ROADWAY DESIGN AND CONSTRUCTION STANDARDS

Transcription

1 ROADWAY DESIGN AND CONSTRUCTION STANDARDS GENERAL ROADWAY DESIGN AND CONSTRUCTION STANDARDS The Engineer of Record is responsible for all roadway and bridge design data and calculations STANDARD DETAILS Construction shall conform to the standard details in this manual ROADWAY DESIGN AND CONSTRUCTION CRITERIA Roadway design and construction criteria shall conform to all criteria contained herein, including those criteria contained in the following publications: a) Florida DOT - Manual of Uniform Minimum Standards for Design, Construction and Maintenance for Streets and Highways, latest edition. (b) Florida DOT - Procedures Manual for Flexible Pavement Design, latest edition. (c) U.S. Department of Transportation, Federal Highway Administration - Manual on Uniform Traffic Control Devices for Streets and Highways, latest edition. (d) Florida DOT - Standard Specifications for Road and Bridge Construction, latest edition. (e) AASHTO - Standard Specifications for Highway Bridges, latest edition. (f) Florida DOT - Roadway and Traffic Design Standards, latest edition. Publications listed shall be considered as an integral part of this manual. Construction plans submitted for review shall include design data and calculations for structures and roadways RIGHT-OF-WAY Minimum right-of-way widths shall be as listed below. Additional right-of-way may be necessary in order to provide for adequate drainage facilities (drainage easements shall not run along front lot lines). Roadway Classification Urban Section Rural Section Local Street 50' min. Collector Street 60' min. Industrial Park 60' min./80' preferred 100' min CLEARING ROADWAY DESIGN AND CONSTRUCTION STANDARDS - 2

2 All roadway rights-of-way shall be cleared and grubbed in accordance with the Florida DOT Standard Specifications for Road and Bridge Construction, latest edition. Selective clearing and grubbing are prohibited unless approved by Community Development. The roadside recovery area shall be per Florida DOT specifications SUBSOIL INVESTIGATION FOR ROADWAYS A subsoil investigation report shall be submitted with the road, bridge and drainage plans and shall include: (a) Seasonal high and existing ground water elevation data. (b) Borings a minimum of 5.0 feet below the profile grade at a maximum of five hundred (500) intervals to determine the soil classification in accordance with AASHTO M Additional borings may be made as necessary to determine limits of unsuitable material. Depth and extent of muck areas shall be determined. Handling of unsuitable material shall be determined by the Engineer of Record, subject to the approval of the City Engineer DESIGN CRITERIA FOR ROADWAY SUBGRADE (a) Requirements Roadway subgrade (except that subgrade for soil cement base shall be in accordance with the Florida DOT Standard Specifications for Road and Bridge Construction, latest edition, and in place soil within Group Classification A-4 through A-7 according to AASHTO M shall be removed to a depth of twelve (12) inches below the bottom of the soil cement base and replaced with soil acceptable to the Engineer of Record subject to the approval of the City Engineer) shall in no case have a depth, bearing ratio and density less than: Compacted Stabilized Limerock Type of Subgrade Bearing Minimum Development Depth Ratio Density Residential 9" 40 98% MODIFIED PROCTOR Industrial 12" 40 98% MODIFIED PROCTOR (b) Construction The construction of the stabilized roadbed, including compaction, shall conform to the Florida DOT Standard Specifications for Road and Bridge Construction, latest edition. The use of a reinforcing ROADWAY DESIGN AND CONSTRUCTION STANDARDS - 3 fabric may be used below the subgrade to help obtain the required compaction. The fabric shall meet the specifications of Florida DOT, Section 985-1(2). (c) Testing

