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Trang 1NATIONAL STANDARD
TCVN 8819:2011
First edition
SPECIFICATION FOR CONSTRUCTION OF HOT MIX ASPHALT CONCRETE
PAVEMENT AND ACCEPTANCE
HANOI – 2011
Trang 2Table of Contents
1 Scope of application 4
2 References 4
3 Terminology and Definition 5
4 Classification and technical criteria for asphalt concrete 6
5 Requirement on quality of asphalt concrete materials 8
6 Asphalt concrete mix design 9
7 Asphalt concrete mix production at batching plant 10
8 Asphalt concrete construction 11
9 Supervision, Inspection and Acceptance of Asphalt Concrete layer 16
10 Labor safety and environmental protection 19
Trang 3TCVN 8819:2011 is converted from 22 TCN 249-98 according to regulations in Clause 1, Article 69,
Law on Technical Standards and Regulations and point a, section 1, clause 1, Article 7, DecreeNo.127/2007/ND-CP dated 01/08/2008 by the Government providing details for implementation of somearticles under Law on Technical Standards and Regulations
TCVN 8819:2011 is composed by Institute of Transport Science and Technology, recommended by
Ministry of Transport, verified by Directorate for Standards, Metrology and Quality and published byMinistry of Science and Technology
Trang 41.2 This standard is applied for new construction, repair, and improvement of pavement for highway,street, road, yard and square.
1.3 This standard is in no case applied for asphalt concrete using bitumen with improvementadmixture, mastic asphalt, asphalt concrete with special function (thin asphalt concrete layer with highroughness, porous asphalt with high roughness, stone matrix asphalt)
2 References
The following references are very necessary for applying this standard For references with year ofpublish indicated, apply the stated version For references without specifying date of issuance, apply thelatest version including modifications (if any)
TCVN 7572-2: 2006 Aggregates for concrete and mortar – Testing method – Part 2: Determination ofparticle size distribution
TCVN 7572-7: 2006 Aggregates for concrete and mortar – Testing method – Part 7: Determination ofmoisture
TCVN 7572-8: 2006 Aggregates for concrete and mortar – Testing method – Part 8: Determination ofcontent of dust, mud, clay in aggregates and clay lumps in fine aggregate
TCVN 7572-10: 2006 Aggregates for concrete and mortar - Testing method – Part 10: Determination ofstrength and softening coefficient of the original stone
TCVN 7572-11: 2006 Aggregates for concrete and mortar - Testing method – Part 11: Determination ofcrushing value and softening coefficient of coarse aggregate
TCVN 7572-12: 2006 Aggregates for concrete and mortar - Testing method – Part 12: Determination ofresistance to degradation of coarse aggregate by abrasion and impact in Los Angeles machine
TCVN 7572-13: 2006 Aggregates for concrete and mortar - Testing method – Part 13: Determination ofelongation and flakiness index of coarse aggregate
TCVN 7572-17: 2006 Aggregates for concrete and mortar - Testing method – Part 17: Determination offeeble weathered particle content
TCVN 7572-18: 2006 Aggregates for concrete and mortar - Testing method – Part 18: Determination ofcrushed particle content
TCVN 4197-1995 Soil – Laboratory method for determination of plastic limit and liquid limit
TCVN 7493:2005 Bitumen – Technical Specification
TCVN 7494:2005 Bitumen – Sampling method
TCVN 7495:2005 Bitumen – Method for determination of penetration
TCVN 7496:2005 Bitumen – Method for determination of elongation
TCVN 7497:2005 Bitumen – Method for determination of softening point (ring and ball apparatus)TCVN 7498:2005 Bitumen – Test Method for Flash and Fire Points by Cleveland Open Cup Tester.TCVN 7499: 2005 Bitumen - Test Method for Weight Loss on Heating
