334Hot-Mix Cold-Laid Asphalt Concrete Pavement

2.1 Aggregate . Furnish aggregates from sources that conform to the requirements shown in Table 1 and in

accordance with this Section. Aggregate requirements in this Section, including those shown in Table 1, may be modified, or eliminated when shown on the plans. Additional aggregate requirements may be specified when shown on the plans. Provide aggregate stockpiles that meet the definitions in this Section for coarse aggregate, intermediate aggregate, or fine aggregate. Supply aggregates that meet the definit ions in Tex-100-E for crushed gravel or crushed stone. The Engineer will designate the plant or the quarry as the sampling location. Provide samples from materials produced for the project. The Engineer will establish the Surface Aggregate Classification (SAC) and perform Los Angeles Abrasion, Magnesium Sulfate S oundness, and Micro- Deval Abrasion Tests. Perform all other aggregate quality tests shown in Table 1. Document all test results i n the mixture design report. The Engineer may perform tests on independent or split samples to verify Contractor test results. Stockpile aggregates for each source and type separately. Determine aggregate gradations for mixture design and production testing based on the washed sieve analysis in accordance with Tex-200-F , Part II.

2.1.1 Coarse Aggregate. Coarse aggregate stockpiles must have no more than 20% material passing the No. 8

sieve. Aggregates from sources listed in the Department’s Bituminous Rated Source Quality Catalog (BRSQC) are preapproved for use. Use only the rated values for hot mix listed in the BRSQC. Rated values for surface treatment (ST) do not apply to coarse aggregate sources used in hot -mix asphalt (HMA) . For sources not listed i n the Department’s BRSQC:  build an individual stockpile for each material;  request that the Department test the stockpile for specification compliance; and  once approved, do not add material to the stockpile unless otherwise approved. Provide aggregate from non- listed sources only when tested by the Engineer and approved before use. Allow 30 calendar days for the Engineer to sample, test, and report results for non- listed sources. Provide coarse aggregate with at least the minimum SAC shown on the plans. SAC requirements only apply to aggregates used on the surface of travel lanes. SAC requirements apply to aggregates used on surfaces 267 other than travel lanes when shown on the plans. The SAC for sources i n the Department’s Aggregate Quality Monitoring Program (AQMP) (Tex -499-A ) is listed in the BRSQC. 2.1.1.1. Blending Class A and Class B Aggregates. Class B aggregate meeting all other requirements shown in Table 1 may be blended with a Class A aggregate to meet requirements for Class A materials. Ensure that at least 50% by weight, or volume if required, of the material retained on the No. 4 sieve comes from th e Class A aggregate source when blending Class A and Class B aggregates to meet a Class A requirement. Blend by volume if the bulk -specific gravities of the Class A and Class B aggregates differ by more than 0.300.

2.1.2 Fine Aggregate . Fine aggregates consist of manufactured sands, screenings, and field sands. Fine

aggregate stockpiles must meet the gradation requirements shown in Table 2. Supply fine aggregates that are free of organic impurities. The Engineer may test the fine aggregate in accordance with Tex-408-A to verify the material is free of organic impurities. No more than 15% of the total aggregate may be field sand or other uncrushed fine aggregate. Use fine aggregate, except field sand, from coarse aggregate sources that meet the requirements shown in Table 1 unless otherwise approved. Test the stockpile if 10% or more of the stockpile is retained on the No. 4 sieve, and verify that it meets the requirements in Table 1 for crushed face count ( Tex-460-A ) and flat and elongated particles ( Tex-280-F ). Table 1 Aggregate Quality Requirements Property Test Method Requirement Coarse Aggregate SAC Tex-499-A (AQMP) As shown on the plans Deleterious material, %, Max Tex-217-F, Part I 1.5 Decantation, %, Max Tex-217-F, Part II 1.5 Micro -Deval abrasion, % Tex-461-A Note 1 Los Angeles abrasion, %, Max Tex-410-A 40 Magnesium sulfate soundness, 5 cycles, %, Max Tex-411-A 302 Crushed face count ,3 %, Min Tex-460-A, Part I 85 Flat and elongated particles @ 5:1, %, Max Tex-280-F 10 Fine Aggregate Linear shrinkage, %, Max Tex-107-E 3 Combined Aggregates4 Sand equivalent, %, Min Tex-203-F 45 1. Not used for acceptance purposes. Used by the Engineer as an indicator of the need for further investigation. 2. Unless otherwise shown on the plans. 3. Only applies to crushed gravel. 4. Aggregates, without mineral filler or additives, combined as used in the job -mix formula (JMF). Table 2 Gradation Requirements for Fine Aggregate Sieve Size % Passing by Weight or Volume 3/8″ 100 #8 70–100 #200 0–15