3 Testing for the subgrade bearing capacity and compaction shall be located no more than five hundred (500) feet apart and shall be staggered to the left, right, and on the centerline of the roadway. Test results shall be submitted by the Engineer of Record to the City Engineer when received by the Engineer of Record. When, in the judgment of the City Engineer, conditions warrant additional testing, the Engineer of Record will be advised in writing that additional tests will be required and the extent of such additional tests BASE COURSES FOR FLEXIBLE PAVEMENTS (a) Subject to the approval of the City Engineer, base course materials may be as follows: limerock, soil cement, concrete, asphalt or shell. All materials and construction shall conform to the Florida DOT Standard Specifications for Road and Bridge Construction, latest edition, Index No The Structural Number for any base course shall equal or exceed 1.00 and 1.44 for residential and industrial pavements, respectively. (b) Base materials and plant mixes are to be certified in accordance with the Florida DOT Standard Specifications for Road and Bridge Construction, latest edition. Base materials and plant mix certifications are to be submitted to the City Engineer by the Engineer of Record for review. (c) Soil cement base shall obtain a seven (7) day compressive strength of a minimum of 300 psi. In no case shall soil cement base thickness be less than seven (7) inches for residential development and ten (10) inches for industrial development. Test cores shall be taken at twenty-one (21) days, have a strength of a minimum of 450 psi, and be taken at locations of high ground water and other locations as deemed necessary by the Engineer of Record. Soil cement base shall have a seven (7) day minimum curing time prior to paving. (d) Testing Tests for base thickness and density shall be located no more than five hundred (500) feet apart and shall be staggered to the left, right, and on the centerline of the roadway. Test reports for thickness and density shall be submitted to the City Engineer by the Engineer of Record. When, in the judgment of the City Engineer, conditions warrant additional testing, the Engineer of Record will be advised in writing that additional tests will be required and the extent of such additional tests. ROADWAY DESIGN AND CONSTRUCTION STANDARDS - 4 (e) Prime and Tack Coats All bases shall be primed in accordance with the Florida DOT Standard Specifications for Road and Bridge Construction, latest edition. Tack coats shall not be required on primed bases, except on areas which have become excessively dirty and cannot be cleaned, or in areas where the prime has cured and lost all bonding effect. Tack coat material and construction methods shall conform to the Florida DOT Standard

4 Specifications for Road and Bridge Construction, latest edition SURFACE COURSE FOR FLEXIBLE PAVEMENTS (a) Requirements Surface courses for flexible pavements shall be Asphaltic Concrete Type S-1 and shall meet the following minimum thickness requirements as noted below: Type of Roadway Asphaltic Concrete Development Classification Surface Course Residential - urban Local Street 1½" Collector Street 1½" Residential - rural (e) Local Street Alternate Surface Course Industrial Local Street 2" Collector Street 2" (b) Material and Construction Asphaltic Concrete Type S-1, including prime and tack coats, shall conform to the Florida DOT Standard Specifications for Road and Bridge Construction, latest edition, for materials and method of construction. (c) All design calculations shall be submitted for review with construction plans and shall be in accordance with criteria as set forth in the State of Florida Procedures Manual for Flexible Pavement Design, latest edition. (d) Plant mix design certifications and/or coring tests of base and pavement may be required by the City Engineer. These tests will be requested in cases of base or pavement failure and will be at the expense of the developer. (e) Residential rural development will allow for alternate surface course material such as crushed concrete, milled asphalt material or stone as approved by the City Engineer provided all of the following conditions are met 1) RE or Farm zoning designation of ROADWAY DESIGN AND CONSTRUCTION STANDARDS - 5 property adjacent to the right-of-way to be developed 2) A maximum of seventy (70) vehicular trips per week, per dwelling unit anticipated with a maximum of five (5) dwelling units to be accessed by the right-of-way (d) That no special condition or drainage consideration would interfere with the use of an alternate surface course. Specifications for alternate surface courses are available from the Pinellas Park Engineering Services Division and 4) the alternate surface course material will not be permitted within 30 feet of a right-of-way, which has a paved roadway PORTLAND CEMENT CONCRETE PAVEMENT