TCVN 7500: 2005 Bitumen - Test Method for Solubility in Trichloroethylene
TCVN 7501: 2005 Bitumen - Test Method for Specific weight (Pycnomefer method)
TCVN 7503: 2005 Bitumen - Determination of the Paraffin Wax Content by Distillation
TCVN 7504: 2005 Bitumen – Test method for adhesion with paving stone
TCVN 8860-1:2011 Asphalt concrete – Test method – Part 1: Determination of Marshal stability andMarshal flow
TCVN 8860-4:2011 Asphalt concrete – Test method – Part 4: Determination of Maximum SpecificGravity and Density of loose Bituminous Paving Mixtures
TCVN 8860-5:2011 Asphalt concrete – Test method – Part 5: Determination of Bulk Specific Gravityand Unit Weight of Compacted Bituminous Mixtures
Trang 5TCVN 8860-7:2011 Asphalt concrete – Test method – Part 7: Determination of Fine AggregateAngularity
TCVN 8860-8:2011 Asphalt concrete – Test method – Part 8:Determination of Compaction CoefficientTCVN 8860-9:2011 Asphalt concrete – Test method – Part 9: Determination of Air Voids
TCVN 8860-10:2011 Asphalt concrete – Test method – Part 10: Determination of Voids in the MineralAggregates
TCVN 8860-12:2011 Asphalt concrete – Test method – Part 12: Determination of Remaining Stability ofasphalt concrete
TCVN 8820:2011 Hot mix asphalt concrete – Designed by Marshall method
TCVN 8864:2011 Highway pavement - Standard test method for measuring road pavement surfaceroughness using a 3.0m straight edge
TCVN 8865:2011 Highway pavement - Method for measuring and assessment roughness by
International Roughness Index (IRI).
TCVN 8866:2011 Highway pavement – Standard test method for measuring pavement macrotexturedepth using a volumetric technique
TCVN 8817-1:2011 Cationic emulsified asphalt – Part 1 – Technical Specification
TCVN 8818-1:2011 Cut-back asphalt – Part 1 – Technical Specification
AASHTO T 176 Standard Method of Test for Plastic Fines in Graded Aggregates and Soils by Use of theSand Equivalent Test
AASHTO T 324-04 Standard Method of Test for Hamburg Wheel-Track Testing of Compacted Hot MixAsphalt (HMA)
3 Terminology and Definition
In this standard the following terms are used:
3.1 Hot Mix Asphalt Concrete Pavement
The pavement (including 1 or more layers with designed thickness) produced from hot mixing asphaltconcrete
3.2 Hot Mix Asphalt Concrete - HMA
A mix constituted of aggregates (crushed stone, sand, mineral powder) with a pre-designed mixingproportion, and then being heated and mixed, mixed with a certain rate of asphalt by mixing design Hotmix asphalt is produced in the batching plant
3.3 Maximum Size of Aggregate
The minimum size of sieve that percentage of particle passing that size is 100%
This standard uses ASTM square sieve mesh system to test aggregate particle size and shows aggregatecurve by size of aggregate particle
3.4 Nominal Maximum Size of Aggregate
The largest sieve that retains some of the aggregate particles but generally not more than 10 percent byweight
3.5 Asphalt Content
The amount of asphalt in asphalt concrete mixture, by percentage of asphalt concrete mix weight(including aggregates of crushed stone, sand, mineral powder, asphalt)
3.6 Optimum Asphalt Content
Content of asphalt to be determined by asphalt concrete design, in proportion with a selected percentage
of aggregates and satisfies all technical specifications for aggregates and asphalt concrete indicatedherein
3.7 Air voids
Trang 6Total volume of all small airspaces or pockets of air that occur between the coated aggregates in thecompacted mixture of asphalt concrete Air voids are shown by volumetric percentage of compactedasphalt concrete mixture sample.