2.2 Mineral Filler . Mineral filler consists of finely divided mineral matter such as agricultural lime, crusher fines,

hydrated lime, or fly ash. Mineral filler is allowed unless otherwise shown on the plans. Use no more than 2% hydrated lime or fly ash unless otherwise shown on the plans. The plans may require or disallow specific mineral fillers. Provide mineral filler, when used, that:  is sufficiently dry, free- flowing, and free of clumps and foreign matter as determined by the Engineer;  does not exceed 3% linear shrinkage when tested in accordance with Tex -107-E ; and  meets the gradation requirements shown in Table 3. 268 Table 3 Gradation Requirements for Mineral Filler Sieve Size % Passing by Weight or Volume #8 100 #200 55–100

2.3 Baghouse Fines . Fines collected by the baghouse or other dust -collecting equipment may be reintroduced

into the mixing drum.

2.4 Binder Material . Furnish asphalt binder, primer, additives, and water, unless otherwise shown on the plans.

2.4.1 Asphalt Binder . Provide the asphalt shown on the plans, meeting the requirements of Item 300, “Asphalts,

Oils, and Emulsions.”

2.4.2 Primer. Provide an approved asphalt primer consisting of a blend of asphalt cement and hydrocarbon

volatiles.

2.4.3 Water . Provide water that meets the requirements of Item 204, “Sprinkling.”

2.4.4 Additives . Use the type and rate of additive specified when shown on the plans. Additives that facilitate

mixing or improve the quality of the mixture may be allowed when approved. Provide the Engineer with documentation, such as the bill of lading, showing the quantity of additives used o n the project unless otherwise directed. When lime or liquid antistripping agents are used, add in accordance with Item 301, “Asphalt Antistripping Agents.” Do not add lime directly into the mixing drum of any plant where lime is removed through the exhaust stream unless the plant has a baghouse or dust collection system that reintroduces the lime back into the drum.

2.5 Tack Coat . Furnish CSS -1H, SS- 1H, or a performance- graded (PG) binder with a minimum

high- temperature grade of PG 58 for tack coat in accordance with Item 300. Specialized or preferred tack coat materials may be allowed or required when shown on the plans. Do not dilute emulsified asphalts at the terminal, in the field, or at any other location before use. The Department may sample the tack coat to verify specification compliance.

4.1 Mixture Design .

4.1.1 Design Requirements. Use the typical weight design example in accordance with Tex-204-F , Part I, to

design a paving mixture consist ing of a uniform mixture of aggregate, asphalt material, primer, additives, and water, if allowed, that meets the requirements shown in Tables 4 and 5, unless otherwise shown on the plans. Ensure that the mixture leaves the plant in a workable condition. Provide materials that remain workable in a stockpile for at least 6 mo. 269 Submi t a new mixture design at any time during the project. The Engineer must approve all mixture designs before the Contractor can begin production.

4.1.2 Job-Mix Formula Approval . The job- mix formula (JMF) is the combined aggregate gradation and target

asphalt percentage used to establish target values for mixture production. JMF1 is the original laboratory mixture design used to produce the trial batch. The Engineer will verify JMF1 based on plant -produced mixture from the trial batch unless otherwise approved. The Engineer may accept an existing mixture design previously used on a Department project and may waive the trial batch to verify JMF1. Provide the Engineer with split samples of the mixtures and blank samples used to determine the ignition oven correction f actors. The Engineer will determine the aggregate and asphalt correction factors from the ignition oven in accordance with Tex-236-F . Table 4 Master Gradation Limits (% Passing by Weight or Volume) and VMA Requirements Sieve Size A Coarse Base B Fine Base C Coarse Surface D Fine Surface F Fine Mixture 2″ 100.01 – – – – 1-1/2″ 98.0–100.0 100.01 – – – 1″ 78.0–94.0 98.0–100.0 100.01 – – 3/4″ 64.0–85.0 84.0–98.0 95.0–100.0 100.01 – 1/2″ 50.0–70.0 – – 98.0–100.0 100.01 3/8″ – 60.0–80.0 70.0–85.0 85.0–100.0 98.0–100.0 #4 30.0–50.0 40.0–60.0 43.0–63.0 50.0–70.0 70.0–90.0 #8 22.0–36.0 29.0–43.0 32.0–44.0 35.0–46.0 38.0–48.0 #30 8.0–23.0 13.0–28.0 14.0–28.0 15.0–29.0 12.0–27.0 #50 3.0–19.0 6.0–20.0 7.0–21.0 7.0–20.0 6.0–19.0 #200 2.0–7.0 2.0–7.0 2.0–7.0 2.0–7.0 2.0–7.0 Design VMA ,2 % Minimum – 12.0 13.0 14.0 15.0 16.0 Production (Plant -Produced) VMA ,2 % Minimum – 11.5 12.5 13.5 14.5 15.5 1. Defined as maximum sieve size. No tolerance allowed. 2. Voids in mineral aggregates. Table 5 Laboratory Mixture Design Properties Property Test Method Requirement Target laboratory -molded density, %1 Tex-207-F 94.0 ± 1.5 Hveem stability, Min Tex-208-F 35 Cantabro loss, %, Max Tex-245-F 10 Hydrocarbon -volatile content, %, Max Tex-213-F 0.6 Moisture content, %, Max2 Tex-212-F 1.0 Boil test, %, Max3 Tex-530-C 10 1. Unless otherwise shown on the plans. 2. Unless otherwise approved. 3. Limit may be increased or eliminated when approved.

