All new off-street parking facilities shall be paved with asphalt concrete or portland cement concrete and shall be designed and constructed in accordance with the standards and procedure herein established.
(A) Asphalt concrete pavement.
(1) General design requirements.
(a) Asphalt concrete pavements shall consist of specified thickness of asphalt concrete surfaces course and a base course, or courses, all constructed on prepared subgrade. Pavement thickness required shall be determined from Table 1 of this section of the appropriate subgrade soil and traffic use.
(b) Paved areas shall be so designed and constructed that water will quickly drain from the surface and be conducted away from the area through approved system. Transverse and/or longitudinal slopes of not less than 5/8-inch in ten feet shall be provided. For large pavement areas, approved catch basins and storm drainage systems shall be provided.
(c) When the pavement includes a granular base, and the pavement is not constructed over granular subgrade, perimeter subsurface drainage shall be provided to prevent lateral flow of water into the base course and to provide for removal of seepage water that may enter the base.
THICKNESS REQUIREMENTS OF SURFACE AND BASE COURSES FOR AUTOMOBILES AND TRUCK PARKING FACILITY PAVEMENTS (1)
Thickness of Surface and Base - Inches Asphalt Base | ||||
Type of Vehicle | Soil Classification | Type I of II | Type III or IV | Granular Base |
Thickness of Surface and Base - Inches Asphalt Base | ||||
Type of Vehicle | Soil Classification | Type I of II | Type III or IV | Granular Base |
Automobile Parking Facilities | A | 1-4 | 2-4 | 3-4 |
B | 1-5 | 2-5 | 3-6 | |
C | 1-6 | 2-6 | 3-8 | |
Truck Parking Facilities | A | 1-6 | 2-6 | 4-6 |
B | 1-7 | 2-7 | 4-8 | |
C | 1-8 | 2-8 | 4-10 | |
(1) Thickness of surface and base is shown for each soil classification and street classification. The first number indicates the minimum thickness of asphalt concrete which may be comprised of asphalt concrete surface course, Type I or II, if the surface course does not exceed two inches when surface thickness is more than two inches, asphalt concrete Base I or II, as specified in Table 2, may be used for all but the upper one-inch wearing course which must be asphalt concrete surface course I or II, as specified in Table 2. The second figure indicates the thickness of base course of the type indicated. For example, 1-4 indicates one inch surface and four inches base.
(2) Soils are classified into three groups indicating their relative effectiveness as subgrade.
A - Granular soils that drain well; sand, gravel, or combination of sand and gravel.
B - Silty clays, or lean clays, that retain considerable strength when wet. These are average subgrade soils.
C - Heavy clay soils that lose most of their strength when wet.
TABLE 2 COMPOSITION LIMITS FOR ASPHALT MIXTURES | ||||||
Percent Passing by Weight | ||||||
Asphalt Concrete | Asphalt Treated Base | |||||
SIEVE SIZE Base I | Base II | Surface I | Surface II | Base III | Base IV | |
1-1/2" | 100 | - | - | - | 100 | - |
1" | 85-100 | 100 | - | - | - | - |
3/4" | - | 80-100 | - | - | 70-100 | 100 |
½" | 50-80 | - | 100 | 100 | - | |
3/8" | - | 54-76 | 80-100 | - | 40-80 | 70-100 |
No. 4 | 30-50 | 37-57 | 55-75 | 75-95 | - | - |
No. 8 | 25-45 | 25-45 | 35-60 | 60-85 | 25-60 | 40-100 |
No. 16 | 15-35 | 15-35 | 25-50 | 45-70 | - | - |
No. 50 | 5-20 | 5-20 | 9-21 | 15-40 | 5-30 | 15-50 |
No. 100 | 3-10 | 3-10 | 5-14 | 5-25 | 3-15 | 5-25 |
No. 200 | - | - | 3.7 | 4-10 | - | |
% Asphalt | 3.5-6.0 | 4.0-7.0 | 5.0-8.0 | 6.0-9.0 | 3.5-6.0 | 4.0-8.0 |
(4) Successive layers of the pavement shall be offset from the edge of the underlying layer a distance equal to the course thickness of the lower layer except when abutting existing construction. When the asphalt layers of the pavement abut a
foundation, barrier curb or similar vertical surface, the abutting surface shall be heavily painted with asphalt prior to construction of the asphalt course. The surface course shall be finished 1/4-inch above adjacent flush construction to permit proper compaction.
(2) Construction materials and procedures.
(a) Subsurface drainage.
1. Drainage tile, six-inch perforated tile or other approved types of similar capacity, where required by the
shall be bedded at a depth of not less than 12 inches below the bottom elevation of the granular base course. Aggregate for bedding and backfill shall all pass a 3/8-inch sieve and have not more than 5% passing a No. 200 sieve. The slope of subsurface drains shall be not less than six inches per 100 feet. All such drains shall be properly connected to outlet drains.