3.8 Voids in the Mineral Aggregate
The intergranular space occupied by asphalt and air in a compacted asphalt mixture It is the sum ofvolume of air and the volume of effective asphalt Voids in the mineral aggregate is indicated byvolumetric percentage of compacted asphalt concrete mixture sample
4 Classification and technical criteria for asphalt concrete
4.1 Classification of asphalt concrete
4.1.1 By air void, asphalt concrete is classified into 2 types:
- Dense-graded Asphalt Concrete (DAGC): with aid void ranging from 3% to 6%, used aspavement surface and sub-surface course The mixture must compose of mineral powder;
- Open-graded Asphalt Concrete (OGAC): With aid void ranging from 7% to 12% and use as basecourse
4.1.2 By nominal maximum size of aggregate of dense - graded asphalt concrete, it is classified into 4types:
- Dense - graded asphalt concrete with nominal maximum size of aggregate of 9.5mm (andmaximum size of aggregate is 12.5mm), shortly called DAGC 9.5;
- Dense - graded asphalt concrete with nominal maximum size of aggregate of 12.5mm (andmaximum size of aggregate is 19mm), shortly called DAGC 12.5;
- Dense - graded asphalt concrete with nominal maximum size of aggregate of 19mm (andmaximum size of aggregate is 25mm), shortly called DAGC 19;
- Dense - graded asphalt concrete with nominal maximum size of aggregate of 4.75mm (andmaximum size of aggregate is 9.5mm), shortly called DAGC 4.75;
Limit on composition of aggregate mixture (tested following TCVN 7572-2:2006) and scope ofapplication of types of DAGC are stated in Table 1
Table 1 – Proportion of Aggregate of dense-graded asphalt concrete (DAGC) mixture
Specification DAGC 9.5 DAGC 12.5 DAGC 19 DAGC 4.75
1 Nominal maximum size of aggregate, mm 9.5 12.5 19 4.75
2 Size of square sieve mesh, mm Passing sieve, % weight
3 Recommended asphalt content % weight of
asphalt concrete mixture 5.2÷6.2 5.0÷6.0 4.8÷5.8 6.0÷7.5
4 Reasonable thickness of asphalt concrete
layer (after compaction) cm 4÷5 5÷7 6÷8 3÷5
5 Scope of application Surface courseSurface and sub-surface course Sub-surfacecourse
Sidewalk, lane for bicycle and non-motorized vehicles4.1.3 By nominal maximum size of aggregate of Open - graded asphalt concrete, it is classified into 3types:
Trang 7- Open - graded asphalt concrete with nominal maximum size of aggregate of 19mm (andmaximum size of aggregate is 25mm), shortly called OGAC 19;
- Open - graded asphalt concrete with nominal maximum size of aggregate of 25mm (andmaximum size of aggregate is 31.5mm), shortly called OGAC 25;
- Open - graded asphalt concrete with nominal maximum size of aggregate of 37.5mm (andmaximum size of aggregate is 50mm), shortly called OGAC 37.5;
Limit on composition of aggregate mixture (tested following TCVN 7572-2:2006) and scope ofapplication of types of OGAC are stated in Table 2
Table 1 – Proportion of Aggregate of Open-graded asphalt concrete (OGAC) mixture
Specification OGAC 19 OGAC 25 OGAC 37,5
1 Nominal maximum size of aggregate, mm 19 25 37,5
2 Size of square sieve mesh, mm Passing sieve, % weight
-3 Recommended asphalt content % weight of
asphalt concrete mixture 4.0÷5.0 3.5÷4.5 3.0÷4.0
4 Reasonable thickness of asphalt concrete
layer (after compaction) cm 8÷10 10÷12 12÷16
5 Scope of application Base course Foundation Foundation
4.2 Proportion for mixture aggregate for DAGC and OGAC while designing must be in limit specified inTable 1 and Table 2 The grading curve of designed aggregates must be regular, do not change fromlower limit of a sieve size to upper limit of the next size and vice versa
4.3 Optimum asphalt content of DAGC and OGAC (calculated by % of weight of asphalt concretemixture) is selected based on mix design by Marshall method, so that technical criteria of designedasphalt concrete sample satisfy technical specifications in Table 3 for DAGC and Table 4 for OGAC.Sequence of asphalt concrete mix design by Marshall method follows guidance in TCVN 8820:2011 andAppendix A
Table 3- Technical specifications for dense graded asphalt concrete (DAGC)
Indicators
Specification
Test method
DAGC 19 DAGC 12.5 DAGC 9.5 DAGC 4.75
- Maximum nominal particle size 9.5mm
- Maximum nominal particle size 12.5mm
≥ 15
≥14
≥13
≥17 TCVN 8860-10:2011
Trang 8- Maximum nominal particle size 19mm
7 Depth of wheel tracking (HWTD – Hamburg Wheel Tracking
Device), 10000 circles, pressure of 0.70MPa, temperature of
AASHTO T 324-04
(*): Test only with special instruction by the Employer, It is possible to compact for sampling with modified Marshall method (TCVN 8860-1:2011)
Table 4: Technical specifications on open graded asphalt concrete (OGAC)
Indicators OGAC 19, OGAC 25 Specification OGAC 37.5 (*) Test method
(*): Test in accordance with the enhanced Marshall method.
