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9. Trenc backfill within the public way shall be compacted to a minimum of 95% Relative <br /> Maxi um Density as determined by AASHTO T99, method D as corrected for oversize by <br /> AAS TO T-224. Lifts or layer shall not exceed 24 inches in depth. Compaction shall be <br /> acco plished using mechanical vibrators or impact tampers. Wheel rolling by a truck or <br /> backh e shall not be acceptable. <br /> Withi streets, alleys, and sidewalks trench backfill shall consist of 3/4"-0 Crushed Base <br /> Aggre ate or, with prior approval, controlled density fill. Controlled density fill may be <br /> requir d in trenches less than 15" wide or where the Inspector determines mechanical <br /> comp etion devices are impractical or ineffective. Pea gavel shall not be allowed as an <br /> o do . <br /> Contr lied density fill (CDF) may be used in trenches crossing a street or alley right-of--way <br /> at rig angles to the alignment. With prior consent, the Inspector may allow CDF backfill <br /> parall 1 to the right-of--way. Excavated materials shall not be allowed for use as trench <br /> backf 11 except in unimproved portions of the public way. <br /> Contr lied density fill (CDF), also known as flowable backfill, is a cementious material <br /> mixe ,transported, and delivered using normal ready mixed concrete operations. CDF is a <br /> mixtu e of cement, aggregates, water, and admixtures such as fly ash proportioned to provide <br /> a non segregating, self consolidating, free-flowing, and hand-excavatable material. CDF <br /> is a h rdened, dense, non-settling fill that requires no compaction effort. <br /> Ades gn mix shall be submitted for review and approval prior to use of CDF. The mixture <br /> shall e designed to ensure that the material placed has a 7-day compressive strength of <br /> betty n 50 psi and 150 psi. The compressive strength shall be tested using 4-inch mortar <br /> cubes per ASTM C 109. <br /> Traffi may temporarily be placed directly upon CDF prior to paving as soon as it has <br /> suffic ently hardened so that the surface will withstand traffic or construction equipment <br /> loadi g without deformation. If CDF is used as a temporary surface restoration material, the <br /> surfa e shall be maintained and repaired due to damage by traffic. <br /> 10. All p rtland cement concrete used in the replacement of streets, alleys, or sidewalks shall <br /> obtai a minimum breaking strength of 3,000 psi in 28 days and conform to sections 212 <br /> throu h 215 of the Standard Specifications. <br /> 11. All o namental surfacing shall be replaced "in-kind" to that surfacing removed. <br /> 12. Whe sections of sidewalk are requested to be removed by the permittee, they shall be <br /> remo ed to the nearest existing score or joint in each direction. <br /> 13. Whe sections of curb or curb and gutter are removed by the permittee, a minimum often <br /> Utility & R/ Permit Policy <br /> Exhibit A - 2~ r:\adminord\rules\OOrowrlexa.wpd(09/13/00) <br /> <br /> ~I <br /> <br />