4.2 Production Operations . Perform a new trial batch when the plant or plant location is changed. Take

corrective action and obtain approval to proceed after any production suspension for noncompliance with the specification.

4.2.1 Stockpiling of Aggregates . Provide a smooth and well -drained area, cleared of trash, weeds, and grass.

Build stockpiles in a manner that will minimize aggregate degradation and segregation. Avoid contamination and mixing of stockpiles. Provide aggregate stockpiles for at least 2 days’ production before beginning plant operations. Maintain at least a 2- day aggregate supply throughout the project unless otherwise directed. Stockpile aggregate for each source and type separately. The Engineer may reject stockpiled materials that contact the earth or other objectionable material. 270 4.2.2. Storage and Heating of Asphalt Materials. Provide enough asphalt material storage capacity to meet the requirements of the plant. Do not heat the asphalt binder above the temperatures specified in Item 300, or outside the manufacturer’s recommended values. Keep all equipment used in the storage and handling of asphalt material clean at all times and operate the equipment in a manner that will prevent contamination by foreign matter.

4.2.3 Storage of the Asphalt Mi xture . Store the asphalt mixture in a surge- storage system or in a stockpile.

Provide a smooth and well -drained area, cleared of trash, weeds, and grass , if the asphalt mixture is stored in a stockpile. Build stockpiles in a manner that will minimize aggregate degradation and segregation. Avoid contamination and mixing of stockpiles.

4.2.4 Mixing and Discharge of Materials. Produce the mixture at a discharge temperature between 145°F and

275°F, as directed. Do not allow the temperature to vary from the selected temperature by more than 25°F. The Department will not pay for or allow placement of any mixture produced above 300°F.

4.2.5 Moisture Content . Furnish the mixture at a moisture content of no more than 1% by weight when

discharged from the mixer, unless otherwise shown on the plans or approved. Cease operations at moisture content above 1% until corrective actions reduce moisture content.

4.3 Hauling Operations . Clean all truck beds before use to ensure mixture is not contaminated. Use a release

agent on the Department’s MPL to coat truck beds when a release agent is necessary.

4.4 Placement Operations. Prepare the surface by removing raised pavement markers and objectionable material , such as moisture, dirt, sand, leaves, and other loose impediments , from the surface before placing

mixture. Remove vegetation from pavement edges. Place mixture on the road below 175°F. Place the mixture to produce a smooth, finished surface with a uniform appearance and texture that meet typical section requirements. Offset longitudinal joints of successive courses of mixture by at least 6 in. Place mixture so that longitudinal joints on the surface course coincide with lane lines, or as directed. Ensure that all finished surfaces will drain properly. When desired, dump the asphalt mixture in a windrow and then place in the finishing machine with windrow pickup equipment unless otherwise shown on the plans. Prevent the windrow pickup equipment from contaminating the mixture. Defer compaction after placing the paving mixture, as directed, to allow for volatilization. Allow the previous course to dry and cure before placing the next course when placing more than one pavement course. Consider the course cured if the hydrocarbon volatile content of the mixture is 0.4% or less by weight of the mixtur e when tested in accord ance with Tex -213-F , unless otherwise directed. Use a motor grader to spread the mixture when shown on the plans or approved. Thoroughly aerate the mixture and spread into place using a power motor grader in a uniform layer. Placement in narrow strips or small irregular areas may require hand- spreading.

4.4.1 Weather Conditions . Place the mixture when the roadway surface temperature is 60°F or higher , unless

otherwise approved. Place mixtures only when weather conditions and moisture conditions of the roadway surface are suitable in the opinion of the Engineer unless otherwise shown on the plans.

