Loading...
Driveways shall meet the standards for driveway design as defined in this section. Concrete thickness for drives within city right-of-way shall be a minimum of six inches. Asphalt thickness for residential drives within city right-of-way shall be two inches of asphalt over four inches of compacted Class 7 Aggregate Base Course. Asphalt thickness for commercial drives within city right-of-way shall be three inches of asphalt over six inches of compacted Class 7 Aggregate Base Course. The slope of the driveway shall match the cross slope of the sidewalk which shall have a cross slope of no more than 2%.
(Ord. 2009-11-347, passed 11-3-09; Am. Ord. 2010-06-356, passed 6-1-10; Am. Ord. 2018-11-816, passed 11-6-18)
ARTICLE 90.500 PAVEMENT DESIGN
(A) Street pavement sections shall be either flexible type with an asphalt concrete surface or rigid type consisting of a Portland cement concrete section and surface. Curb and gutter shall be Portland cement concrete.
(B) Flexible pavements may be composed of a crushed stone base course with an asphaltic concrete surface.
(C) Rigid structures shall be full depth Portland cement concrete to the designed thickness with a crushed stone drainage/leveling course of no less than three inches.
(D) Pavement sections shall be designed in accordance with the procedures and criteria of the AASHTO Guide for Design of Pavement Structures, latest edition, and the criteria contained herein. Any conflicts shall be resolved in favor of the more stringent criteria resulting in a stronger and deeper pavement section.
(E) References to various materials, testing and construction shall refer to the latest editions of AASHTO, ASTM, and the Standard Specifications of the Arkansas State Highway and Transportation Department.
(Ord. 2009-11-347, passed 11-3-09; Am. Ord. 2010-06-356, passed 6-1-10; Am. Ord. 2018-11-816, passed 11-6-18)
All pavement materials, construction methods, standards, time and temperature constraints, seasonal constraints, and performance requirements shall be in accordance with the 2003 edition of the ARDOT Standard Specifications for Highway Construction, and this set of requirements (Article 90.500, Pavement Design, and Article 90.600, Utilities and Utility Crossings) unless specifically approved otherwise in writing by the city for a specific and individual exception. All testing shall be in accordance with Article 90.800, Inspections and Testing.
(Ord. 2009-11-347, passed 11-3-09; Am. Ord. 2010-06-356, passed 6-1-10; Am. Ord. 2018-11-816, passed 11-6-18)
(A) Subgrade soils shall be all materials used for subgrade including in-situ materials and fill materials. Subgrades for pavement shall be stabilized by mechanical compaction or by other methods approved in writing by the City Engineer. Stabilization methods such as fabrics and chemical stabilization may be submitted for approval when supported by engineering data and calculations to substantiate the adequacy of the stabilization procedure.
(B) The top 24 inches of the subgrade shall be a material not susceptible to frost action unless modified with cement, lime or another method approved specifically by the City Engineer to resist frost action (Soils classified as A-4 and A-5, including sandy silts, fine silty sand or lean clays are highly susceptible to frost action).
(C) In-situ soils meeting the requirements outlined in these specifications may be utilized as subgrade material. In-situ soils used as subgrade shall be scarified to a minimum depth of eight inches below finish subgrade, recompacted, and tested as described in § 90.800.5 of these specifications. Fill material for subgrade shall be placed in lifts not to exceed eight inches compacted depth.
(D) Methods and procedures for establishing the total depth of soil replacement and/or modification shall be specified by the design engineer and included in the project plans and specifications. The minimum depth of replacement shall be 24 inches in the absence of engineering data showing otherwise.
(E) A “bridge lift” is defined as material that meets the requirements of these standards and is utilized to span areas of unsuitable material that lie below the 24 inch subgrade requirement. Bridge lift depth shall be determined by a geotechnical firm but in no case shall the lift be less than 24 inches in depth. A bridge lift will be placed in one lift in its entirety or as otherwise directed by the geotechnical firm and approved by the City and will require a “wheel roll” test prior to construction of the final 24 inch subgrade. Additional bridge lift depth may be required by the city dependent on field conditions.
(F) The adequacy of in-situ soils and fill materials as pavement subgrade shall be evaluated based upon the soils classifications, liquid limit, plasticity index and California Bearing Ratio (CBR) values.
(G) All soils with a liquid limit greater than 40, or a plasticity index greater than 15, or a CBR value of less than eight shall be undercut and removed from the street section or improved by a designed method of stabilization accepted by the City Engineer.
(H) Soils with a CBR of eight or greater, and classified as GM or GC soil, shall be accepted as “Hillside” material and no further treatment or upgrade will be required.
(I) Subgrade compaction requirements including the moisture density requirements shall be shown both on the plans and in the specifications. (Compaction shall be a minimum of 95% standard proctor. Moisture content shall be + 3% optimum moisture unless otherwise supported by site specific geotechnical data and approved in writing by City Engineer).
(J) Sampling and testing of subgrade materials shall be as set forth in § 90.500.8 of these standards.
(K) Pavement designs that utilize a subbase course shall include test data and specifications for the subbase material in the calculations submitted to the City Engineer for review and approval.
(Ord. 2009-11-347, passed 11-3-09; Am. Ord. 2010-06-356, passed 6-1-10; Am. Ord. 2018-11-816, passed 11-6-18)
Loading...