411.01 Description
This work is the removal of existing bituminous pavement at the locations and depth specified in the contract or designated by the Project Manager.
411.02 Reserved
411.03 Construction Requirements
411.03.1 Equipment
Use a power-operated cold milling machine equipped to control cross slope and to establish profile grade from the existing pavement or an external reference.
411.03.2 General
Do not start cold milling until the surfacing plant is fully operational and a mix design has been submitted and approved. Starting at the center of the road, begin milling on a longitudinal line parallel to the centerline with succeeding passes progressing to the outer edge of the pavement, unless approved by the Project Manager. Remove all thin delaminated or loose layers of existing pavement left after cold milling. Replace the milled pavement at bridge ends and cattle guards with new bituminous surfacing the same day leaving no transverse joints in the milled areas. If new surfacing cannot be placed on the milled area the same day, transition at no less than a 50H:1V to the original surface. The completed milled surface is to be free from transverse and longitudinal irregularities exceeding ¼-inch (6 mm) when measured with a 10-foot (3 m) straightedge. Each successive pass will be pulled even with the previous and not staggered. After cold milling, do not leave the remaining pavement exposed to traffic more than 72 hours before placing the plant mix surfacing. The 72-hour duration may be modified by the project manager depending on the durability of the milled surface. The Contractor will be responsible for repairing any damage that occurs to the roadway prior to plant mix paving. Do not proceed with paving without the approval of the Project Manager. Replacing existing pavement is a separate operation from any succeeding overlay or lift.
411.03.3 Milling
A.Connections. Mill the existing bituminous surfacing from bridge decks, bridge approaches, cattle guards, and project connections at the locations specified in the contract or as directed by the Project Manager.
1.Bridge Decks. • Mill the depth shown in the contract or as adjusted to meet field conditions.
2.Bridge Ends. • Mill full depth from the bridge end out for a distance of 30 feet (10 m) prior to the milling taper. • For milling depths less than or equal to 0.35 feet (105 mm), mill a taper distance of 200 feet (60 m). • For milling depths greater than 0.35 feet (105 mm), mill a taper distance based on a rate of 30 feet per 0.05 feet (10 m per 15 mm) of milling depth. 411 – COLD MILLING 2020 EDITION V5.1 411-2
3.Cattle Guards or Railroad Crossings. • Mill full depth from the cattle guard or railroad crossing out for a distance of 15 feet (5 m) prior to the milling taper. • Mill a taper distance of 50 feet (15 m).
4.Project Connections. • For milling depths less than or equal to 0.35 feet (105 mm), mill a taper distance of 200 feet (60 m). • For milling depths greater than 0.35 feet (105 mm), mill a taper distance based on a rate of 30 feet per 0.05 feet (10 m per 15 mm) of milling depth.
B.Milling at Other Designated Areas. Mill the existing pavement at the locations, widths and depths specified. The depth is measured below the existing pavement plane projected from points on un-distorted pavement near the centerline and the edge of the driving lane.
C.Cold Milling for Seal and Cover. Meet the following requirements when a seal and cover is placed directly on the cold mill surface:
1.Use a cold milling cutting head having maximum ¼-inch (6 mm) tooth spacing.
2.Equip the milling machine with automatic controls and sensors on both sides to maintain the specified grade and transverse slope.
3.Do not operate the milling machine in excess of 75 feet/minute (23 m/minute) unless it can be demonstrated to the Project Manager that the milled surface can meet the plant mix overlay surface tolerance specified in accordance with Subsection
401.03 23(B)
.
4.Do not begin placing the seal and cover until all cold millwork is complete.
411.03.4 Salvage of Pavement Millings
Milled pavement is the Contractor’s property and must be removed from the project unless used for traffic gravel and/or shoulder gravel. When required by the contract salvage, haul, and stockpile the milled pavement to the specified site.
411.03.5 Replacing Removed Pavement
Pave all milled areas in the contract with the specified bituminous mixture, placed to the specified depth. Grades will be provided at 50-foot (15 m) intervals for placing the new pavement for 250 feet (75 m) from each bridge end and 100 feet (30 m) from cattle guards. Set a wire line for grade control with intermediate supports to prevent wire deflection exceeding 3⁄16-inch (5 mm). Stop paving if the deflection exceeds 3⁄16-inch (5 mm) and make appropriate corrections. Apply a tack coat on all milled areas before paving.
411.03.6 Traffic Control
Furnish traffic control in accordance with Section 618.
411.04 Method of Measurement
Cold milling is measured by the square yard (m2) of pavement removed to the specified depth.
411.05 Basis of Payment
Payment for the completed and accepted quantities is made under the following: Pay Item Pay Unit 2020 EDITION V5.1 COLD MILLING - 411 411-3 Cold Milling Square Yard (m2) The contract unit price may be adjusted if the Project Manager issues a written order to increase or decrease the milling depth. Hauling, windrowing, transferring, or stockpiling cold milled material will not be measured for payment. Include all costs for the disposal of cold millings in the unit bid price for Cold Milling.
Referenced in this section
Sections that cite this one
Cold Milling in other states
Get an email when 411 changes
Montana revises spec sections through supplementals and new editions. We check this one every week and email you the day it changes. Free, no account.
Source: Standard Specifications for Road and Bridge Construction, 2020 (v5.1) Edition. Pages 271–274 of 611. View official source ↗