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<br />346 PORTLAND CEMENT CONCRETE. <br />(REV 1-29-10) (FA 2-1-10) (7-10) <br /> <br />SUBARTICLE 346-3.1 (Pages 320 - 321) is deleted and the following substituted: <br /> <br />346-3.1 General: The separate classifications of concrete covered by this Section are <br />designated as Class I, Class II, Class III, Class IV, Class V and Class VI. Strength, slump, and air <br />content of each class are specified in Table 2. <br />Substitution of a higher class concrete in lieu of a lower class concrete may be <br />allowed, if approved by the Engineer. When the compressive strength acceptance data is less <br />than the minimum compressive strength of the higher design mix, notify the Engineer. <br />Acceptance is based on the requirements in Table 2 for the lower class concrete. <br /> <br /> TABLE 2 <br />Class of Specified Minimum Strength Target Slump Value Air Content <br />Concrete (28-day) (psi) (inches) (c) Range (%) <br /> STRUCTURAL CONCRETE <br />I (a) 3,000 3 (b) 1.0 to 6.0 <br />[ (Pavement) 3,000 2 1.0 to 6.0 <br />II (a) 3,400 3 (b) 1.0 to 6.0 <br />II (Bridge 4,500 3 (b) 1.0 to 6.0 <br />Deck) <br />III (e) 5,000 3 (b) 1.0 to 6.0 <br />III (Seal) 3,000 8 1.0 to 6.0 <br />IV 5,500 3 (b) (d) 1.0 to 6.0 <br />IV (Drilled 4,000 8.5 0.0 to 6.0 <br />Shaft) <br />V (Special) 6,000 3 (b) (d) 1.0 to 5.0 <br />V 6,500 3 (b)(d) 1.0 to 5.0 <br />VI 8,500 3 (b)(d) 1.0 to 5.0 <br /> <br />(a) For precast three sided culverts, box culverts, endwalls, inlets, <br />manholes and junction boxes, the target slump value and air content will not apply. The <br />maximum allowable slump is6 inches, except as noted in (b). The Contractor is permitted to use <br />concrete meeting the requirements of ASTM C 478 4,000 psi in lieu of Class I or Class II <br />concrete for precast endwalls, inlets, manholes and junction boxes. <br />(b) The Engineer may allow a higher target slump when a Type F, G, lor <br />II admixture is used, except when flowing concrete is used. The maximum target slump shall be <br />7 inches. <br />(c) For a reduction in the target slump for slip-form operations, submit a <br />revision to the mix design to the Engineer. <br />(d) When the use of silica fume, ultrafine fly ash, or metakaolin is required <br />as a pozzolan in Class IV, Class V, Class V (Special) or Class VI concrete, ensure that the <br />