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DocuSign Envelope ID:AOF53191-262C-4CB2-B674-9AB9C758A904 <br /> C. Limit water-soluble,chloride-ion content in hardened concrete to 0.30 percent by weight of cement. <br /> D. Admixtures:Use admixtures according to manufacturer's written instructions. <br /> 1. Use water-reducing,high-range water-reducing or plasticizing admixture in concrete,as required, <br /> for placement and workability. <br /> 2. Use water-reducing and retarding admixture when required by high temperatures,low humidity,or <br /> other adverse placement conditions. <br /> 3. Use water-reducing admixture in pumped concrete and concrete with a water-cementitious <br /> materials ratio below 0.50. <br /> 2.11 CONCRETE MIXTURES FOR BUILDING ELEMENTS <br /> A. Footings:Proportion normal-weight concrete mixture as follows: <br /> 1. Minimum Compressive Strength: 6000 psi at 28 days. <br /> 2. Maximum Water-Cementitious Materials Ratio: 0.50. <br /> 3. Slump Limit:4 inches,plus or minus 1 inch. <br /> 4. Air Content: 5.5 percent,plus or minus 1.5 percent at point of delivery for 1-1/2-inch nominal <br /> maximum aggregate size. <br /> B. Slabs-on-Grade: Proportion normal-weight concrete mixture as follows: <br /> 1. Minimum Compressive Strength: 6000 psi at 28 days. <br /> 2. Minimum Cementitious Materials Content:470 lb/cu.yd. <br /> 3. Slump Limit:4 inches,plus or minus 1 inch. <br /> 4. Air Content:Do not allow air content of trowel-finished floors to exceed 3 percent. <br /> 2.12 FABRICATING REINFORCEMENT <br /> A. Fabricate steel reinforcement according to CRSI's"Manual of Standard Practice." <br /> 2.13 CONCRETE MIXING <br /> A. Ready-Mixed Concrete:Measure,batch,mix,and deliver concrete according to ASTM C 94/C 94M,and <br /> furnish batch ticket information. <br /> 1. When air temperature is between 85 and 90 deg F,reduce mixing and delivery time from 1-1/2 <br /> hours to 75 minutes;when air temperature is above 90 deg F,reduce mixing and delivery time to <br /> 60 minutes. <br /> PART 3 -EXECUTION <br /> 3.1 FORMWORK <br /> A. Design,erect,shore,brace,and maintain formwork,according to ACI 301,to support vertical,lateral, <br /> static,and dynamic loads,and construction loads that might be applied,until structure can support such <br /> loads. <br /> B. Construct formwork so concrete members and structures are of size, shape,alignment,elevation,and <br /> position indicated,within tolerance limits of ACI 117. <br /> C. Limit concrete surface irregularities,designated by ACI 347 as abrupt or gradual,as follows: <br /> 1. Class B, 1/4 inch for rough-formed finished non-exposed surfaces. <br />