Copyrighted by SPRINGDALE CODE & Municipal Code Corporation, 1998.
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Sec. 110-54. Minimum standards for streets.
Plans and specifications for proposed streets shall equal the following minimum standards and be in accordance with the standards set forth in the "City of Springdale, Arkansas Standard Details for Street and Drainage Construction.
(1) Clearing and grubbing:
a. All trees, stumps, roots and other obstructions, not designated to remain, shall be cleared and/or grubbed in such a manner so as to not cause injury to other things designated to remain. Stump holes shall be filled with suitable material and compacted.
b. If material is to be burned, it shall comply with all applicable laws and ordinances, and shall be under the constant care of competent watchmen.
(2) Roadway excavation and embankment: Suitable material shall consist of soil or a mixture of soil, stone or gravel. It shall be free of sod, logs, stumps, roots and other deleterious matter, and it shall be capable of forming a stable embankment when compacted.
a. All suitable material obtained during the excavating operations shall be used in the construction of the roadway embankment and subgrade, and all unsuitable material shall be used behind the curb or hauled to an approved waste area.
b. All street cuts and grades shall conform to those shown on the approved plans or approved plans or approved plan changes.
c. Sod and vegetative matter shall be removed from the surface upon which an embankment is to be placed.
d. Roadway embankments shall be constructed in layers not to exceed eight inches (loose measurement), and shall be compacted at optimum to three percent above optimum moisture for that particular soil to a density, as determined by AASHTO T 191 (sand cone method) or AASHTO T 238 (nuclear method), of not less than 95 percent of the maximum density obtained by AASHTO T 99 (standard proctor). In areas where solid rock is encountered, it shall be excavated to a depth of eight inches below subgrade elevation and replaced with approved material.
e. Rock obtained during excavation operations may be placed in layers not exceeding 30 inches. The rock shall be placed in a manner that the voids between the rock fragments are filled with suitable material. The top 12 inches of the finished subgrade shall not contain rock over four inches in its greatest dimension.
f. Embankment which is adjacent to structures and inaccessible to normal compaction equipment shall be placed in four-inch (loose measurement) layers and compacted to 95 percent of maximum density as obtained by AASHTO T 99. The material shall be compacted with mechanical equipment where it is inaccessible to normal compaction equipment.
(3) Subgrade:
a. In fill sections where A-5, A-6 or A-7 soils are encountered which have an LL greater than 40 or a PI greater than 17, an approved imported embankment material shall be used in the top two feet of the subgrade; or the top eight inches of the subgrade treated with lime to reduce the PI to ten or less. In cut sections where A-5, A-6 or A-7 soils are encountered which have an LL greater than 40 or a PI greater than 17. The subgrade shall be over excavated and replaced with approved fill material to a depth as required by the director of planning and community development or his/her designated representative or the top eight inches of the subgrade shall be treated with lime to reduce the PI to ten or less. These requirements are in addition to the pavement section required based upon the soil type of the existing subgrade material.
b. The subgrade shall be prepared and maintained in such a manner as to ensure a firm foundation that is stable and free from dust pockets, wheel ruts and other defects.
c. The subgrade shall be compacted to a density, as determined by AASHTO T 191 or T 238, of not less than 95 percent of the maximum density obtained by AASHTO T 99. This shall be accomplished by scarifying as necessary, shaping and compacting to the required grade and section at optimum to three percent above optimum moisture content.
d. The finished subgrade shall be string lined to within plus or minus one-half inch of the finished grade and typical section shown on the approved plans.
(4) Utility crossings:
a. All utility lines, including service lines, shall be laid, backfilled and compacted with class seven base or other material suitable to the planning and community development director or his/her designated representative before the curb and gutter is constructed.
b. Any service or utility line crossings not placed before the pavement and curb and gutter are constructed shall be installed by boring. The procedures shall be approved by the planning and community development director or his/her designated representative, and a permit and a cash deposit or bond is required as provided in section 110-86.
(5) Curb and gutter:
a. The subgrade shall be shaped and compacted to the required grade and section as shown on the plans. All unsuitable material, including soft and yielding material, shall be removed and replaced with suitable material and compacted to the proper density.
b. All curbs and gutters shall be constructed in accordance with the details contained in the City of Springdale, Arkansas Standard Details for Street and Drainage Construction.
c. If the subgrade or drainage blanket is dry, it shall be wetted just prior to placing the concrete so the moisture will not be pulled from the concrete.
d. Curb and gutter shall not be placed on frozen subgrade. Additionally, the ambient air temperature must be 40 degrees at time of placement.
e. Curb and gutter shall be cured at 50 degrees ambient temperature for a minimum of five days.
f. All concrete shall be cured using wet burlap or a membrane curing compound meeting the requirements of AASHTO M 148, type 1-D or type two. The exposed concrete, immediately after finishing, shall be covered with one of the curing materials listed above and shall be kept continuously and thoroughly wet for a period of not less than five days after the concrete is placed. Membrane curing does not require the application of additional moisture. Satisfactory equipment and means to properly control and assure the direct application of the curing solution on the concrete surface shall be provided so as to result in a uniform coverage at a rate of one gallon for each 125 square feet of area.
g. After the concrete curb and gutter has set, the area behind the curb shall be partially backfilled before the base material is placed and compacted.