5 (a) Scope of Work Rigid pavement consists of constructing a specified cement concrete paving on a prepared subgrade. The utilities and other items in and beneath the street must be properly coordinated with the construction of rigid pavement to avoid all conflicts. The work to be done shall include the furnishing of all supervision, labor, materials, equipment, and incidentals necessary for the proposed rigid pavement construction in accordance with the approved drawings and specifications. (b) Subgrade Preparation for Rigid Pavement General The bottom of the excavation for the pavement or top of the earth fill will be known as the pavement subgrade and shall conform to the lines, grade, and cross sections shown on the plans. Prior to placing the concrete, the subgrade shall be tested for conformity with the cross section shown on the plans. If necessary, material shall be removed or added as required to bring all portions of the subgrade to the correct elevation. It shall be thoroughly compacted to meet the requirements of Florida DOT Standard Specifications for Road and Bridge Construction, latest edition. Concrete shall not be placed on any portion of the subgrade which has not been tested for correct elevation. The subgrade shall be cleared of all loose material. At any time that trucks, construction equipment, or slipforming machines cause rutting or displacement of the subgrade materials, the subgrade shall be reshaped and compacted. The subgrade shall be in a moist condition at the time the concrete is placed. Subgrade Material The top six (6) inches shall be A-2, A-3, A-2-4 or a-2-5 in accordance with AASHTO M The top six (6) inches shall have a minimum limerock bearing ratio (LBR) of thirty (30) and be compacted to 95% of maximum density in accordance with AASHTO T-180. Testing of Subgrade ROADWAY DESIGN AND CONSTRUCTION STANDARDS - 6 Tests for subgrade stabilization shall be located no more than five hundred (500) feet apart and shall be located as directed by the City Engineer. Test reports for subgrade stabilization shall be submitted to the City Engineer by the Engineer of Record. When, in the judgment of the City Engineer, conditions warrant additional testing, the Engineer of Record will be advised in writing that additional tests will be required and the extent of such additional tests. (c) Materials, Proportioning, and Construction for Rigid Pavements The materials, proportioning, and construction of concrete shall be in accordance with Florida DOT Standard Specifications for Road and Bridge Construction, latest edition. (d) Equipment Forms Unless special provision is made for use of wood, all side forms for this work shall be metal

6 of a depth at least equal to the edge thickness of the pavement, except that it is permissible to increase the depth of forms by fastening boards under the forms. The section s shall have a length of at least ten (1) feet, except on curves of less than on hundred fifty (150) foot radius, where flexible steel or wood forms may be used. Forms with a height of eight (8) or more inches shall have a base width of at least eight (8) inches. Other forms shall have a minimum base width of six (6) inches. When set to grade and staked in place, the maximum deviation of the top surface of any section from a straight line shall not exceed 1/8 inch. The method of connection between sections shall be such that the joint formed shall be free from play or movement in any direction. The bracing and support must be ample to prevent the deflection of the forms under the pressure of the concrete or the weight or thrust of the machinery operating on the forms. Flexible Forms Flexible steel or wood forms may be used only when specifically provided for on the construction plans, with the exception that their use is herein approved for all curves having a radius of less than one hundred fifty (150) feet. Wood forms shall be equal in depth to the edge thickness of the pavement. Forms shall be held by stakes and securely braced at any point where necessary so that no movement will result from pressure of the concrete or the weight or thrust of machinery operating on the forms. Ready Mixed Plants The plant shall be in accordance with the Florida DOT Standard Specifications for Road and Bridge Construction, latest edition. On-Site Central Mix Plants The plant shall be in accordance with the Florida DOT Standard Specifications for Road and Bridge Construction, latest edition. The trucks used to transport the concrete shall be so constructed to prohibit segregation of the mix. ROADWAY DESIGN AND CONSTRUCTION STANDARDS DESIGN, MIXING AND PLACING FOR RIGID PAVEMENT General Concrete pavement shall be designed in accordance with AASHTO Interim Guide for Design of Pavement Structure, 1972, until such time AASHTO publishes an updated procedure for design of concrete pavement, which shall then be used. Concrete pavement shall be constructed on the prepared subgrade in accordance with these regulations and the Florida DOT Standard Specifications for Road and Bridge Construction, latest edition, and in conformity with the lines, grades, thickness, and typical cross sections shown on the construction plans. In no case shall the thickness of concrete pavement be less than: Type of Roadway Minimum Concrete Development Classification Thickness Residential Local Street 5" Collector Street 5" Industrial Local Street 6" Collector Street 8" Mixing Concrete

