Borough of Fanwood, NJ Miscellaneous Concrete Structure Specifications

§ A385-52 General provisions.

Cement, sand, and crushed stone for concrete shall conform to the requirements therefor specified in Article II of this chapter. Unless otherwise specified, the size of crushed stone shall be three-fourths-inch.

Sand and crushed stone shall be kept clean and free from foreign matter until used.

Except where otherwise specifically provided, concrete shall be Class A, B, C, or D, as may be prescribed, proportioned as follows:

Class	Cement	Sand	Crushed stone
A	1	1.50	3.0
B	1	1.75	3.5
C	1	2.00	4.0
D	1	2.25	4.5

The class of concrete required for the various items of work shall be as shown on the plans or in the specifications.

§ A385-53 Reinforcement steel; wire mesh.

Reinforcement steel shall be placed when required by the plans. Bars shall conform to the requirements of Article II of this chapter. Wire mesh shall be of a type and quality approved by the Borough Engineer.

§ A385-54 Equipment.

Batching and mixing equipment must be of a size and type suitable for the work to be done and subject to the approval of the Borough Engineer.

§ A385-55 Batching and mixing.

The contractor shall notify the Borough Engineer not less than three days before he is ready to start preparing concrete. The Borough Engineer will determine the quantities of materials, including water, required for a batch. No subsequent changes shall be made by the contractor in the material quantities, unless such changes are directed by the Borough Engineer.

After all materials, including water, have been placed in the mixer, the materials shall be mixed for a period of not less than 13/4 minutes and as much longer as may be necessary to produce a thorough and uniform mixture of the concrete. The mixer shall be emptied completely after the mixing of each batch. The mixer shall be thoroughly cleaned if not used for a period of 30 minutes.

§ A385-56 Consistency.

The concrete mixer shall contain the least amount of water possible for proper workability. In general, its consistency shall be such that the mortar clings to the stone; that the mixture will not segregate during transportation and handling; that the mixture, when dropped, will flatten but not spread; that there is no appearance of free water; that the mixture in a chute will slide and not flow into place; that the slump is from two to three inches; and that the concrete when set will show a cement film, but is free from laitance.

§ A385-57 Forms.

Forms may be of wood or metal. They shall be constructed to conform to the lines and grades established by the Borough Engineer and to the exact dimensions of the structure. They shall be substantially constructed, strong, rigid, and mortar-tight, and properly braced and tied. The forms shall be designed so that they can be removed without causing damage to the concrete. All forms shall be constructed, braced, and lined up so as to produce smooth concrete surfaces without bulges and warps. Before concrete is placed in the forms, the latter shall be thoroughly cleaned so as to remove all loose and foreign material within them, and they shall be coated with oil approved by the Borough Engineer to prevent discoloration or adherence of concrete.

§ A385-58 Removal of forms.

Forms and their supports shall not be removed until the Borough Engineer has approved such removal.

§ A385-59 Placing of reinforcement steel.

Reinforcement steel shall be accurately placed and fastened in a manner approved by the Borough Engineer. Distances from the forms shall be maintained by means of stays, blocks, ties, hangers, or other approved supports. When placed, the reinforcement steel shall be inspected and approved before the concrete is placed.

Splicing of reinforcement steel, except where shown on the plans or approved by the Borough Engineer, will not be permitted. At splices, the bars shall be rigidly clamped or wired together in a manner acceptable to the Borough Engineer. Sheets of metal mesh shall overlap so as to maintain uniform strength, and shall be securely fastened.

§ A385-60 Placing of concrete.

The placing of the concrete mixture shall be conducted so as to produce a dense, compact, impervious structure of uniform texture and with smooth exposed surfaces. The concrete mixture shall be placed immediately after being mixed, in such a manner that segregation does not occur and the reinforcement steel is not displaced. A concrete mixture not placed within 30 minutes of the time when water was first added to the mixture shall not be used. The concrete mixture shall not be dropped for a distance of more than five feet and shall not be deposited in quantity at one point and subsequently run or worked along the forms. Care shall be taken to fill each part of the forms and to work the crushed stone back from the face. The concrete shall be compacted by continuous working with suitable tools.

Concrete shall not be deposited in running water and, except with the written approval or direction of the Borough Engineer, it shall not be deposited in or exposed to water before setting.

Concrete shall not be placed when the atmospheric temperature is below 36° F., except with the Borough Engineer's approval. When such approval is given, the contractor will be required to heat the concrete aggregate and water so that the concrete mass, when placed in the forms, shall have a temperature of not less than 60° F., and the contractor shall furnish such protection for the fresh concrete as the Borough Engineer may direct.

§ A385-61 Construction joints.

Construction joints shall be placed only where shown on the plans or as directed by the Borough Engineer. When a concrete mixture is to be placed against set concrete, all loose and foreign material shall be removed from the surface of the latter and the surface shall be cleaned with wire brooms and saturated with water.

§ A385-62 Expansion joints.

Expansion joints shall be formed by means of a premoulded joint filler approved by the Borough Engineer, and shall be provided at points shown on the plans or required by the specifications.

§ A385-63 Curing.

The curing shall be done by one of the following methods:

(1)

Surfaces may be cured by coating with a colorless curing compound, meeting the requirements of the 1941 New Jersey State Highway Department Standard Specifications, as amended, applied uniformly by means of an approved spray distributor at the rate of one gallon per 30 square yards of surface or as much more as may be required, in the opinion of the Borough Engineer, to obtain a complete sealing coat. The coating shall be applied before any marked dehydration or surface checking has taken place.

(2)

Horizontal surfaces may be cured by placing thereon a layer of straw or hay, to the thickness directed by the Borough Engineer, which shall be kept wet during the curing period.

The curing material shall be placed on all surfaces not covered with forms or from which the forms have been removed, and shall remain for not less than seven days after the placing of the concrete.

§ A385-64 Defective work.

Defective work shall be replaced or repaired as the Borough Engineer may direct. If the surface of the concrete is bulged or uneven, develops cracks, or shows honeycombing or joint marks which cannot be repaired satisfactorily, in the opinion of the Borough Engineer, the entire section of concrete affected shall be removed and replaced at the contractor's expense.

§ A385-65 Surface finishes.

As soon as the forms have been removed, the concrete surfaces shall be carefully examined, and cavities, irregularities, honeycombing, and other defects which, in the opinion of the Borough Engineer, may not justify rejection of the work shall be pointed with mortar as used for the concrete or shall otherwise be repaired as the Borough Engineer may direct.