(A) Classification. The following classifications of concrete shall govern and apply:
(1) Four thousand pound sand-gravel and limestone (27% to 33%) for foundations that extend above grade exposed to weather; all structural concrete columns, beams, spandrels, walls and slabs, exterior sidewalks, curbing, miscellaneous exterior concrete. Minimum of 6 bags of cement per cubic yard, maximum of 5-1/2 gallons of water per bag of cement.
(2) Five hundred pound sand-gravel and limestone (27% to 33%) for high strength columns and all precast concrete units other than exposed aggregate units. Minimum of 7 bags of cement per cubic yard. Maximum of 4-1/2 gallons of water per bag.
(3) Seven thousand pound sand-gravel and coarse aggregate (50% to 60%) for 1-inch topping for industrial building floors subject to considerable wear or slight chemical attack. Minimum of 9 bags of cement per cubic yard. Maximum of 4 gallons of water per bag.
(4) Four thousand pound sand-gravel for troweled floors of grade not subject to severe wear or any chemical attack. Also for 1-1/2 or thicker topping material not subject to severe wear or any chemical attack. Minimum of 6-1/2 bags of cement per cubic yard. Maximum of 5-1/2 gallons of water per bag.
(5) Three thousand pound sand-gravel for footings, foundations below grade and base coarse for slabs on grade to receive topping. Minimums of 5-1/2 bags of cement per cubic yard. Maximum of 6-1/2 gallons of water per bag.
(B) Mixing, pouring, forms and reinforcement.
(1) All materials used in making concrete shall be mixed until they have been uniformly distributed.
(2) Mixtures shall be poured continuously, and shall not be poured in freezing weather unless proper precautions are taken.
(3) Double forms shall be used for all foundation walls of basements. Metal reinforcement of concrete shall conform to the requirements of the A.S.T.M.
(1) Garage, basement, terrace and porch floors and walks which are inside property lines, when made of concrete, shall be of not less than 4 inches in thickness and shall be placed on a compacted bed. Concrete driveways shall be of not less than 4 inches in thickness.
(2) Concrete slab floors placed directly on earth shall be not less than 4 inches thick. Topping when poured monolithic with the slab may be included as a structural part of the slab. Sleepers for the nailing of a wood floor shall not decrease the required structural depth of the slab unless placed in the direction of span and then shall not be placed more than ½ inch into the slab.
(3) Concrete slab floors directly on earth shall be not less than 4 inches thick. The slabs shall be designed structurally to support all live and dead loads as outlined in this subchapter.
(Prior Code, § 12-161) (Ord. 3035, § 1, 9-5-1995)