(6) Crushed stone base course:
a. The base material shall consist of a mixture of crushed stone and natural fines, and shall have a percent loss by the Los Angeles Test AASHTO T 96 not greater than 45. The material shall contain no more than five percent by weight of deleterious matter. The crushed stone base material shall meet the following gradation requirements:
The fraction passing the No. 200 sieve shall not be greater than two-thirds of the fraction passing the No. 40 sieve. The fraction passing the No. 40 sieve shall have an LL not greater than 25 and a PI not greater than six.
b. The depth of the crushed stone base course shall be within plus or minus one-half inch of the approved design depth. The average of all depth measurements shall not be less than the required depth, and any depth in excess of plus one-half inch shall not be used in computing the average depth.
c. The base course shall be placed on an approved subgrade and spread uniformly in such a manner that no segregation of course and fine particles will occur. Under no circumstances shall the base course be placed on a frozen subgrade.
d. The base course shall be constructed in layers not exceeding eight inches of compacted depth at substantially optimum moisture. The contractor must be capable of compacting the material at this depth; otherwise the material shall be placed and compacted in layers. The density of the compacted material in each layer, as determined by AASHTO T 191 or T 238, shall not be less than 95 percent of the maximum density as obtained by AASHTO T 180, (modified proctor).
e. The finished base course shall be string lined to within plus or minus one-half inch of the design section.
(7) Cement-treated crushed stone base: Cement-treated crushed stone base shall meet the requirements of the state highway commission's standard specifications for highway construction, (hereafter, referred to as the AHTD Standard Specification), for cement-treated crushed stone base course, with the following exceptions:
a. The cement-treated crushed stone base shall consist of aggregate meeting the requirements for class seven, three percent to six percent by weight of type I Portland cement, and water at plus or minus one percent of optimum. The percent of cement and water shall be determined from laboratory tests. The specimens of aggregate, cement and water must develop a compressive strength of at least 650 psi in seven days. The type of asphalt used for protection and cover for the cement-treated base will be at the option of the contractor, subject to the approval of the director of planning and community development division or his/her designated representative.
b. The cement-treated base shall not be mixed or placed while the atmospheric temperature is below 35 degrees Fahrenheit within 24 hours, or when the weather is foggy or rainy. During cold weather the cement-treated base shall be protected for seven days. When the temperature is expected to drop below 35 degrees Fahrenheit, a sufficient supply of hay, straw, or other material suitable for cover and protecting the previously placed material shall be used. Any cement-treated base, which has been damaged by freezing, or otherwise, shall be removed and replaced at the contractor's expense.
c. The crushed stone base, cement and water shall be mixed in a pug mill-type central plant, a self-propelled or self-powered traveling mixer equipped with a rotor or other approved type mixer that will thoroughly mix the base and cement at the required depth and at or near the optimum moisture content, or by other methods approved by the planning and community development director or his/her designated representative.
d. The cement-treated crushed stone base shall be placed on an approved subgrade and spread uniformly in such a manner that no segregation of coarse and fine particles will occur. Under no circumstances shall the base course be placed on a frozen subgrade.
e. The cement-treated crushed stone base shall be constructed in layers not exceeding six inches of compacted depth at substantially optimum moisture. The density of the cement-treated crushed stone base, as determined by AASHTO T 191 or T 238, shall not be less than 95 percent of the maximum density as obtained by AASHTO T 180.
f. After the cement-treated base has been finished, it shall be protected from drying by the application of approximately two-tenths gallon per square yard of bituminous material. The bituminous material shall be applied as soon as possible, but in no case later than 24 hours and maintained for seven days.
g. No vehicles shall be allowed on the cement-treated base during the seven-day curing period. Finished portions of cement-treated base that are used by construction equipment shall be protected in such a manner to prevent equipment from marring or damaging the completed work. Any damage to the cement-treated base resulting from vehicles shall be removed and replaced at the contractor's expense.
h. The depth of the cement-treated base shall be within plus or minus one-half inch of the required depth. The average of all depth measurements shall not be less than the required depth, and any depth in excess of plus one-half inch shall not be used in computing the average depth.
i. The finished cement-treated crushed stone base course shall be string lined to within plus or minus one-half inch of the typical section.
(Ord. No. 3258, § 1, 11-12-02)
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Total percent retained by weight Size of Sieve Class 7 Base 1 1/2" 0 3/4" -- 3/4" 10--50 #4 50--75 #40 70--90 #200 90--97