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<br />n <br />LJ <br />n <br />L.J <br />" <br />LJ <br />" <br />LJ <br />" <br />U <br />" <br />u <br />n <br />u <br />" <br />LJ <br />n <br />l-J <br />n <br />LJ <br />II <br />L.J <br />II <br />U <br />(' <br />LJ <br />rl <br />L.J <br />r, <br />U <br />n <br />LJ <br />" <br />LJ <br />" <br />LJ <br />06/05 <br />11 <br />L..J <br /> <br />D. When high-early-strength Portland cement is permitted, the same strength requirements <br />shall apply except that the indicated strengths shall be attained at seven (7) days instead of <br />twenty-eight (28) days. <br /> <br />E. If during the progress of the work it is impossible to secure concrete of the required <br />workability and strength with the materials being furnished, the Engineer may order such <br />changes in proportions or materials, or both, as may be necessary to secure the desired <br />properties. All changes so ordered shall be made at the Contractor's expense. <br /> <br />F. If during the progress of the work the Contractor desires to use materials other than those <br />originally approved, or if the materials from the sources originally approved change in <br />characteristics, the Contractor shall, at his own expense, have made new acceptance tests of <br />a~gregates and establishment of new basic mixtures and submit them to the Engineer for <br />approval. <br /> <br />G. Consistency of the concrete as measured by the ASTM DesignationCI43 shall be as <br />shown in (Table B). <br /> <br />TABLE B <br /> <br />Portion of Structure <br /> <br />Slump <br />Max. * <br /> <br />(inches) <br />Min. <br /> <br />Pavement and slabs on ground 3 2 <br />Plain footings, gravity walls, <br />slabs and beams 3 2 <br />Heavy reinforced foundation <br />walls and footings 4 2 <br />Thin reinforced walls and columns 4 2 <br />* May be increased I-inch if proper method of consolidation is used. <br /> <br />H. Concrete shall be of such consistency and mix composition that it can be readily worked <br />into the corners and angles of the forms and around the reinforcement, inserts, and wall <br />castings without permitting materials to segregate or free water to collect on the surface, <br />due consideration being given to the methods of placing and compacting. <br /> <br />I. No excessively wet concrete will be permitted, and if at any time concrete of such <br />consistency beyond the limits of Table B is delivered to the job, the Engineer may direct <br />the Contractor to reject same or to add extra cement for which no additional payment will <br />be made. A supply of the approved cement shall be kept available at the site for this <br />purpose. Drivers of transit-mix trucks shall add no additional water except that established <br />for the design. Failure to comply with this requirement shall be justification for rejecting <br />the concrete. <br /> <br />1. The entrained air, as measured by the Pressure Method, ASTM C231, shall be as shown in <br />(Table C). <br /> <br />TABLE C <br /> <br />Nominal Maximum Size <br />of Coarse Aggregate(jn) <br /> <br />Total Air Measured at <br />Discharge from truck (%) <br /> <br />2" <br />I" <br />3/4" <br /> <br />2.5 - 5.5 <br />6.5 <br />4.0 - 8.0 <br /> <br />03300-3 <br /> <br />03-4138.8 <br />