New Franklin Street Construction Specifications for Seven Inch Penetration Base ordinance (§ 510.020)

All streets of the City of New Franklin, hereafter constructed including streets dedicated to public use as a part of any subdivision hereafter accepted by the City, shall be built in such a manner as to conform to the following minimum specifications and requirements:

1. Description.

a. The asphalt macadam base shall consist of mineral aggregate and asphalt cement combined as hereinafter specified and shall be laid upon the prepared subbase to a finished thickness of not less than seven (7) inches.

b. The method of construction shall proceed substantially as follows:

(1) One (1) inch to three-fourth (¾) inch covering of screens shall be placed and rolled.

(2) A three (3) inch lift of coarse aggregate shall be placed and spread to an even contour, rolled and treated with hot asphalt cement.

(3) A second (2nd) three (3) inch lift of coarse aggregate shall be spread and brought to an even contour, rolled and checked to insure the finished base has a thickness of seven (7) inches and then it shall be treated with hot asphalt cement applied as hereinafter specified.

(4) The surface voids shall be filled by applying and rolling in sufficient fine aggregate.

(5) A two (2) inch layer of hot mix asphaltic concrete shall be applied by means of an approved asphalt finishing machine.

c. All materials and methods of construction shall conform to the requirements of those specifications.

2. Materials. The mineral aggregate shall consist of crushed limestone. It shall be reasonably uniform quality throughout and shall be clean and free from an excess of dust and flat or elongated stone. The crushed limestone shall have a percent of wear by the Los Angeles abrasion machine test of not more than fifty (50).

3. Approval of materials. Prior to use, samples of all materials proposed to be employed under those specifications shall be submitted to the City Services Director for test and analysis and no material shall be used until it has been approved by the City Services Director.

4. Construction.

a. Prior to the construction of the surface course, the base shall be brought to a uniform grade, plus or minus one-tenth (±1/10) of a foot and cross-section. It shall be thoroughly compacted ninety-five percent (95%) and shall be cleaned of loose material and foreign matter.

b. Any soft spots shall be removed. Then, one (1) inch to three-fourth (¾) inch covering of screening shall be placed and rolled. The coarse aggregate of 3" to 2½" stone shall then be spread upon the subbase in a uniformly loose layer of correct thickness three (3) inches. Suitable precautions shall be taken to prevent the aggregate from becoming mixed or coated with dirt or other objectionable matter before and after spreading.

c. The coarse aggregate shall then be dry rolled with a power driven steel wheel roller weighing not less than ten (10) tons and with a minimum weight of three hundred (300) pounds per inch width of rear wheel. Rolling shall start longitudinally at the sides and proceed toward the center of the pavement, overlapping on successive trips by at least one-half (½) of the width of the rear wheel. The compacted coarse aggregate shall then be tested to insure that it possesses a firm, even surface, true to cross sections shown on the plans and presents a texture which will allow uniform penetration of the asphalt cement. If any irregularities appear during or after rolling, they shall be remedied by loosening the surface and removing or adding coarse aggregate, as may be required, after which the area disturbed, including the surrounding surface, shall be rolled until compacted satisfactorily to a uniform surface. All coarse aggregate which becomes coated or mixed with dirt or foreign substances prior to the application of asphalt cement shall be removed and replaced with clean aggregate of the same kind and compacted as specified.

d. The pressure distributor used for applying asphalt cement shall be equipped with pneumatic tires and shall be so designed and operated as to distribute the asphalt cement in a uniform spray without atomization in the amount and between the limits of temperature specified. It shall be equipped with a fifth (5th) wheel speed tachometer registering feet per minute and so located as to be visible to the truck driver to enable him/her to maintain the constant speed required for application at the specified rate.

e. The pump shall be operated by a separate power unit or by the truck power unit. It shall be equipped with a tachometer registering gallons per minute passing through the nozzles and readily visible to the operator. Suitable means for accurately indicating at all times the temperature of the asphalt cement shall be provided. The thermometer well shall be so placed as not to be in contact with a heating tube.

f. The distributor shall be so designated that the normal width of application shall be not less than six (6) feet, with provision for the application of lesser width when necessary. If provided with heating attachments, the distributor shall be so equipped and operated that the asphalt cement shall be circulated or agitated throughout the entire heating process.

g. Upon each lift of rolled coarse aggregate, 85-100 penetration asphalt cement shall be applied uniformly at the rate of two (2) gallons per square yard at application temperature with an allowable tolerance of one-tenth (0.1) gallon either way. Asphalt cement shall be applied only when the course is thoroughly dry for its entire depth and, unless otherwise permitted by the City Services Director, when the air temperature in the shade is not less than forty degrees Fahrenheit (45°F). Application of the asphalt cement shall be made by means of a pressure distributor as described above.

h. The asphalt cement shall be heated in tanks designed to secure uniform heating of the entire contents and, immediately prior to application, shall be brought to a temperature of three hundred fifty degrees Fahrenheit (350°F) to four hundred degrees Fahrenheit (400°F) as directed by the City Engineer. The contractor shall provide all necessary facilities for determining the temperature of the asphalt cement during heating and prior to application. A narrow spout pouring pot or hand spray shall be used to apply asphalt cement necessary to touch up all spots unavoidably missed by the distributor.

i. The second (2nd) lift of crushed stone shall be put in place exactly as the first (1st) lift as described above, the one (1) exception being the size of stone shall be 2" to 1½" rather than 3" to 2½" as used in the first (1st) lift. Asphalt requirements shall be the same as upon the first (1st) lift. Immediately after the asphalt cement has been applied to the second (2nd) lift of coarse aggregate, there shall be spread over its surface a light sprinkling of clean, dry three-fourth (¾) inch aggregate at fifteen (15) pounds to the square yard and drag broomed. The rolling shall continue, not exceeding maximum rolling speed of three (3) miles per hour, until the pavement is firmly bound together and the surface is hard and smooth and shows no perceptible movement under the roller. The aggregate for this purpose shall be applied by means of a mechanical spreader and shall be ready for immediate use before any asphalt cement shall be applied. It shall be applied ahead of truck or roller wheels.

5. Mix. The asphalt concrete surfacing shall consist of two (2) inches, after compaction, hot mix asphaltic concrete to meet the specifications that follow:

6. Type of equipment. All equipment to meet the Missouri State Highway Department specifications, including the mix plant, the roller (ten (10) ton) and the asphalt finishing machine.

7. Method of rolling. Break down rolling shall be immediately behind the finishing machine. After mix has cooled, rolling to continue until roller marks are removed.