7 Concrete mixed in truck mixers shall be at the speed designated as mixing speed by the manufacturer for a total of 75 to 100 revolutions of the drum, unless additional water is added in conformance with the following paragraph on Transporting Concrete. Time of mixing in a central mix plant shall be a minimum of sixty (60) seconds. Transporting Concrete Concrete may be transported any distance, providing it is discharged on the grade with a slump within the required slump range and meets concrete time limit requirements. If additional water is required to maintain the specified slump of concrete transported in truck mixers, it may be added with the permission of the Engineer of Record. In this case, a minimum of twenty (2) additional revolutions of the mixer drum at mixing speed shall be required before discharging of the concrete. Concrete Time Limit The maximum length of time that the concrete can be held in the truck shall conform to the following: Air temperature 45 degrees F. to 80 degrees F. - ninety (90) minute maximum. Air temperature over 80 degrees F. with a retarder added to the mix - ninety (90) minutes maximum. Air temperature over 80 degrees F. without a retarder added to the mix - sixty (60) minutes maximum. ROADWAY DESIGN AND CONSTRUCTION STANDARDS - 8 Placing Concrete The concrete shall be deposited on the grade in such a manner as to require as little rehandling as possible. It shall be deposited in successive batches in a continuous operation. The concrete shall be consolidated by suitable means so as to preclude the formation of voids or honeycomb pockets. Placing in Cold Weather Concrete placed in cold weather shall be protected. Any concrete damaged by frost action shall be removed and replaced FINISHING FOR RIGID PAVEMENTS General The concrete shall be struck-off, consolidated, and finished with mechanical equipment in such a manner that, after final finishing, it shall conform to the pavement cross section shown on the construction plans. Hand finishing will be permitted in narrow widths, areas of irregular dimensions, and in the event of breakdown of the mechanical equipment only to finish the concrete already deposited on the grade. Final Surface Finish The final surface of the pavement shall have a uniform, skid-resistant texture. The method of texturing shall be approved by the City Engineer, and may require changes in the final finishing procedure as required to produce the desired final surface texture. A burlap drag

8 finish is recommended for residential, collector, and minor arterial streets. Major arterial and rural roads may require an overlapping stiff bristled broom or steel comb finish at the City Engineer's option. Pavement Exposed to Rain During Construction The Contractor shall always have materials available to protect the surface of the plastic concrete against rain. Areas of the pavement surface that exhibit a smooth sandy appearance after the rain ceases shall be textured and cured. An attempt shall be made to impart the specified texture to these areas before applying the membrane curing material. Areas that have suffered some surface erosion and have coarse aggregate exposed shall be re-worked by hand methods or with the finishing machine when the form paving method is used. Fresh concrete containing the same materials and properties as the pavement concrete shall be added to maintain an adequate supply in front of the screeds or machine to assure replacement of the concrete eroded from the surface. The surface shall then be textured and cured as specified. If pavement edges have been severely eroded and the concrete has not set, the edges shall be repaired by setting side forms and replacing eroded concrete. After the side forms are set, fresh concrete shall be placed and finished prior to texturing and curing. After the pavement has hardened, remedial work shall not be permitted until after the curing period has terminated. ROADWAY DESIGN AND CONSTRUCTION STANDARDS CURING FOR RIGID PAVEMENTS General After finishing operations have been completed and immediately after the free water has left the surface, the surface of the slab and, for slipformed pavements, the sides of the slab shall be coated and sealed with a uniform layer of membrane curing compound applied at the rate of not less than one (1) gallon per two hundred (200) square feet of surface. When the forms are removed, curing compound shall be applied to the sides of the slab. Areas in which the curing membrane is damaged within a period of three (3) days shall be resprayed with curing compound. Curing compound may be omitted when, in conjunction with protection of the pavement from inclement weather, a polyethylene film or other acceptable material is applied over the pavement and maintained intact for three (3) days. Cracks Concrete rigid pavement will not be accepted with excessive uncontrolled cracks. Shrinkage cracks must be avoided. Shrinkage cracks occur when evaporation exceeds the rate at which bleed water rises to the surface. Some suggestions to avoid plastic shrinkage cracks include: dampen subgrade and forms; erect wind-breaks, if doing so will reduce evaporation; erect sunshades; protect with wet coverings; reduce time between placing and start of curing; and apply light fog spray for first few hours after placing concrete. Cracks due to settlement or other structural faults must be avoided by adequate base construction JOINTS IN RIGID PAVEMENTS General

