Construction Overview. Section 5 Construction Considerations. Curb Ramp Construction. Curb Ramp Construction. Overview.

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1 Construction Overview Section 5 Construction Considerations Fall, 2017 Ann Johnson, PE Services Brady Rutman, SRF Consulting Group Overview Pedestrian Standard Plans Grade Breaks s Removals Curb & Gutter Detectable Warnings Finishing Roundabouts and Median Islands Driveway and Sidewalk Construction Doorway s 2 Standard Plans Legend Standard Plans S Indicates pedestrian ramp slope shall be between 5% minimum and 8.3% maximum in the direction shown and the cross slope shall not exceed 2%. S S 3 4 1

2 Standard Plans F Indicates pedestrian ramp slopes shall be greater than 2% and less than 5% in the direction shown and cross slope shall not exceed 2%. Grade Breaks: Specifications for Construction D2 Provide vertical and straight joints parallel with or at right angles to the walk centerline Align joints with joints in adjoining work when possible F S S F 5 6 Grade Breaks All grade breaks within the PAR shall be perpendicular to the path of travel ( See Notes Standard Plans sheets 1 & 2). Construction Standard Plans Sheets 1&2 To ensure initial ramps and initial landings are properly constructed, landings shall be cast separately 7 8 2

3 Construction Follow sidewalk reinforcement detail Construction: Fan Ramp: Separate with sidewalk reinforcement 9 10 Table curb if necessary. Determine controlling elevation (usually lowest elevation) and set at 7%. 7% Special Provisions Prosecution of Work (1803) 3) After the curb has been correctly poured, the Contractor has set the sidewalk forms, and prior to placing the concrete curb ramps/sidewalks, the Contractor shall verify the requirements in S-1.1B will be achieved. In addition, the longitudinalslopes shown in the Construction Plans and the Standard Plans shall be utilized unless these conditions cannot be met. The starting point for setting the forms on the controlling ramp leg should be the following: Steep (S) = 7% Flat (F) = 4% = 1.5% Sidewalk Cross Slope = 1.5% Fan ramp = 4%

4 Verify ramp length, landing dimensions, push button location, and perpendicular grade breaks. Verify landing is connected to the PAR with perpendicular grade breaks. 7% 7% Establish both landings with perpendicular grade breaks, verify second ramp is between 2% and 5%. Whenever possible set grades to work within concrete finishing tolerances. (F) (S) 2-5% (F) 4% 1% 1.4% 7% 7%

5 Use Steep and Flat slopes to help match into surrounding topography and maintain positive boulevard drainage. When placing curb, check the plan for secondary landings and adjust top of curb to match landing grades. (S) (F) (S) (F) 4 curb (S) When placing curb, check for doorways, steps, bus stops, or any other features that requires a landing at the back of curb ADA Preferred Construction Cross Slopes Ramp Gutter Flow lines Min. 0.5% Min. positive flow Max. 2.0% Max. 2% Preferred 1% Preferred 1%

6 V-Curb Note (3): Edge between new v-curb and in-place structure shall be sealed and bond breaker shall be used between existing structure and placed v-curb. Removal Limits The contractor shall use the appropriate ramp details in the plan and identify the removal limits for sidewalk and curb and gutter Removal Limits If the Contractor determines the removal limits are not adequate to meet PROWAG / MnDOTspecifications the Contractor shall stop work on that quadrant immediately and consult the Engineer. Removal Limits s required if the approaching sidewalk is inverse grade, also avoid Tenting of sidewalk

7 Removal Limits The transition panels cross slope corrections should be 1 linear Ft. of sidewalk per 0.5% per of cross slope. When PAR width is greater than 6 or over 5% running slope double the calculated transition length. Removal Limits If a secondary landing is necessary, check to see if a transition panel will also be needed to make the landing compliant. 4.5% 1.5% Example: A transition panel from in place sidewalk with 4.5% cross slope, to new sidewalk at 1.5% cross slope = 6 Linear Ft. Transition Panel (S) Removal Limits Verify removal limits will provide positive drainage as well as maintain existing drainage patterns. Removal Limits Once the Engineer and Contractor reach agreement on how to proceed the contractor may finish removals

8 Curb and Gutter Do not overlay PAR curb and gutter. New gutter face/flow line must match new road surface (See Standard Plans Sheet 3, note 7) Curb and Gutter 13% is the maximum rollover allowed Curb and Gutter Standard Plans Sheet 3, Note 3: For curb machine placements start gutter slope transitions 10 outside of all curb ramps. Curb and Gutter When constructing directional ramps, the triangular concrete piece per MnDOT Standard Plans should be poured integral with the curb and gutter (directional curb). Maintain positive flow 2-3%

