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<br />03300 - 14/22 <br />unit, and clearance of the drum, shall be checked before a further attempt to <br />use the unit will be permitted. <br />3. The use of non-agitating equipment for transporting ready-mixed concrete will <br />not be permitted. The quality and quantity of materials used in ready-mixed <br />concrete and in batch aggregates shall be subject to continuous inspection at <br />the batching plant by the ENGINEER. <br />4. Each batch of concrete shall be mixed in a truck mixer for not less than 70 <br />revolutions of the drum or blades at the rate of rotation designated by the <br />manufacturer of equipment. Additional mixing, if any, shall be at the speed <br />designated by the manufacturer of the equipment as agitating speed. All <br />materials including mixing water shall be in the mixer drum before actuating the <br />revolution counter for determining the number of revolution of mixing. <br />3.05 PLACING: <br />A. Non-Conforming Work or Materials: Concrete which during or before placing is <br />found not to conform to the requirements indicated herein shall be rejected and <br />immediately removed from the WORK. Concrete which is not placed in accordance <br />with these Specifications, or which is of inferior quality, shall be removed and <br />replaced. <br />B. Unauthorized Placement: No concrete shall be placed except in the presence of a <br />duly authorized representative of the ENGINEER. The CONTRACTOR shall notify <br />the ENGINEER in writing at least 24 hours in advance of placement of any concrete. <br />C. Concrete shall not be dropped more than four feet (4’) without use of chutes or <br />tremies. Concreting shall be a continuous operation until placement of the section is <br />complete. All concrete shall be worked around reinforcement and embedded items. <br />If vibrators are used, care shall be taken not to segregate concrete. Vibrators will not <br />be allowed to move concrete within the form. All forms and subgrade shall be <br />dampened prior to placement and excess water removed. <br />D. Placing of concrete shall conform to the applicable requirements of Chapter 8 of ACI <br />301 and the requirements of this Section. <br />E. Placement in Slabs: Concrete placed in sloping slabs shall proceed uniformly from <br />the bottom of the slab to the top, for the full width of the placement. As the work <br />progresses, the concrete shall be vibrated and carefully worked around the slab <br />reinforcement, and the surface of the slab shall be screeded in an up-slope direction. <br />F. Concrete shall not be dropped through reinforcement steel or into any deep form, nor <br />shall concrete be placed in any form in such a manner as to leave accumulation of <br />mortar on the form surfaces above the placed concrete. In such cases, means such <br />as hoppers and, if necessary, vertical ducts of canvas, rubber, or metal shall be used <br />for placing concrete in the forms in a manner that it may reach the place of final <br />deposit without separation. Concrete shall be uniformly distributed during the <br />process of depositing and in no case after depositing shall any portion be displaced <br />in the forms more than 6-feet in horizontal direction. Concrete in wall forms shall be <br />deposited in uniform horizontal layers not deeper than 2-feet; and care shall be taken <br />to avoid inclined layers or inclined construction joints except where such are required <br />for sloping members. Each layer shall be placed while the previous layer is still soft. <br />The rate of placing concrete in wall forms shall not exceed 5-feet of vertical rise per <br />hour. Sufficient illumination shall be provided in the interior of all forms so that the <br />concrete at the places of deposit is visible from the deck or runway.