9 Transverse and longitudinal joints shall be constructed to a maximum spacing of fifteen (15) feet. Transverse joints shall extend the entire width of the pavement and through the curbs. Joints may be formed in the plastic concrete or sawed after the concrete has hardened. Formed joints may be constructed by installing a parting strip to be left in place or by depressing an approved (by the Engineer of Record) tool into the plastic concrete. Sawing of joints shall begin as soon as the concrete has hardened sufficiently to permit sawing without excessive raveling and before uncontrolled cracking occurs. Construction Joints All longitudinal joints may be construction joints, at the Engineer of Record's option. Transverse construction joints shall be installed whenever the placing of concrete is suspended a sufficient length of time for the concrete to begin to harden. Joint Sealing ROADWAY DESIGN AND CONSTRUCTION STANDARDS - 10 Joints shall be sealed before the pavement is exposed to traffic, including construction traffic. Prior to sealing, all foreign material shall be removed from the joints, and the joints shall be thoroughly dry. Joint Details Joint Details are shown in the Standard Detail section of this manual FINAL ACCEPTANCE OF RIGID PAVEMENTS General Before the pavement will be considered for acceptance, all items shall be completed in accordance with the construction plans and these Regulations. Equipment, surplus materials, and construction debris shall be removed from the project. Opening to Traffic The pavement shall be closed to traffic after the concrete is placed until it reaches a compressive strength of 2500 psi under ordinary field conditions. This does not include the sawing and sealing equipment or other light miscellaneous equipment. Testing of Concrete Concrete pavement shall have a twenty-eight (28) day compressive strength of 3000 psi. Portland cement concrete control for slump tests, air entrainment tests, beam tests, and concrete cylinder tests is required and shall be in accordance with AASHTO and ASTM Specifications, latest editions. Test reports shall be submitted to the City Engineer by the Engineer of Record for review. Before the final acceptance of the pavement, its thickness shall be determined by coring at random locations at various points on the cross section in each poured strip so that a core represents an area not exceeding two thousand five hundred (2,500) square yards, and the

10 depth of each core shall be determined by average measurements of the core in accordance with AASHTO T-148. Test reports for coring shall be submitted to the City Engineer by the Engineer of Record for review. When, in the judgment of the City Engineer, conditions warrant additional coring, the Engineer of Record will be advised in writing that additional coring will be required and the extent of such additional coring. Where the thickness of the pavement is deficient by more than ten (10) percent, it shall be removed and replaced, as directed by the City Engineer. All coring and testing will be the responsibility of the Engineer of Record, and will be in accordance with procedures and references contained herein CORNER RADII SIDEWALKS ROADWAY DESIGN AND CONSTRUCTION STANDARDS - 11 Type of Roadway Minimum Radius Development Classification Residential Local Street 25' Collector Street 35' Industrial Local Street 35' Collector Street 50' Point of Measurement Urban Sections - back of curb or gutter (parkway side). Rural Sections - edge of pavement. Sidewalks shall be constructed of Portland Cement concrete, Class I. Materials, and methods of construction, shall conform to the Florida DOT Standard Specifications for Road and Bridge Construction, latest edition. Standard thickness shall be four (4) inches, except at driveways, where the minimum thickness shall be six (6) inches ACCELERATION - DECELERATION LANES Acceleration-deceleration lanes shall be provided, if warranted, under the Florida DOT Manual of Uniform Minimum Standards for Design, Construction and Maintenance for Streets and Highways, latest edition, or as required by the City Engineer due to special conditions BRIDGES (a) Bridges shall be constructed of precast concrete, pre-stressed concrete, or cast in place concrete, unless otherwise approved by the City Engineer. (b) Bridge design shall conform to the design criteria of the AASHTO Standard Specifications for Highway Bridges, latest edition, and Florida DOT Standard Specifications for Road and Bridge Construction, latest edition. (c) The design bridge loading shall be HS One (1) set of signed,

