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DIVISION 03 Sec�tion 3450 - Architectural Precast Concrete-Plant Cast � <br /> 2.10 MOLDS � <br /> A. Accurately construct molds,mortar tight,of sufficient strength to withstand pressures due <br /> to concrete-placing operations,temperature changes,and for pretensioning and ' <br /> defiensioning operaiions. <br /> B. Maintain molds to provide completed architectural precast concrete units of shapes,lines, <br /> and dimensions indicated,within fabrication fiolerances specified. � <br /> 2.11 FABRICATION <br /> A. Accurately position cast-in anchors,inserts,plates,angles, and other anchorage hardware S <br /> for attachment of loose hardware and secure in place during precasting operations.Locate <br /> anchorage hardware where it does not affect the position of the main reinforcement or the <br /> placing of concrete. ' <br /> B. Supply loose steel plates,dip angles,seat woes,anchors,dowels,cramps,hangers,and <br /> other hazdware shapes not provided by other trades necessary for securing architectural ' <br /> precast concrebe uniis to supporting and adjacent members. <br /> C. Cast in reglets,slots,holes and other accessories in architecturai precast concrete units fio <br /> receive windows,cramps,dowels,reglets,waterstops,flashings,and other similar work as , <br /> indicated.Coordinabe with other trades for installation of cast in ibems. <br /> D. Reinfarcement Comply with the recommendations of CRSI's"Manual of Standard , <br /> Practice"far fabricating,placing,and supporting reinforcement. <br /> 1. Clean reinforcement of loose rust and mill scate, earth,and other materials that reduce <br /> or destroy the bond with concrete. ' <br /> 2. Accurabely position,support,and secure reinforcement against displacement during <br /> mncrete placement and consolidation operations.Complebely conceal support devices <br /> to prevent exposure on finished surfaces.Do not use plastic-coated or uncoated metal , <br /> chair supports. <br /> 3. Place reinforcement bo maintain the specified minimum cover afber finishing. � <br /> Arrange,space,and securely tie bars and bar supports to hold reinforcement in <br /> posiiion while placing concrete.Direct wire tie ends away from finished,exposed <br /> concrebe surfaces. <br /> 4. Install welded wire fabric in lengths as long as practicable. Lap adjoining pieces at ' <br /> least one full mesh and lace splices with wire.Offset laps of adjoining widths fio <br /> prevent continuous laps in either direction. � <br /> E. Reinforce architectural precast concrete units to resist handling,transportation,and <br /> erection stresses. <br /> F. Pretension tendons for architectural precast,prestressed concrete uniis either by single- t <br /> strand tensioning method or multiple�trand bensioning method.Comply with MNL-117 <br /> requirements. ' <br /> G. Mix concrete according to MNL-117 and requirements of this Section. Following concrete <br /> botching,no additional water may be added. <br /> H. Place face mix fio a aunimum thickness afber consolidation of the greater of 2-inch or 1S � <br /> times the maximum aggregate size,but not less th�n the minimum reinforcement cover. <br /> , <br /> 03450- 6 <br /> HENNEPIN COUNTY Orono Salt Stora�e , <br /> March 22,2002 Project No.:0031569 Contract No.:0751R2 <br />