9 Curb and Gutter Flow Line Profile Alterations, Mill & Overlay Projects Tabling - maintaining a cross slope of 2% or less within a crosswalk. Required when a roadway is in a stop/yield condition and flow line exceeds 2% slope (and project scope allows) Curb and Gutter Flow Line Profile Alterations, Mill & Overlay Projects Raising -elevating the curb line enough to allow compliant ramps in vertically constrained areas. Elevation Match point Curb and Gutter Bituminous patching on ADA stand-alone projects 1.0% min. 5.0% max. Curb and Gutter The contractor shall construct a contraction joint through the curb and gutter section at the bottom of the curb height transition at zero height curb (MnDOT2531)

10 Curb and Gutter: Adjustments Special Situations: Maximum Extent Feasible Curb and Gutter: Adjustments Special situations: Maximum Extent Feasible 5% Gutter Output. 5% Gutter outflow Detectable Warnings (Truncated Domes) Purpose of domes is to inform the user that they are at the edge of the roadway. Directionality only works in certain circumstances. Directionality should be done only when it works. Directional ramps are more difficult to construct with APS criteria. Detectable Warnings (Truncated Domes) Standard Plate 7038A Includes both rectangular and radial Radial detectable warnings must accommodate existing radius dimensions to nearest 5 increment

11 Detectable Warnings Detectable Warning Surface shall contrast visually with adjacent gutter, roadway, or walkway, either a light-on-dark or dark-on-light. Detectable Warnings (2531) The truncated domes shall be placed in concrete and shall be pressed firmly into the concrete to the point that concrete fills the vent holes on the truncated dome plates. Result of domes not installed correctly Detectable Warnings Good detectable edge with not so good placement. (Always check for structures in the PAR) Detectable Warnings Curb tapers are considered detectable edge when the taper starts within 3 of the edge of the truncated domes. Maintain a 2 continuous detectable edge. 3 No step through gaps

12 Detectable Warnings Recommendations from NCHRP (National Cooperative Highway Research Program) Where slip ramps T into trail: Place domes at top of ramp Where trail starts/ends at roadway: Place domes in the direction of travel Construction Finishing Spec 1503 Conformity with Contract Documents If the Contract requires a maximum or minimum dimension or value, the Contractor shall control the production and processing of the material and the performance of work so that the material or workmanship is not of borderline quality or dimension. Spec D The Engineer will use a 10 straight edge to measure the surface Construction Finishing Spec D The department considers deviations in the surface greater than 3/16 inch and deviations in formed concrete greater than ½ inch from the required location as unacceptable work. Construction Finishing Spec D The department considers deviations in the surface greater than 3/16 inch and deviations in formed concrete greater than ½ inch from the required location as unacceptable work

13 Construction Finishing Spec D Remove and replace unacceptable work as directed by the Engineer. Construction Finishing Joint Construction: Spec D2 The Contractor may form or saw the joints in walking surfaces as approved by the Engineer Driveway & Sidewalk Construction Standard Plans Sheet 1 Construction Finishing Joint Construction: Spec D If forming the joints, round joints within the walking surface with a with a ¼ inch radius edge grooving tool

14 Driveway & Sidewalk Construction Driveway & Sidewalk Construction Driveways Commercial Apron Slope: 10% Max (8% Max Preferred) Residential Apron Slope: 12% Max (8% Max Preferred) PAR Width: 4 Min (5 Preferred) Try all options to maintain 5 Driveways Maximize apron slopes when driveway match-in elevations are higher than roadway elevations 8% 1.5% 5 PAR Driveway & Sidewalk Construction Driveway & Sidewalk Construction Driveways Back of curb heights DW Curb Standard: 1 DW Curb Type 2 (Vertically Constrained): 2 DW Curb Type 3 (Vertically Constrained): 3 Doorway s Note 3) 6 Min. PAR required when adjacent to buildings. Note 4) 2/3 PAR to 1/3 Boulevard should be used when feasible. Note 7) To minimize vibration and rolling resistance, area should be free of pavers, stamped concrete, and/or excessive jointing

15 Doorway s Driveway & Sidewalk Construction Construction: Lessons Learned 2% ramp was constructed with landing lower than top of curb. 2.0% Construction: Lessons Learned Construction: Lessons Learned Curb ramp is compliant, but it fits poorly into its surroundings, and will be difficult to maintain. Slopes shown are preferred and side slopes could have been grade flush, thus eliminating V-curb. 2%-5% 2% 2% 2% 7% 2%-5%

16 Alternate Pedestrian Access Routes Alternate Pedestrian Access Routes APAR Layouts in the MN MUTCD 2014 Temporary Traffic Control Zone Layouts Field Manual