4.4.2 Tack Coat . Clean the surface before placing the tack coat. Apply tack coat uniformly at the approved rate

unless otherwise directed. The Engineer will set the rate between 0.04 and 0.10 gal. of residual asphalt per square yard of surface area. Apply a thin, uniform tack coat to all contact surfaces of curbs, structures, and joints. Prevent splattering of the tack coat when placed adjacent to curb, gutter, and structures. Roll the tack coat using a pneumatic tire roller when directed.

4.5 Compaction. Furnish the type, size, and number of rollers required for compaction as approved. Furnish at least one medium pneumatic tire roller (minimum 12- ton weight). Use the control strip method in accordance

with Tex-207-F , Part IV, to establish rolling patterns that achieve maximum compaction. Follow the selected rolling pattern unless changes that affect compaction occur in the mixture or placement conditions. Est ablish 271 a new rolling pattern when such changes occur. Compact the pavement to the cross -section of the finished paving mixture shown on the plans and in accordance with specifications. Operate vibratory rollers in static mode when not compacting, when changing directions, or when the plan depth of the pavement mat is less than 1- 1/2 in., unless otherwise directed. Start by first rolling the joint with the adjacent pavement and then continue by rolling longitudinally at the sides when rolling using three- wheel tandem or vibratory rollers. Proceed toward the center of the pavement, overlapping on successive trips by at least 1 ft., unless otherwise directed. Make alternat ing trips of the roller slightly different in length. Begin rolling at the low side on superelevated curves , and progress toward the high side unless otherwise directed. Avoid displacement of the mixture. Correct any displacement that may occur to the satisfaction of the Engineer. Ensure pavement is fully compacted before allowing rollers to stand on the pavement. Use only water or an approved release agent on rollers, tamps, and other compaction equipment unless otherwise directed. Keep diesel, gasoline, oil, grease, and other foreign matter off the mixture. Use tamps to thoroughly compact the edges of the pavement along curbs, headers, and similar structures , and in locations that will not allow thorough compaction by the rollers. The Engineer may require rolling using a trench roller on widened areas, in trenches, and in other limited areas . Allow the compacted pavement to cool to 160°F or lower before opening to traffic unless otherwise directed. Sprinkle the finished mat with water or limewater, when directed, to expedite opening the roadway to traffic.

4.6 Production Testing and Operational Tolerances. The aggregate gradation and the asphalt binder content of the produced mixture must not vary from the JMF by more than the percentage point tolerances shown in

Table 6. The gradation of the produced mixture may fall outside the master grading limits for any of the sieve sizes from 1 -1/2 in.–No. 50 if it is within the JMF tolerances. The aggregate gradation of the No. 200 sieve may not exceed the master gradations shown in Table 4. Any sieve size shown in Table 4 with 100% passing requirements will be allowed a 2% tolerance before the material is considered out of specification. The Engineer may allow alternate methods for determining the asphalt content and aggregate gradation if the aggregate mineralogy is such that Tex-236-F does not yield reliable results. Provide evidence to the Engineer that results from Tex-236-F are not reliable before an alternate method will be allowed. Use the applicable test procedure as directed if an alternate test method is allowed. Cease production if three consecuti ve tests indicate that the material produced exceeds the tolerances shown in Table 6 for any individual sieve or laboratory -molded density until corrective actions are taken and the results approved. Cease production if two consecutive tests indicate that the asphalt binder content tolerances shown in Table 6 are exceeded until corrective actions are taken and the results approved. Cease production if the Hveem stability shown in Table 5 is not met for three consecutive tests until corrective actions are taken and the results approved. Table 6 Operational Tolerances Property Test Method Operational Tolerance From JMF Individual % retained for sieve sizes smaller than 1 -1/2″ and larger than #8 Tex-200-F ±5.0 Individual % retained for sieve sizes smaller than #8 ±3.0 Asphalt binder content, % Tex-236-F ±0.3 Laboratory -molded density, % Tex-207-F ±1.0

4.7 Irregularities. Immediately take corrective action if surface irregularities, including segregation, rutting, raveling, flushing, fat spots, mat slippage, color, texture, roller marks, tears, gouges, streaks, or uncoated

272 aggregate particles , are detected. The Engineer may suspend production or placement operations until the problem is corrected. Remove and replace any mixture that does not bond to the existing pavement or has other surface irregularities identified above at the expense of the Contractor and to the satisfaction of the Engineer.

4.8 Ride Quality . Use Surface Test Type A to evaluate ride quality in accordance with Item 585, “Ride Quality

for Pavement Surfaces,” unless otherwise shown on the plans.