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<br />519 3.1.3 Section 206 -Excavation and Backfill for Structures <br />520 206.01 Description. This work consists of the excavation, and backfill or disposal of all <br />521 material required for the construction of structures. The excavation and disposal of excavated <br />522 material for ditches and channels shall be accomplished in accordance with (Section 203. <br />523 <br />524 All excavation and backfill for structures below the designed slope or sub@;rade line provided in <br />525 the Contract shalt be included under this item. Unless otherwise specified„ structure excavation <br />526 shall include all pumping, bailing, draining, sheeting, bracing, and incidentals required for proper <br />527 execution of the work. <br />528 <br />529 Materials <br />530 <br />531 <br />532 <br />533 <br />534 <br />535 <br />536 <br />537 <br />538 <br />539 <br />540 <br />541 <br />206.02 General. All structure backfill, bed course material, and filter material will be accepted <br />in place. <br />(a) Structure Bac~ll. Class 1 and Class 2 structure backfill shall be composed of non-organic <br />mineral aggregates and soil from excavations, borrow pits, or other sources. Material shall <br />conform to the requirements of subsection 703.08. Class of material shall be as specified in <br />the Contract or as designated. <br />Structure backfill (flow-fill) meeting the following requirements shall be used to backfill <br />bridge abutments. The Contractor may substitute structure backfll (tlow-fill) for structure <br />backfill (class 1) or structure backfill (class 2) to backfill culverts and sewer pipes. <br />Ingredients <br />Cement <br />Coarse Aggregate <br />(AASHTO No. 57 or 67) <br />Fine Aggregate (AASHTO M 6) <br />Water <br />542 <br />543 <br />544 <br />545 <br />546 <br />547 <br />548 <br />549 <br />550 <br />Lbs./Cu.Yd. <br />50 <br />1700 <br />1845 <br />325 (or as needed} <br />The amount of water shall be such that the structure backfill (flow-fill) flows into place <br />properly without excessive segregation. Approximately 39 gallons of water per cubic yard of <br />structure backfill (flow-fill) is normally needed. <br />The Contractor may use aggregate which does not meet the above specifications if the <br />cement is increased to 100 pounds per cubic yazd and the aggregate conforms to the <br />following gradation: <br />Sieve Size _ _ Percent Passing <br />25.0 mm (1 inch) ~ 100 <br />75 m (No. 200)_ 0-10 <br />551 <br />552 <br />553 <br />The Contractor may substitute 30 pounds per cubic yard of cement and 30 pounds per cubic <br />yard of fly ash for 50 pounds per cubic yard of cement or may substitute 60 pounds per cubic <br />3-14 <br />G \101~0p100.OT4\Reports\IW~Terhni~at $pBCI(IW~1One Coc February 3, X006 <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />lJ <br /> <br />r <br /> <br /> <br /> <br /> <br /> <br />