276 SECTION 306 – MILLING
306.01 Description
This work shall consist of the milling of asphalt and concrete pavements and the disposal of milled materials in accordance with 105.03. CONSTRUCTION REQUIREMENTS
306.02 General
Milling operations shall be described in the QCP in accordance with ITM 803. 10 Where the milling operation in a partial-day closure results in a longitudinal vertical or near vertical face exceeding 2 in. in height, the adjacent lane shall be milled during the same day, the milled lane resurfaced during the same day, or the vertical face tapered at a 45° angle or flatter. Where locat ed within 3 in. of a curb, surface material that cannot be removed by the cold-mil ling machine shall be removed by other approved methods. Transverse milled vertical faces greater th an 1 in. that are exposed to traffic shall be transitioned in an approved manner. 20 Castings located in milling areas that are not to be adjusted may remain in place during the milling or may be removed a nd replaced at the C ontractor’s option. Localized weak areas uncovered by the milling process shall be patched in accordance with 304 or 305. The milled material shall become the property of the Contractor, unless otherwise specified. The roadway shall be cleaned before opening to traffic. 30
306.03 Equipment
Equipment for milling shall be in accordance with the following.
a.Roadway Milling Machine A milling machine shall be a power operated cold-milling machine, equipped with automatic control devices to establish profile grades by referencing from either the existing pavement or from independent grad e control. The equipment shall have a positive means of controlling cross slope elevations, have an effective means for removing excess material from the surface, preventing airborne dust escaping from the 40 operation, and producing a finished surface that provides a good bond to the new overlay. Sufficient cutting teeth shall be on the coarse milling or fine milling cutting drum to produce cuttings such that 90% of the conglomerate particles pass a 2 in. sieve. A coarse milling cutting drum shall have 5/8 in. spacing between the cutting teeth and 306.01 277 be capable of producing a surface macrotex ture ratio in acco rdance with ITM 812 equal to or greater than 1.8. A fine milling cutting drum shall have 5/16 in. or 3/8 in. spacing between the cutting teeth and be capable of producing a surface macrotexture ratio in accordance with ITM 812 equal to or greater than 5.0. 50
b.Power Saw Sawing equipment shall be capable of maintaining the specified alignment and depth of cut without damaging the pavement.
c.Rotary Power Broom A motorized, pneumatic tired unit with rotary bristle broom head.
d.Straightedge 60
1.Straightedge – 16 ft The straightedge shall be a walk behind, rigid beam device on two solid wheels on axles 16 ft apart with adjustable rods at the 1/4, 1/2, and 3/4 points. The adjustable rods shall be set to a 1/4 in clearance from the bottom of the rods to the bottom of the wheels when checked with a taut stringline running from wheel to wheel at each end of the straightedge. The straightedge shall be operated in the wheel path approximately 3 ft transversely from the edge line in the direction of traffic and parallel to the pavement centerline. The operator of the straightedge shall walk the equipment over the completed pavement surface while maintaining the alignment of the equipment in the presence of the Engineer. 70
2.Straightedge – 10 ft A 10 ft straightedge is the same as a 16 ft straightedge except that the wheels are mounted 10 ft apart. A handheld rigid beam may be substituted.
306.04 Asphalt or PCCP Scarification Milling
Scarification milling shall consist of preparing a base for resurfacing by roughening the entire existing asphalt or PCCP surface. The milled pavement profile shall have a surface finish that does not vary longitudinally more than 1/4 in. from a 16 ft straightedge or as described in the QCP in accordance with 401.02. 80 A fine milling cutting drum in accordance with 306.03(a) shall be used when a single course overlay is specified with a lay rate as shown on the plans less than 165 lb/sq yd and the maximum scarification mill cut depth is expected to be less than 3/4 in. for asphalt or PCCP, otherwise, a coarse milling cutting drum in accordance with 306.03(a) shall be used. The scarified milled surface shall have a macrotexture ratio in accordance with ITM 812 as follows:
a.equal to or greater than 5.0 when using a fine milling cutting drum for a single course overlay, or 306.04
b.equal to or greater than 2.2 for a single course overlay, or
c.equal to or greater than 1.8 for multiple course overlays. Frequency of macrotexture testing shall be a minimum of once per day and shall be described in the QCP. The cross slope shall not vary more than 1/8 in. when measured with a 10 ft straightedge. 100 Milled traveled way areas left open to traffic for longer than five work days will be assessed $1,600.00 per day per lane mile, or portion thereof, as liquidated damages, not as a penalty, but as damages sustained for each work day that the milled area remains open to traffic. Milled non-traveled way areas such as a uxiliary lanes and shoul ders left open to traffic for longer than 10 work days will be assessed $800.00 per day per lane mile, or portion thereof, as liquidated damages, not as a penalty, but as damages sustained for each work day that the milled area remains open to traffic. 110
306.05 Asphalt or PCCP Profile Milling to Correct Cross Slope
Profile milling shall consist of preparing a base for resurfacing by removing the existing asphalt or PCCP material to the specified cross slope as shown on the plans. The milled pavement profile shall have a surface finish that does not vary longitudinally more than 1/4 in. from a 16 ft straightedge or as described in the QCP in accordance with 401.02. A fine milling cutting drum in accordance with 306.03(a) shall be used when a single course overlay is specified with a lay rate as shown on the plans less than 165 120 lb/sq yd and the maximum profile mill cut depth is expected to be less than or equal to 1 1/2 in. for asphalt or 3/4 in. for PCCP, otherwise, a coarse milling cutting drum in accordance with 306.03(a) shall be used. The profile milled surface shall have a macrotexture ratio in accordance with ITM 812 as follows: (a) equal to or greater than 5.0 when using a fine milling cutting drum for a single course overlay, or
b.equal to or greater than 2.2 for a single course overlay, or
c.equal to or greater than 1.8 for multiple course overlays. Frequency of macrotexture testing shall be a minimum of once per day and shall be described in the QCP. The cross slope shall not vary more than 1/8 in. when measured with a 10 ft straightedge. 306.05 279 Milled traveled way areas left open to traffic for longer than five work days will be assessed $1,600.00 per day per lane mile, or portion thereof, as liquidated damages, 140 not as a penalty, but as damages sustaine d for each work day that the milled area remains open to traffic. Milled non-traveled way areas such as auxiliary lanes and shoulders left open to traffic for longer than 10 work days will be assessed $800.00 per day per lane mile, or portion thereof, as liquidated damages, not as a penalty, but as damages sustained for each work day that the milled area remains open to traffic.
306.06 Approach Milling Approach milling shall consist of milling the surface and cutting a wedge at the 150
driveways, commercial or public road a pproaches. The existing approach shall be milled a minimum depth of no less than 1/4 in. to accommodate the approach pavement. The approach milling shall be completed to provide a smooth transition from the traveled way pavement to the termini of the approach. The existing approach pavement shall be cut to provide a vertical face of 1 1/2 in. for the termini of surface. Mailbox approaches to be resurfaced shall be milled to maintain the traveled way profile and cross slope. Automatic control devices will not be required on surface milling equipment used 160 for approach milling. Milling shall not damage any pavement that is to remain in place. Approach milling shall not be performed at driveways unless it is required to meet a paved surface that continues beyond the cons truction limit. If the driveway is other than HMA or PCC beyond the construction limits , the approach milling is not required. The transverse vertical cut face for commercial or public road approaches shall be transitioned at a rate of 24:1 or as directed.
306.07 Asphalt or PCCP Milling to a Specified Average Depth 170
Milling shall consist of preparing a base for resurfacing by removing the existing asphalt material or PCCP to the specified average depth as shown on the plans. The milled pavement shall have a surface finish that does not vary longitudinally more than 1/4 in. from a 16 ft straightedge or as de scribed in the QCP in accordance with 401.02. A fine milling cutting drum in accordance with 306.03(a) shall be used when a single course overlay is specified with a lay rate as shown on the plans less than 165 lb/sq yd and the average mill cut depth is less than or equal to 1 1/2 in. for asphalt or 3/4 in. for PCCP, otherwise, a coarse milling cutting drum in accordance with 306.03(a) shall be used. 180 The milled surface shall have a macrotexture ratio in accordance with ITM 812 as follows: 306.07 280 (a) equal to or greater than 5.0 when using a fine milling cutting drum for a single course overlay, or
b.equal to or greater than 2.2 for a single course overlay, or
c.equal to or greater than 1.8 for multiple course overlays. 190 Frequency of macrotexture testing shall be a minimum of once per day and shall be described in the QCP. The cross slope shall not vary more than 1/8 in. when measured with a 10 ft straightedge. If shoulders or turn lanes are not milled and the overlay material is not placed in the milled areas within the same day, drainage slots shall be provided to eliminate ponding of water. Milled traveled way areas left open to traffic for longer than five work days will 200 be assessed $1,600.00 per day per lane mile, or portion thereof, as liquidated damages, not as a penalty, but as damages sustained for each work day that the milled area remains open to traffic. Milled non-traveled way areas such as a uxiliary lanes and shoul ders left open to traffic for longer than 10 work days will be assessed $800.00 per day per lane mile, or portion thereof, as liquidated damages, not as a penalty, but as damages sustained for each work day that the milled area remains open to traffic. The transverse vertical cut face shall be transitioned by HMA or prefabricated 210 materials at a rate of 24:1 or as directed. 306.08 Asphalt Overlay Removal Asphalt removal shall consist of complete removal of an asphalt overlay by milling from a portland cement concrete or brick base and the satisfactory disposal of the milled materials. Minor amounts of asphalt pavement material bonded to a concrete base at joints or cracks may remain in place. If this material becomes displaced during subsequent operations, it sh all be removed. Minor amounts of asphalt pavement material bonded to a brick base may remain in place. Removal of minor areas of portland cement concrete or brick base during the milling operations is 220 acceptable. Milled areas shall be cleaned prior to reopening to traffic or before continuing construction operations. The transverse vertical cut face shall be transitioned by HMA or prefabricated materials at a rate of 24:1 or as directed.
306.09 Transition Milling Transition milling shall consist of cutting a wedge at the beginning and ending of 230 306.08
281 projects, and paving exceptions. The existing pavement shall be cut to provide a nearly vertical face of 1 1/2 in. or the minimum finished thickness of a course in accordance with 401.14, whichever is greater, for the termini of each overlay lift of base, intermediate, and surface. The existing pavement shall be milled at a rate of 720:1 or as directed to achieve the specified cut where the pavement transition overlay lifts differ from cut depth. The transverse vertical cut face shall be transitioned by HMA or prefabricated materials at a rate of 24:1 or as directed. Automatic control devices will not be required on surface milling equipment used for transitions cut off the traveled way. Cutting shall not damage any pavement that is to remain in place.
306.10 Method of Measurement
Approach milling, asphalt milling, asphalt removal, PCCP milling, scarification milling, profile milling, and transition milling will be measured by the square yard of the milled area. 306.11 Basis of Payment 250 Approach milling, asphalt milling, asphalt removal, PCCP milling, scarification milling, profile milling, and transition milling will be paid for at the contract unit price per square yard. Payment will be made under: Pay Item Pay Unit Symbol Milling, Approach ..................................................................... SYS Milling, Asphalt, ________ in. .................................................. SYS 260 thickness Milling, Aspha lt Removal ......................................................... SYS Milling, PCCP ________ in. ..................................................... SYS thickness Milling, Pr ofile .......................................................................... SYS Milling, Scarification ................................................................. SYS Milling, Transition ..................................................................... SYS The cost for castings removed and replaced at the Contractor’s option in accordance with 306.02 shall be included in the cost of the milling. 270 Any portion of the pavement that is damaged or removed outside the milling limits shall be replaced with no additional payment. The cost of tapering of vertical faces and removal of milled material from the project site shall be included in the cost of milling. 306.11 282 The cost of cutting of the surface c ourse shall be included in the milling. Furnishing and operating the 16 ft straight edge shall be included in the cost of 280 other pay items within this section.
Source: Indiana Standard Specifications, 2024 Edition. Pages 5–11 of 1,248.