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DIVISION 03 Section 3450 - Architectural Precast Concrete-Plant Cast , <br /> F. Other Dimensional Tolerances: Numerically the greater of plus or minus 1/16 inch , <br /> (1.6 mm)per 10 feet(3 m),or plus or minus 1/S inch(3.2 mm). <br /> 2.13 FINISHES <br /> A. Finish exposed-face surfaces or azchitectural precast concrete units as follows to � <br /> match Architect's design reference sample. <br /> 1. Smooth-surface finish free of pockets,sand streaks,and honeycombs,with , <br /> uniform color and texiure. <br /> 2. Textured-surface finish imparted by form liners or inserts to provide surfaces free � <br /> of pockets,streaks,and honeycombs,with uniform color and texture. <br /> 3. Finish exposed back surfaces of azchitectural precast concrete units by smooth, � <br /> steel-trowel 6nished. <br /> 2.14 SOURCE QUALIT'Y CONTROL ' <br /> A. The Owner may employ an independent testing agency to evaluate architectural <br /> Precast concrete fabricator's quality control and testing methods. ' <br /> 1. Allow Owner's test�ng agency access to material storage areas,concrete production <br /> equipment, concrete placement,and curing faciliiies.Cooperate with ' <br /> Owner's testing agency and provide saznples of materials and concrete mixes as <br /> may be requested for additional testing and evaluation. <br /> B. Quality-Control Testing:Test and inspect architectural precast concrete according , <br /> to MIL-117 requirements. <br /> C. Strength of architectural precast concrete units will be considered deficient when , <br /> they fail to comply with ACI 318(ACI 318M)requirements. <br /> D. Testing:When there is evidence that the strength of azchitectural precast concrete ' <br /> units may be deficient or may not meet ACI 318(ACI 318M)requirements,the Owner <br /> will employ an independent testing agency to obtain,prepare,and test cores drilled <br /> from hazdened concrete to determine compressive strength according to ASSTM C 42. , <br /> 1. A minimum of 3 representative cores will be taken from architectural precast concrete <br /> units of suspect strength, from locations directed by Architect. <br /> 2. Cores will be tested in an air-dry condition. ' <br /> 3. Strength of concrete for each series of 3 cores will be considered satisfactory if the <br /> average compressive strength is equal to at least 85 percent of the 28-day design <br /> compressive strength and no single core is less than 75 percent of the 28-day design <br /> compressive strength. ' <br /> 4. Test results will be made in writing on the same day that tests aze made,with copes to <br /> Architect,Contractor,and precast fabricator.Test reports will include the Project � <br /> identification nazne and number,date,name of precast concrete fabricator,name of concrete <br /> testing agency;identification letter,name,and type of architectural precast concrete unit or <br /> units represented by core tests;design compressive strength,compressive strengEh at break <br /> and type of break,corrected for length-diameter ratio,and direction of applied load to core , <br /> with respect to horizontal plane of concrete as placed. <br /> , <br /> 03450- 8 <br /> HENNEPIN COUNTY Orono Salt Stora¢e <br /> Marcb 22,2002 Project No.:0031569 Contract No.:0751R2 � <br />