(**) : Immersing time of sample: 60 minutes.
5 Requirement on quality of asphalt concrete materials
Table 5 - Physico-mechanical indicators for crushed stone
Indicator Regulation Test method
DGAC ODAC Top course Bottom course Base course
1 Compressive strength of source rock,
2 Loss due to strike inside Los Angeles
7 General content of dust, mud, clay, % ≤2 ≤2 ≤2 TCVN 7572- 8 : 2006
8 Ball clay content, % ≤ 0.25 ≤ 0.25 ≤ 0.25 TCVN 7572- 8 : 2006
9 Cohesion of gravel and asphalt (**),
grade
≥ grade 3 ≥ grade 3 ≥ grade 3 TCVN 7504 : 2005 (*): Use square mesh sieve with dimension ≥ 4.75 mm, regulated at Table 1, Table 2 to Content of flakiness and elongation particle
(**): Where the crushed stone source intended for asphalt concrete production has the cohesion with asphalt less than grade 3, it
is necessary to consider solutions: use admixture for adhesive strength increase (cement, lime, chemical additives), or use crushed stone from other sources to ensure the adhesive strength The solution shall be decided by Supervision Consultant.5.2 Sand
5.2.1 Sand used to make asphalt concrete is natural sand, milled sand, or a mixture of natural sand andmilled sand
5.2.2 Natural sand shall not contain organic impurities (wood, coal )
5.2.3 Milled sand shall be from rock whose compressive strength is not less than the compressivestrength of those used to produce crushed stone
Trang 95.2.4 Sand used for sand asphalt (DGAC 4.75) shall contain a content not less than 18% for those withsieve number ranging from 4.75 mm to 1.18 mm.
5.2.5 Physico-mechanical indicators of sand should meet requirements specified in Table 6
Table 6 - Physico-mechanical indicators for sand
Indicator Regulation Test method
3 General content of dust, mud, clay, % ≤ 3 TCVN 7572- 8 : 2006
4 Content of ball clay, % ≤ 0,5 TCVN 7572- 8 : 2006
5 Lobbing loam of sand (void of sand before compression), %
- DGAC of top course
- DGAC of bottom course ≥43
5.3.3 Mineral powder must be dry, not clotting
5.3.4 Physico-mechanical indicators of mineral powder should meet requirements specified in Table 7
Table 7 - Physico-mechanical indicators for mineral powder
1 Particle content (passing through square –hole
5.4.2 Asphalt 60/70 is very suitable for producing types of DGAC and ODAC Asphalt 85/100 is verysuitable for producing DGAC 4.75
6 Asphalt concrete mix design
6.1 The aim of the mix design is to find out the mixing ratio among mineral materials (stone, sand,mineral powder) to satisfy the aggregate composition of asphalt concrete mixture specified for each type
in Table 1 and Table 2, and to find out the optimum asphalt content which satisfies the specifications forasphalt concrete in Table 3 and Table 4
6.2 Asphalt concrete mix design shall apply Marshall method
6.3 Procedure of asphalt concrete mix design: The design is conducted in 3 steps: Cold Mix Design, HotMix Design, and Job Mix Formulae The sequence design is guided in TCVN 8820:2011 and AppendixA
6.3.1 Cold Mix Design: The purpose of this step is to determine the appropriateness of the quality andparticle composition of aggregate types available at the place of execution, the ability to use theseaggregates to produce asphalt concrete satisfying the norms prescribed for asphalt concrete mixtures.Materials at yard of batching plant are used for the design Results of this step is the basis for Hot MixDesign
Trang 106.3.2 Hot Mix Design: The purpose of this step is to determine the grading composition of the aggregatemixture and optimal asphalt content when aggregate is baked Test operation of batching plant shall beconducted on the basis of the Cold Mix Design Aggregate sampling is taken at reserve hopper of hotaggregate for the design Results of this step is the basis for the determination of trial production ofasphalt concrete mixture and trial asphalt concrete paving.
