway, if any. If <br />there is no minimum requirements by the City, a 5-inch thick concrete slab (PCC), <br />reinforced with #4 rebar (placed at mid-height of slabs) at 18 inches on-centers both <br />ways, or 5-in. thick asphalt concrete (AC), or equivalent, over a 6-inch thick layer of <br />aggregate base (AB) can be used. The aggregate base and subgrade should be properly <br />compacted to a minimum of 95% and 90%, respectively, of the maximum density <br />determined in accordance with ASTM D1557 prior to placement of the concrete slab. <br />Spraying the compacted subgrade soils with water should be performed prior to concrete <br />pour. <br /> <br />If pavers are to be used, they must be properly designed by the civil engineer of record <br />for this project and approved by the city prior to construction. Additional geotechnical <br />data can be provided for design, if requested. <br /> <br />Site Drainage <br /> <br />In general, proper surface drainage should be checked, improved as needed, and <br />maintained to ensure surface water flows away from all structures. Requirements by the <br />city and applicable CBC (2022 CBC) should also be followed. <br /> <br />Roof gutters should be properly provided. Roof drains, gutters and downspouts should be <br />maintained to function as intended. Outlet drains should be kept open. <br /> <br />Irrigation at the site, if any, should be kept to a minimum required to support plant life. <br />