11 sealed, and dated bridge design calculations shall be submitted by the Engineer of Record to the City Engineer. (d) Testing and reports are required and shall be in accordance with Florida DOT and AASHTO standard practices, and shall be submitted to the City Engineer by the Engineer of Record for review and approval prior to starting the next stage of construction. ROADWAY DESIGN AND CONSTRUCTION STANDARDS - 12 (e) All engineering design revisions shall be reviewed and approved by the City Engineer prior to construction ROADWAYS - URBAN SECTION Roadway Grade A minimum grade of 0.28% is required for all urban sections, but positive drainage shall be demonstrated and stormwater depths shall not exceed curb heights CONCRETE CURB, GUTTER, AND SIDEWALKS MEDIANS (a) Details of concrete curb, gutter, and sidewalks shall conform to the Standard contained herein. (b) Materials and installation shall conform to the Florida DOT Standard Specifications for Road and Bridge Construction, latest edition. Densities under curbs and gutters shall be a minimum of ninety-five (95) percent Standard Modified Proctor for a six (6) inch depth. Medians shall be curbed and conform to requirements of the DOT Standards. All bullnoses for left turn lanes shall be a minimum of four (4) inches thick concrete and shall extend the entire length of the left turn lane GRASSING AND MULCHING In residential subdivisions where home construction is not imminent, areas located within thirty (30) feet of the back of curb that are disturbed by construction shall be grassed and mulched in accordance with the Florida DOT Standard Specifications for Road and Bridge Construction, latest edition ROADWAYS Grassing and Mulching All right of way other than the roadway area shall be grassed and mulched in accordance with the Florida DOT Standard Specifications for Road and Bridge Construction, latest edition ROADWAY DITCHES

12 (A) Design Roadside ditches shall comply with the definition of a "swale" in D.E.R : (a) Its cross-section top width-to-depth ratio shall be equal to or greater than 6:1, or its side slopes shall be equal to or greater than 3:1; and ROADWAY DESIGN AND CONSTRUCTION STANDARDS - 13 (b) It can contain, or have, contiguous areas of standing or flowing water only following a rainfall event, and then only for 48 hours thereafter; and (c) It shall have, or be planted with, stabilized vegetation suitable for soil stabilization, stormwater treatment and nutrient uptake; and (d) It shall be designed for the in-site soil's erodibility, percolation, permissible velocities and drainage area so as to prevent erosion and siltation and to reduce pollutant concentration of any discharge. (B) Maximum Allowable Velocity Unless unstable or highly erosive soil conditions indicate a lower design velocity is desirable, or unless ditch paving has been provided, the maximum design velocity shall be 3.0 feet per second. (C) Minimum Roadway Ditch Grades The gradient required to provide for the design flow, or 0.10%, whichever is greater, shall be the minimum allowable grade. In all cases, data giving drainage area included, velocity and depth of flow in each ditch, together with the design storm event, shall be included in the drainage calculations. Ditch Protection The following minimum requirements shall be provided: Ditch Grade Protection Required 0.1% - 1.0% Grassing & Mulching 1.0% - 2.0% Sodding 2.0% and Greater Ditch Paving or erosion control matting Ditches shall be sodded even when the ditch grade is less than 1.0% if the design velocity is greater than 2.0 feet per second SIDEDRAIN REQUIREMENTS Permit Required The property owner shall obtain a sidedrain permit from the Engineering Division prior to home construction or to close an existing ditch. Material Specifications

13 Material specifications shall be in accordance with the Drainage Engineering section of this manual. Inverts The sidedrain pipe invert elevation shall be the same as the ditch bottom or as determined by the City Engineer. Pipe Sizes ROADWAY DESIGN AND CONSTRUCTION STANDARDS - 14 Pipe sizes shall be in accordance with the Drainage Engineering section of this manual and must be approved by the City Engineer prior to construction. Maximum Allowable Velocity Unless unstable or highly erosive soil conditions indicate a lower design velocity is desirable, or unless ditch paving has been provided, the maximum allowable outlet velocity shall be 5.0 feet per second. Mitered End Sections At each end, sidedrains shall have a mitered end section constructed in accordance with the Florida DOT Standard Index. Ditch Paving Ditch paving shall be provided at the discharge end of sidedrains. Ditch paving shall be four inches (4") thick (minimum) and shall extend across receiving ditch for a distance of ten feet (10') downstream.