2. All catch basins, in pavement with granular base, shall be constructed with weep holes, at subbase level, to provide for drainage of seepage water from the granular layer. Weep holes shall be constructed of pipe, or other material, having an opening not less than 1.5 inches clear opening. Suitable provision shall be made to prevent clogging of the opening. Three or more weep holes shall be suitably located around the perimeter of each catch basin.
(b) Base courses shall consist of one or more of the following materials. Construction procedures shall conform to the requirements applicable to the base course selected.
1. Asphalt concrete base course. Materials and construction shall conform to the current requirements of the Kentucky Bureau of Highways Specifications for Asphalt Concrete Base Course, Class I, except as noted herein:
a. Composition requirements of the mixture shall conform to the gradation limits for Asphalt Concrete H Base Course I or II set forth in Table 2 of this section. Asphalt content used shall fall within the range shown and shall be approved by the
.
b. Uncrushed gravel and natural sand may be used as aggregate provided all other requirements of the specification are compiled with.
2. Asphalt treated base course. Materials and construction procedures shall conform to the following requirements:
a. Aggregates may be crushed or uncrushed material conforming to the gradation requirements, shown in Table 2 of this section for either Base III or Base IV. The aggregate shall be composed of hard durable particles and shall contain no more than a total of 5% deleterious substances. In addition, the sand equivalent of the aggregate shall not be less then 25% when tested in accordance with AASHO Designation: T 1765. The contractor shall set a single gradation and asphalt content, within the specified limits, as the job mix formula to be used on the project. This formula must be approved by the
, prior to use. Gradation and asphalt content may vary during construction within the following tolerances:
% Passing 3/4 inch or 3/8 inch | sieve ± 10% |
% Passing No 8 Sieve | ± 8% |
% Passing No. 50 Sieve | ± 6% |
% Passing No. 100 Sieve | ± 3% |
% Asphalt |
b. Other construction requirements shall conform to those specified by the Kentucky Bureau of Highways for asphalt concrete except that a gradation unit on the plant shall not be required provided the aggregate can be controlled by other means to produce a consistently uniform gradation.
3. Crushed stone base course.
a. Crushed stone base course shall conform to all the current requirements of the Kentucky Bureau of Highways for Dense Graded Aggregate Base Course.
(c) Asphalt concrete surface course. Materials and construction shall conform to the current requirements of the Kentucky Bureau of Highways for Asphalt Concrete surface, Class I. Surface course mixture composition may conform to requirements of either Surface Course I or II as set forth in Table 2 of this section. Minimum course thickness shall be as stated in Table 1 of this section.
(d) Asphalt prime and tack coat.
1. Asphalt prime shall conform to the Kentucky Bureau of Highways' requirements for Cutback Asphalt Emulsion Primer Type L. Prime shall be applied to the surface of granular base course at a rate of 0.20 to 0.40 gallons per square
, as directed by the County Engineer, in conformance with requirements of the referred to specification.
2. Tack coat shall consist of SS-lh, meeting the current requirements of the Kentucky Bureau of Highways. It shall, when directed by the
, be diluted with equal parts of water. Application equipment and procedure shall conform to the requirements of the Kentucky Bureau of Highways for Tack Coat. Tack coat shall be applied, upon direction of the
, to the surface of asphalt courses that have become dusty or dry from traffic use before the subsequent course could be placed or in other circumstances when the
so directs.
(B) Soil cement base course (with asphalt concrete surface).
(1) Description. Soil-cement base course shall consist of soil and cement uniformly mixed, moistened, compacted, finished, and cured in accordance with the specifications herein, and it shall conform to the lines, grades, thickness, and typical cross section shown on the plans.
(2) Materials.
(a) Cement. Cement shall comply with the latest specifications for cement, AASHO M85, M134, M151; or ASTM C150, C175, C205; or Federal SS-C192b, SS-C-218 for the type specified. One cubic foot of portland cement shall be considered to weigh 94 pounds and one barrel of cement shall be considered to weigh 376 pounds.
(b) Water. Water shall be free from substances deleterious to the hardening of the soil- cement.
(c) Soil. Soil shall consist of the material existing in the area to be paved, of approved selected soil, or of a combination of these materials proportioned as direct. The soil shall not contain gravel or stone retained on a three-inch sieve or more than 45% retained on a No. 4 sieve.
(3) Construction methods.
(a) Preparation.
1. Unsuitable soil or material shall be removed and replaced with acceptable soil.
2. The subgrade shall be firm and able to support without displacement the construction equipment and the compaction hereinafter specified. Soft or yielding subgrade shall be corrected and made stable, before construction proceeds.
(b) Pulverization. The soil shall be so pulverized that, at the completion of moist-mixing, 100% by dry weight passes a one-inch sieve and a minimum of 80% passes a No. 4 sieve, exclusive of gravel or stone retained on the sieves.
(c) Cement application, mixing, and spreading.
1. Mixing of the soil, cement, and water shall be accomplished either by the mixed-in- place or the central-plant-mixed method.
2. No cement or soil-cement mixture shall be spread when the soil or subgrade is frozen or when the air temperature is less than 40° F. in the shade.
