- 433 - SECTION 607 -- CONCRETE SIDEWALKS, BIKEWAYS, AND MEDIAN SURFACING
607.01 Description
1.The Contractor shall furnish all materials and construct sidewalks, curb ramps, bikeways, and median surfacing of Portland cement concrete on a prepared subgrade as described in the contract.
607.02 Material Requirements
1.The concrete Class will be specified in the contract.
2.Fill for medians shall be sand, millings, crushed concrete or other suitable material approved by the Engineer.
3.Approved detectable warning panels are shown on the Department’s Approved Products List.
4.All materials shall be furnished by the Contractor and shall conform to the requirements in Table 607.01. Table 607.01 Material Requirements Applicable Materials Section Concrete .................................................................. 1002 Fly Ash .................................................................... 1008 Aggregate ................................................................ 1033 Preformed Join t Filler .............................................. 1015 Steel Bars for Concrete Reinforcem ent ................... 1020
607.03 Construction Methods
1.Sidewalks, curb ramps, and bikeways shall be constructed as shown in the contract.
2.a. The Contractor shall pre pare the subgrade by excavating or filling to the elevation de scribed in the contract.
b.The subgrade shall be t horoughly compacted to insure stability.
c.In fills, the su bgrade shall be made at least 1 foot (300 mm) wider on each side of the required bikeway and/or sidewalk width.
d.Concrete shall be deposited upon a thoroughly moistened subgrade. Ponding or puddling shall be prohibited.
e.Sand fill, when required, shall be uniformly compacted to facilitate placing the conc rete median surfacing.
3.a. Forms shall be wood or metal and of a depth equivalent to the design thickness of concrete shown in the contract.
b.Forms shall be straight and able to support the concrete pressure without any deformation.
c.The forms shall be securely staked, braced, held firmly to the required line and grade, and sufficiently tight to prevent leakage of mortar.
d.All forms shall be thoroughly cleaned and oiled before the concrete is placed against them.
607.03 Concrete Sidewalks, Bike ways and, Median Surfacing
- 434 - e. Slip-form methods described in Subsection 603.03 may also be used.
4.a. The Contractor shall deposit concrete on the prepared subgrade so the concrete will not segregate.
b.The concrete shall be deposi ted for the full thickness of the slab in one operation and shall be consolidated. Excess concrete shall be screeded off level with the forms.
c.After consolidation, the surface shall be struck off to the required grade and cross section.
d.(1) The surface of sidewalks and medians shall be floated to produce a smooth surface free from irregularities and voids.
2.All edges and joints shall be rounded to a radius of 1/4 inch (6 mm).
3.The surface shall then be brushed to slightly roughen the surface and remove the finishing tool marks.
e.(1) Surfaces of sidewalks shall have joints marked off in square areas not less than 1.0 square yard (0.8 m2) nor more than 4.0 square yards (3.3 m2). Bikeways shall have joints marked off in squares equal their width. The joints shall be cu t at least 1/3 of the slab thickness, then edged on both sides of the cut.
2.Surfaces of median surfacing shall be jointed in accordance with the details and at the locations shown in the contract.
3.Holes for sign posts shall be formed in the median surfacing in accordance with the contract.
4.Expansion joints shall be placed as shown in the contract.
5.Detectable warning panels shall be installed on curb ramps at the locations and in accordance with the details shown in the contract.
6.After the concrete has set, the side forms shall be removed and the spaces on both sides backfilled with mo ist earth. The backfill shall be graded and then compacted level with the walk surface.
7.The Contractor shall cure t he concrete by one of the methods described for curing concrete pavement in Subsection 603.03.
607.04 Method of Measurement
1.The area of concrete sidewalks, bikeways, curb ramps, and median surfacing shall be measured in square yards (square meters).
2.Curb ramp areas shall be included in the sidewalk quantity. 3. The item “Detectable Warning Panel” shall be measured by the square foot.
607.05 Concrete Sidewalks, Bike ways and, Median Surfacing
- 435 - 607.05 -- Basis of Payment
1.P a y I t e m P a y U n i t Concrete _____ Sidewalks Square Yards (SY) [Square Meters (m2)] _____ inch Concrete _____ Bikeways Square Yards (SY) [Square Meters (m2)] Concrete _____ Median Surfacing Square Yards (SY) [Square Meters (m2)] Detectable Warning Panel Square Foot (SF) [Square Meter (m2)]
2.Sand fill, when shown in the contract, will not be measured for payment but shall be considered subsidia ry to the items of work for which direct payment is made.
3.In the event that more than one type or thickness of sidewalk or median surfacing is shown in the contrac t, an appropriate designation will be added to the pay item to differentiate the type or dimensions required.
4.Preparation of subgrade including necessary excavation and embankment for sidewalks, median su rfacing, and bikeways shall not be paid for directly but shall be considered subsidiary to the construction of the sidewalk, bikeway, or median surfacing.
5.a. The 28-day compressive stre ngth of each day's production will be determined from cyli nder strength tests.
b.Payment shall be reduced by the amount described in Table 603.03.
c.(1) If the 28-day compressive strength fails, the Contractor has the option to take 3 core samples, at no additional cost to the Department and under the supervision of the Engineer. The Department will take immediate custody of the cores at the time of sampling. The average compressive strength of these cores wi ll be used to determine the actual 28- day compressive strength of each day's production.
2.Cores shall be taken and tested within seven (7) days of being notified of the strength deficiency.
3.The Engineer will select the site where the cores will be taken.
6.Payment for the item “Detec table Warning Panel” shall be considered full compensation for all work required to furnish and install the detectable warning panels.
7.Payment is full compensation for all work described in this Section. - 436 - SECTION 608 -- CONCRETE ISLAND NOSE
608.01 Description
1.The Contractor shall prepare t he subgrade, furnish all materials, and construct concrete island noses as described in the contract.
608.02 Material Requirements
1.The concrete Class shall be specified in the contract.
2.All materials furnished by the Contractor shall conform to the requirements in Table 608.01. Table 608.01 Material Requirements Applicable Materials Section Concrete ...................................................... 1002 Preformed Join t Filler .................................. 1015 Reinforcing St eel ......................................... 1020, 1022, 1023
608.03 Construction Methods
1.Construction shall be as described in Subsection 603.03.
608.04 Method of Measurement
1.Concrete island noses cons tructed on other than new pavement slabs will be measured by the each. The concrete island noses will not be measured on new pavement.
2.Removal of pavement for the pl acement of concrete island nose will be measured in square yards (square meters).
608.05 Basis of Payment
1.P a y I t e m P a y U n i t Concrete _____ Island Nose Each (ea)
2.Removal of pavement and surfacing will be paid for in accordance with Section 203.
3.Island noses constructed on ne w pavement slabs will be subsidiary to the pavement.
4.a. The 28-day compressive stre ngth of each day's production will be determined from cyli nder strength tests.
b.Payment will be reduced by the amount described in Table 603.03.
c.(1) If the 28 day compressive strength fails, the Contractor has the option to take 3 core samples, at no additional cost to the Department, and under the supervisi on of the Engineer. The average compressive strength of these cores wi ll be used to determine the actual 28- day compressive strength of each day's production.
2.Cores shall be taken and tested within seven (7) days of being notified of the strength deficiency.
3.The Engineer will select the site where the cores will be taken.
5.Payment is full compensation for all work described in this Section.
Source: Nebraska Standard Specifications for Highway Construction, 2017 Edition. Pages 467–469 of 1,048.