Excepting where the estimated amount of asphalt paving to be done is less than 100 square yards, each bidder must submit with his bid a letter stating the commercial names (if any) and the proportion, nature and derivation of the refined asphalt and the flux he proposes to use.

Before the award of the contract, the successful bidder shall furnish for testing, samples of all materials to be used in the manufacture of the paving mixture. Should the material submitted be found unsatisfactory, then other samples must be furnished immediately. Failure to comply with this will be deemed cause for forfeiture of bidder's bond or deposit.

Satisfactory evidence if requested must be presented to the Director of Public Service that the bidder has been regularly engaged in the business of laying asphalt pavements or is reasonably familiar therewith and is fully prepared with the necessary capital, materials and machinery to conduct the work to be contracted for to the satisfaction of the Engineer.

General Description. - The subgrade for Asphalt Pavement will be --------inches below and parallel to the finished grade of the roadway. On the subgrade, prepared as specified under "Grading," Item 1 will be deposited--------- inches of concrete as specified, the upper surface of which shall be compact and true, parallel to and 3 inches below the finished roadway grade. If deemed necessary by the Engineer, the surface of the concrete shall be roughened by tamping with toothed rammers or by other satisfactory means.

Upon the foundation thus prepared, shall be laid the pavement proper. This shall consist of:

1. A binder course, 1 1/2 inches in thickness when compressed.

2. An asphalt wearing surface, 1 1/2 inches in thickness when compressed. Samples. - Samples of the refined asphalt, petroleum flux, asphalt cement, sand, filler, and binder stone that the Contractor proposes to use in his work, together with a statement as to the source and character of these materials, shall be submitted to the Engineer at any time that he may so request. No materials other than those specified in his bid shall be used, except with the written consent of the Engineer. Other samples taken from and actually representative of the shipments received shall be submitted to the Engineer at least two weeks before the work begins; also, during the course of the work all shipments of new materials be used without having been examined and approved by the Engineer. The Contractor shall furnish the Engineer or his authorized inspector all facilities for the sampling of materials.

Methods of Testing. - All tests of materials must be conducted according to the official methods on file in the office of the Engineer. The Contractor must provide a suitable room at the plant in which an inspector, appointed by the Engineer, can carry out all chemical and physical tests required to keep the process of manufacture under proper control.

Refined Asphalts. - The refined asphalts admitted under these specifications shall be prepared from any natural mineral bitumen, either solid or liquid, or from combinations thereof, by suitable and approved methods of refining. The preparation and refining of all asphalts shall be subject to such inspection at the paving plants and refineries as the Engineer may direct. Every refined asphalt admitted under these specifications shall be equal in quality to the recognized standard for its particular type or kind of asphalt. All refined asphalts must comply with the following requirements:

(A) All shipments of refined asphalt of any one kind shall be uniform in composition and consistency. The penetration of the material in any shipment shall not vary more than ten points.

(B) Asphalts obtained by the distillation of petroleum oils shall have a penetration of not less than 30 at 70° F.

(C) Ninety-eight and one-half per cent. of the total bitumen of all refined asphalts must be soluble in cold carbon tetrachloride.

(D) When made into an asphalt cement by the use of such materials and methods as described in these specifications, they must produce an asphalt cement complying with all the requirements elsewhere set forth herein for asphalt cements.

If desired, the Contractor may use an asphalt cement prepared at the refinery. To be acceptable, this asphalt cement must comply with the above requirements for refined asphalt, and must also comply with the requirements for asphalt cement as given below.

Fluxes. - Fluxes shall be the residuum obtained by the distillation of paraf-fine, semi - asphaltic, or asphaltic petroleums. They shall be of such character as to combine with the refined asphalt to be used to form an acceptable asphalt cement complying with all the requirements of these specifications. All fluxes must pass the following tests:

(A) They must have a penetration of more than 350° with a No. 2 needle at 77° F. under 50 grams weight for two seconds.

(B) The specific gravity at 60° F. shall be between 0.94 and 1.04.

(C) When 50 grams are heated in a tin box, 2 1/2" in diameter and 1 1/2" in height for 5 hours, at 325° F., they shall lose by volatilization not more than 5% by weight. The residue left after heating shall have a penetration greater than 200.

(D) They shall not flash below 350° F. when tested in a New York State closed oil tester.

(E) They shall be soluble in carbon tetrachloride to the extent of not less than 99 per cent.

Asphalt Cements. - The asphalt cement shall be composed of refined asphalt or asphalts, and flux, where flux is required, of the character specified elsewhere herein. The proper proportions of refined asphalt and flux shall be melted together and thoroughly agitated by suitable appliances until they are combined into a homogeneous asphalt cement. Under no circumstances shall asphalt cement be used which has had insufficient agitation. If the asphalt cement contains materials which will separate by subsidence while it is in a molten condition, means must be provided for constant agitation of the asphalt cement. The asphalt cement must never be heated to a temperature in excess of 350° F. For the purpose of recording temperatures in the asphalt kettles, recording pyrometers shall be provided as specified elsewhere herein. The methods of agitation must be of such a type as to cause no injury to the asphalt cement. The refined asphalt or asphalts and flux shall, when required, be weighed separately, in the presence of the authorized inspector of the Engineer. The asphalt cement shall comply with the following requirements: