NMDOT Section 415: Pavement Surface Restoration

415.1DESCRIPTION

415.1.1 General

This Specification covers the requirements for:

1.Option A : In-Situ Cold Recycling of Existing Surfacing; and

2.Option B : Cold Milling with Hot-Mix A sphalt (HMA) or Warm Mix Asphalt (WMA)

Inlay.

Choose either option. The Contractor may change options once during the Project at no additional cost to the Department. 415.1.2 Option A: In-Situ Cold Recycling of Existing Surfacing

This Work consists of the following:

1.Pulverizing the existing surfacing;

2.Mixing an emulsified binder agent with the pulverized surfacing;

3.Mixing hot hydrated lime slurry with the pulverized surfacin g;

4.Spreading and compacting the mixture; and

5.Sealing the compacted surface.

415.1.3 Option B: Cold Mill with HMA Inlay

This Work consists of the following:

1.Cold milling;

2.Applying a tack coat; and

3.Placing an inlay of HMA or WMA.

415.2MATERIALS

415.2.1 Option A: In-Situ Cold Recycling of Existing Surfacing

The Contractor shall:

1.Use an emulsified binder age nt that is polymerized high-floa t emulsion HFE-150P,

unless otherwise specified. Changing one (1) grade up or down will change the Bid Item Unit Price based on the difference in invoice prices betwe en the grades of emulsion;

2.Change the grade only with the approval of the Project Manager and District

Laboratory supervisor;

3.Use polymerized high-float emulsion in accordance with Secti on 402, “Asphalt

Materials and Mineral Admixtures;” and

4.Use cold recycled Material that meets the following gradatio n requirements:

Table 415.2.1:1 Cold Recycled Pavement Gradation Requirements Sieve size % passing 1 1/4 inchª 100 One (1) inch 90–100 Section 415: Pavement Surface R estoration Page 195 Table 415.2.1:1 Cold Recycled Pavement Gradation Requirements Sieve size % passing ªAllow 1 1/2 inch if pavement with fabric is recycled.

The Contractor shall use sealing emulsion that is diluted high -float emulsion, CSS-1, or another approved equal.

The Contractor shall use hot hydrated lime slurry meeting the f ollowing requirements:

1.High-calcium pebble quicklime meeting the requirements of AS TM C 977;

2.Clean water in accordance with Section 509.2.6, “Water;” and

3.Slurry with a minimum dry solids content of 35% by weight an d consisting of a

uniform, pumpable suspension of solids in water. 415.2.1.1 Option A Mix Design The Contractor shall:

1.Provide a Laboratory mix design developed and tested in acco rdance with the

Department’s procedures. The mix design will establish the ini tial target addition rate for the emulsified binder agent and for the hot hydrated l ime slurry;

2.Provide copies of the Laborat ory mix design, along with supp orting documentation,

to the Project Manager, the District Laboratory supervisor, and the State Materials Bureau; and

3.Not use the mix design without State Materials Bureau approval. The Department

will consider the Laboratory mix design a starting point only. The Contractor may adjust the target addition rates for emulsified binder agent an d hot hydrated lime slurry as necessary, with the Project Manager’s approval.

415.2.2 Option B: Cold Mill with HMA Inlay Cold millings removed during the surface restoration process w ill become the property of the Department, unless used on the Project or otherwise specified. The Contractor may use cold milling Material from this P roject as RAP in the HMA or WM A inlay.

The Contractor shall:

1.Provide HMA or WMA in accordance with a Department-recognize d HMA/WMA

mixture type, with a nominal size of at least 3/4 inch or greater, and Section 423, “HOT MIX ASPHALT (HMA) (MAJOR PAVING) or Section 424, “WARM MIX APSHALT (WMA);” and

2.Use a tack coat in accordance with Section 407, “Tack Coat.” The Contractor shall

use HMA mixture containing perfo rmance-graded asphalt Material in accordance with Section 402, “Asphalt Materia ls and Mineral Admixtures.” 415.2.2.1 Option B Mix Design

The Contractor shall provide a mix design developed and approved in accordance with Section 423, “HOT MIX ASPHALT (HMA) (MAJOR PAVING or Section 42 4 , “ W A R M M I X ASPHALT (WMA).” 415.2.3 Equipment

415.2.3.1 Option A: In-Situ Cold Recycling of Existing Surfacin g Section 415: Pavement Surface R estoration Page 196 415.2.3.1.1 Cold In-Situ Machinery

The Contractor shall:

1.Use a self-propelled machine capable of pulverizing in-situ asphalt Materials to the

specified depth in one (1) pass;

2.Ensure that the machine provi des a minimum rotor cutting wid th of 12 ft with

automatic grade and slope control;

3.Use machine with screening and crushing capabilities to reduce or remove

oversized particles before mixi ng with emulsion. The Departmen t will allow the removal of a maximum of two percent (2%) oversize Material befo re adding emulsion, with the Proj ect Manager’s approval;

4.Use a mixing machine capable of mixing the pulverized Material and the emulsified

binder agent in a homogeneous mixture and placing in a windrow while preventing segregation;

5.Use a positive displacement pump capable of accurately metering the required

quantity of emulsified binder agent into the pulverized Materia l;

6.Equip the pump with a positive interlock system that will pe rmit addition of the

emulsified binder agent only when the pulverized Material is pr esent in the mixing chamber, and that will automatically shut off when the Material is not in the mixing chamber;

7.Equip each mixing machine with a meter capable of registerin g the rate of flow and

total delivery of the emulsified binder agent introduced into t he mixture; and

8.Calibrate the meter in the presence of the Project Manager b efore beginning

recycling operations and check or calibrate the meter as directed by the Project Manager.

415.2.3.1.2 Lime Slurry Equipment The Contractor shall:

1.Produce lime slurry at the job site using a batch type proce ss;

2.Ensure the Equipment accurately proportions the quicklime an d water, mixes the

two (2) to obtain proper slaking, and maintains homogeneous slu rry;

3.Provide horizontal mixing shafts in the transports used to c onvey the slurry to

maintain a homogenous mixture;

4.Add the lime slurry to the pulverized surfacing with a spray bar located at the cutting

head on the milling machine; and

5.Use a metering device that accurately measures the amount of slurry delivered to

within ± ten percent (10%) by weight.

415.2.3.1.3 Pavers The Contractor shall:

1.Place the recycled asphalt Base Course with a self-propelled asphalt paver in

accordance with Section 423.3.4.3, “Pavers,” except do not heat the screed; and

2.Use Equipment capable of spreading the recycled asphalt base in one (1)

continuous pass, without segregati on, to the section shown on t he Plans.

Section 415: Pavement Surface R estoration Page 197 When using a pick-up machine to feed the windrow into the pave r’s hopper, the Contractor shall ensure that it is capable of picking up the en tire windrow, down to the underlying Materials. 415.2.3.1.4 Rollers

The Contractor shall:

1.Provide rollers in accordance with Section 423.3.4.4, “Compa ction Equipment;”

2.Ensure that the number, weight, and types of rollers are suf ficient to obtain the

required compaction while the mixture is in a workable conditio n;

3.Use a pneumatic roller that weighs at least 30 ton for the b reakdown roller; and

4.Equip rollers with pads and water systems that prevent the r ecycled mixture from

sticking to the roller wheels. 415.2.3.1.5 Brooms

The Contractor shall maintain a working rotary power broom on site capable of removing aggregate that dislodges from the recycled surface.

415.2.3.2 Option B: Cold Mill with HMA or WMA Inlay The Contractor shall provide and use Equipment in accordance w ith Section 423, “HOT MIX ASPHALT (HMA) (MAJOR PAVING),” Section 424, “WARM MIX ASPHA LT (WMA),” Section 407, “Tack Coat,” and Section 414, “Cold Milling.”

415.3CONSTRUCTION REQUIREMENTS

Before beginning the Pre-Paving Conference, the Contractor sha ll:

1.Submit a paving schedule to t he Project Manager for pavement surface restoration

operations (Option A or Option B);

2.Begin paving operations only after the Project Manager has g iven written approval;

and

3.Monitor and record Plan depths throughout the pavement surface restoration

operations and at intervals directed by the Project Manager. T he Department will not pay for any depth in excess of the Contract-specified depth .

415.3.1 Option A: In-Situ Cold Recycling of Existing Surfacing The Contractor shall ensure that Option A Work has a minimum d epth of four (4) inches and the specified width, or as directed by the Project Manager. The Contractor shall begin placing the HMA or WMA overlay of the in-situ cold recycled layer within one (1) week of completing the in-situ cold recycled layer. The Contractor shall:

1.Remove Deleterious Materials within the width of the pavemen t to be recycled

before beginning recycling operations or other relevant Work;

2.Dispose of the debris as directed by the Project Manager;

3.Control water to the pulverized Material to facilitate unifo r m m i x i n g w i t h t h e

emulsified binder agent;

4.Add water before or with the emulsified binder agent;

Section 415: Pavement Surface R estoration Page 198 5. Provide a means to accurately meter and register the rate of flow of water into the pulverized Material;

6.Begin the initial pass of the milling Equipment at the lowes t portion of the section

and proceed in succession towards the higher side of the slope, if the typical section to be recycled is on a super elevated or sloped section;

7.Remove fillets of fine, pulve rized Material that form adjace nt to a vertical face before

spreading the recycled mix; and

8.Remove fillets adjacent to ex isting pavement if the Contract or is to remove the fillets

by overlapping during subsequent milling operation. If segregation occurs either in the windrow or behind the paver, the Project Manager may requir e the Contractor to make changes to the Equipment or operations.

If a section of recycled pavement contains a paving fabric, as identified in the Plans, the Contractor shall waste oversized Material as directed by the Pr oject Manager. This may require changes in Equipment and p rocedures to obtain an Acceptable end product.

The Contractor shall make thes e changes at no additional cost to the Department.

When a section of recycled pavement contains a paving fabric, not identified in the Plans, or if the vertical location of the fabric varies by more than o ne (1) inch from that specified, the Contractor shall submit a written proposal to the Project Manager describing in detail the recommendations for addressing the fabric. The Contractor shal l address the size of shredded fabric pieces, the remova l of oversize fabric pieces, the removal of oversize RAP, and any anticipated changes to th e emulsion addition rate.

Proposals that incorporate a reduction of the existing pavemen t thickness or a decrease in the depth of cold recycling must include an analysis addressing the structural adequacy of the proposed new pavement section. The Contractor shall submit the proposal to the State Materials Bureau for their review. The Contractor shall not be gin Work until the Project Manager approves the proposal in writing.

The Contractor shall spread the recycled asphalt base in one ( 1) continuous pass, without segregation, in accordance with the typical section.

415.3.1.1 Surface Tolerance The Contractor shall ensure that the final surface of recycled asphalt base does not deviate more than 1/4 inch w hen measured with a ten (10) ft str aightedge. 415.3.1.2 Temperature and Weather Limitations

The Contractor shall not perform recycling operations in the f ollowing conditions:

1.The average daily air temperature is below 55 °F;

2.The Chill Factor is below 35 °F;

3.The weather is foggy or rainy; or 4. The weather conditions are such that proper mixing, spreadin g, and compaction

requirements of the recycled Material cannot be accomplished. 415.3.1.3 Binder Application

Section 415: Pavement Surface R estoration Page 199 The Contractor shall apply the emulsified binder agent to the pulverized Material at the target addition rate in accordance with Section 415.2.1.1, “Option A Mix Design.” The Contractor shall maintain an allowable tolerance of ± 0.2% from the target binder content. 415.3.1.4 Lime Slurry Addition

The Contractor shall add water to the quicklime and incorporat e it uniformly into the pulverized surfacing Material at a rate that will result in 1.5 % hydrated lime by dry weight of pulverized surfacing Material. The Contractor shall control th e addition of lime slurry by continuously weighing the pulve rized surfacing Material.

415.3.1.5 Density and Rolling Requirements The Contractor shall establish a rolling pattern to obtain a m inimum of 96% of the maximum theoretical density of a Laboratory briquette, prepared in accordance with Department molding and testing procedures. The Project Manager m a y r e q u i r e a r e - demonstration of rolling capabilit ies for the following reasons :

1.The Project Manager observes a change in the recycled Materials;

2.The Contractor changes the rolling Equipment; or

3.The Contractor does not obtain proper densities.

The Contractor shall:

1.Perform initial rolling with a pneumatic roller until the mi xture has no visible

displacement;

2.Perform the final rolling, to eliminate pneumatic tire marks and achieve density, with

steel wheel rollers, either in static or vibratory mode;

3.Perform rolling in accordance with Section 423.3.5, “Placeme nt Operations;” and

4.Suspend rolling operations that result in cracking, movement , or other types of

pavement damage, and correct the problem. The Project Manager will make suspension and resumption of r olling operations decisions.

415.3.1.6 Finishing Operations The Contractor shall:

1.Not permit vehicles on the completed recycled asphalt base f or at least two (2)

hours after the recycled Material is spread and compacted;

2.Slow traffic on the recycled Material when approved by the P roject Manager;

3.Allow the recycled Material to cure so that the free moistur e in the recycled Material

reduces to a maximum of one percent (1%) above the inherent moi sture content of the existing pavement by the total weight of the mix; and

4.Determine the inherent moistur e content of the existing pavement from samples

taken at a maximum of one (1)-mile intervals, or as approved by the Project Manager.

The State will determine the free moisture content of the recy cled pavement from samples taken from the same areas and same intervals sampled fo r the inherent moisture content. The Contractor shall:

1.Take the samples and determine the free moisture immediately before sealing or

overlaying operations; Section 415: Pavement Surface R estoration Page 200 2. Seal the surface with emulsion at an approximate rate of 0.0 5 gal per square yard to 0.10 gal per square yard, in order to control surface r aveling, if the free moisture content of the recycled Materials is on percent (1%) o r less above the inherent moisture of the Material;

3.Repair unacceptable recycled Ma terial, as directed by the Pr oject Manager, before

placing a subsequents urfacing course;

4.Ensure that the surface of the recycled pavement is safe for traffic; and

5.Remove loose aggregate that dev elops on the surface of the r ecycled pavement

with a power-broom. 415.3.2 Option B: Cold Mill with HMA or WMA Inlay

The Contractor shall:

1.Ensure that Option B Work has a minimum depth of three (3) i nches, unless

otherwise specified in the Plans, and a width as specified in t he Plans, or as directed by the Project Manager;

2.Mill the pavement surface to the grades, depths, and widths specified in the Plans, if

required; and

3.Remove dirt and other objecti onable Material from the surfac e of the pavement with

blades, brooms, or other methods approved by the Project Manage r in accordance with Section 423, “HOT MIX ASPHALT (HMA) (MAJOR PAVING),” Secti on 424, “WARM MIX ASPHALT (WMA)” Section 407, “Tack Coat,” and Section 414, “Cold Milling.”

415.3.3 Contractor Quality Control 415.3.3.1 Contractor Quality Control for Materials

The Contractor shall place new HMA Materials in accordance wit h Section 423.3.6.1, “Contractor Quality Control” or WMA in accordance with Section 424.3.6.1, “Contractor Quality Control” except take random test samples from the HMA windrow b efore the Material goes through the paver. 415.3.3.2 Contractor Quality Control for Compaction See Section 423.3.6.1.2, “Contractor Quality Control for Compa ction.”

415.3.3.3 Project Verification Testing The Contractor shall place new HMA Material in accordance with Section 423.3.6.4, “Independent Assurance Testing” or WMA Material in accordance w ith Section 424.3.6.4, “Independent Assurance Testing.” 415.3.4 Department Quality Assurance 415.3.4.1 Department Quality Assurance for HMA/WMA

New HMA Materials shall meet the requirements of Section 423.3 .6.2.1, “Acceptance” and new WMA Materials shall meet the requirements of Section 42 4.3.6.2.1, “Acceptance,” with the exception that the Department will base Acceptance on random test samples taken from the HMA or WMA before the Material goes through the paver.

415.3.4.2 Department Quality Assurance Testing for HMA or WMA Compaction Section 415: Pavement Surface R estoration Page 201 The Contractor shall meet the requirements of Section 423.3.6. 2.1, “Acceptance” or Section 424.3.6.2.1, “Acceptance,” as appropriate. The Project Manager will grant an exception to the mean density requirement of at least 93% of th e theoretical maximum density if the Contractor can demonstrate that a minimum of 93% cannot be reasonably obtained because of the conditions of the ex isting Pavement Structure or Subgrade Materials. If the Project Manager grants this exemption, the Contractor shall con struct a Roadway test strip and develop a HMA or WMA compaction process to get the highest possible density based on an approved roller’s density gain per pass, in accordance with Section 423.3.4.4, “Compaction Equipment.” The Project Manager will approve the process (exce pt for the Roadway test strip) before paving operations begin. In no case shall the percentag e of theoretical maximum density exceed 98% nor fall more than three (3) percentage poin ts lower than the target density. If a lot does not meet either of these density requir ements, the Project Manager will do the following:

1.Accept and pay for the lot of HMA Material at 50% of the Bid Item Unit Price; or

2.Reject the in-place Material and require the Contractor to r emove and replace.

If the Project Manager determines that the mean measured densi ties are consistently higher, but not to exceed 93%, or lower than the current lot’s target density, the Project Manager may establish a new Acceptance lot on the Project.

415.4METHOD OF MEASUREMENT

Pavement surface restoration will be measured by the square yar d.

415.5BASIS OF PAYMENT

All Process Control and Quality Control Testing required shall be Incidental to Pavement Surface Restoration. Pay Item Pay Unit Pavement Surface Restoration Square Yard

415.5.1 Option A: In-Situ Cold Recycling of Existing Surfacing If the actual quantity of polymerized high-float emulsion varies outside the range of one percent (1%) to two percent (2% ), the Department will pay for o r credit the actual amount of variation at the invoice cost for emulsion (per ton). 415.5.2 Work Included in Payment

The development of the Contractor Quality Control Plan shall b e included in the payment and is considered incidental to the completion of this Bid Item . All references to Section 902, “Quality Control” are for reference only and no separate measur ement will be made.

Section 416: Minor Paving Page 202

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Source: New Mexico Standard Specifications for Highway and Bridge Construction, 2019 Edition. View official source ↗

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414 Cold Milling

416 Minor Paving

415Pavement Surface Restoration

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415.1DESCRIPTION

415.2MATERIALS

415.3CONSTRUCTION REQUIREMENTS

415.4METHOD OF MEASUREMENT

415.5BASIS OF PAYMENT

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