3. The percentage of moisture in the soil, at the time of cement application, shall not exceed the quantity that will permit a uniform and intimate mixture of soil and cement during mixing operations; and it shall not exceed the specified optimum moisture content for the soil-cement mixture.
4. Any soil-and-cement mixture that has not been compacted and finished shall not remain undisturbed for more than 30 minutes. The soil-cement base course shall have a thickness of not less than six inches.
(d) Compaction.
1. At the start of compaction, the percentage of moisture in the mixture and in unpulverized soil lumps, based on oven-dry weights, shall not be below or more than two percentage points above the specified optimum moisture content and shall be less than that quantity which will cause the soil-cement mixture to become unstable during compaction and finishing. The specified optimum moisture content and density shall be determined in the field by a moisture-density test, AASHO T134-57 or ASTM D558-57, on representative samples of soil- cement mixture obtained from area being processed.
2. Prior to the beginning of compaction, the mixture shall be in a loose condition for its full depth. The loose moisture then shall be uniformly compacted to the specified density within two hours. During compaction operations, shaping may be required to obtain uniform compaction and required grade and cross section.
(e) Finishing.
1. After compaction the surface of the soil-cement shall be shaped to the required lines, grades, and cross section. If necessary, during shaping operations, the surface of the base shall be lightly scarified to remove any tire imprints or smooth surfaces left by equipment. The resulting surface shall then be compacted to the specified density. Rolling shall be supplemented by broom-dragging if required.
2. The moisture content of the surface material must be maintained at not less than its specified optimum moisture content during finishing operations. Surface compaction and finishing shall be done in such a manner as to produce, in not longer than two hours, a smooth dense surface free of compaction planes, cracks, ridges, or loose materials.
3. Any portion of the soil-cement that has a density of five pounds or more below that specified shall be corrected or replaced to meet these specifications.
(f) Curing.
1. After the soil-cement has been finished as specified herein, it shall be protected against drying for seven days by the application of bituminous material. The curing material shall be applied as soon as possible but not later than 24 hours after completion of finishing operations. The finished soil-cement shall be kept continuously moist until the curing material is placed.
2. The bituminous material specified shall be uniformly applied to the surface of the completed soil-cement at the rate of approximately 0.2 gallons per square
with approved heating and distributing equipment.
3. At the time the bituminous material is applied the soil-cement surface shall be dense, shall be free of all loose and extraneous material, and shall contain sufficient moisture to prevent penetration of the bituminous materials. Water shall be applied in sufficient quantity to fill the surface voids of the soil-cement immediately before the bituminous curing material is applied.
4. The curing material shall be maintained by the contractor during the seven-day protection period so that all of the soil-cement will be covered effectively during this period.
5. Sufficient protection from freezing shall be given the cement for seven days after its construction and until it has hardened.
(g) Surfacing. Asphaltic concrete shall be applied to the soil-cement base course as regulated in division (A)(2)(c) of this section.
(C) Concrete parking areas.
(1) General requirements. Thickness of concrete parking shall be:
(a) A minimum of five inches for passenger cars and panel or pick-up truck parking.
(b) A minimum of six inches for driveways accommodating light trucks and for light truck parking.
(c) A minimum of seven inches for heavier commercial or industrial needs.
(2) General requirements. Concrete mix (for areas subject to freeze-thaw conditions.)
(a) Minimum cement content, 564 pounds per cubic
(six U.S. bags).
(b) A maximum size of aggregate, 1-1/2 inches.
(c) Maximum water content, 0.49 pounds per one pound of cement (5.5 gallons per bag).
(d) Maximum slump, four inches.
(e) Air entrainment:
Maximum Size Aggregate (inches) | Entrained Air (Percent) |
1-1/4
|
5 ± 1
|
3/4, 1
|
6 ± 1
|
3/8, ½
|
7-1/2 ± 1
|
(3) Construction procedures.
(a) All soft and yielding material and other portions of the subgrade which will not compact readily when rolled or taped shall be removed and replaced with suitable material placed and compacted. The subgrade shall be thoroughly compacted with suitable equipment so as to have uniform density at moisture contents of not less than standard optimum CAASHO-T98).
(b) Longitudinal joint spacing shall not exceed 12.5 feet.
(c) Transverse joint spacing shall be at regular intervals of 20 feet.
(d) All transverse construction joints shall have a depth equal to one-fourth of the pavement thickness.
(e) Form offsets at radius points shall be at least two feet.
(f) Pavement joints must be continuous through the curbs.
(g) Where curbs are required they shall be cast integrally.
(h) The pavement shall be struck-off, consolidated, and finished to the grades shown on the plans. All catch basins and manhole castings shall be boxed out and separated from the pavement with expansion joint material. All except premolded or sawed joints shall be edged with a tool having a maximum radius of 1/8 inch. Sawed and formed joints shall be cleaned and sealed before opening to traffic. Final surface texture shall be that obtained with a burlap drag. Curing shall be that obtained with a uniform coverage of white membrane curing compound or by seven-day coverage of white polyethylene or waterproof paper. The completed pavement shall be closed to traffic for seven days.
(Ord. 0-11-82, passed 11-3-82) Penalty, see § 154.999