6.3.3 Job Mix Formulae: Based on Hot Mix Design, trial asphalt concrete paving shall be conducted.Based on result of trial asphalt concrete paving, adjustment (if necessary) is conducted to determine thejob mix formulae used for mass construction of asphalt concrete Job mix formulae is the basis for allsubsequent works: production of asphalt concrete mix at the batching plant, construction, qualitymonitoring and acceptance The formulae should indicate the following:
- Sources of aggregate and asphalt used for asphalt concrete mix;
- Test results of physico-mechanical indicators of asphalt, crushed stone aggregates, sand, mineralpowder;
- Composition of mixed aggregates;
- Proportion of aggregates: crushed stone, sand, stone powder at cold and hot hoppers;
- Test results of Marshall method and optimum asphalt content (by percentage of the mass of asphaltconcrete mix);
- The biggest density of asphalt concrete (as a basis for determining Air void);
- Volumetric mass of the asphalt concrete sample, equivalent to the optimum asphalt content (as a basisfor determining the compaction K);
- Construction method at site, such as: asphalt concrete thickness before rolling, rolling diagram, rollingturns per point, pavement roughness, etc
6.4 During the construction process, if there is any change in the input material sources or great variation
in the quality of the materials, asphalt concrete mix design shall be redone in accordance with mentioned steps and redefine the job mix formulae
above-7 Asphalt concrete mix production at batching plant
7.1 Requirements for yard, stocking place of materials
7.1.1 The entire area of batching plant for asphalt concrete mix production must ensure environmentalhygiene, good drainage and clean ground to keep the material clean and dry
7.1.2 Stocking place of crushed stone and sand for batching plant must be large enough, the materialsupply hole for the drum dryer of the mixer should be waterproofed Crushed stone and sand should beseparated to avoid mixing; mixed material shall not be used
7.1.3 Stocking place of mineral powder: Mineral powder must have its own repository with high ground
to avoid being moistened or quality degradation during storage
7.1.4 Area for asphalt heating and storage must be sheltered
7.2 Requirements for batching plant: use cyclic batching plant or continuous mixing plant to produceasphalt concrete mixt Requirements for these two types: Must have control devices, appropriatetechnical features and capacity, ensuring environmental hygiene, the ability to produce asphalt concretemix with quality stability and allowable tolerances comparing to job mix formulae specified in Table 8
in addition, for each type of batching plant, there are some following requirements:
7.2.1 Cyclic batching plant
7.2.1.1 Sieving system: It requires to adjust, supplement and change the sieving system of the batchingplant to suit each type of asphalt concrete whose biggest nominal grain size is different, providing thatthe aggregate after drying will be split into grain groups which ensures that aggregate mix gradingsatisfies the established job mix formulae Lab sieve size and the corresponding converted sieve size forbatching plant are referenced in Appendix B
7.2.2.2 Dust filter system: The return of dust to mix tank for asphalt concrete mix production shall bedetermined by the Employer, depending on quality of the dust The collected dust must be clean withplasticity index ≤ 4
Table 8 – Allowable tolerance comparing to job mix formulae
1 Grading of aggregate particle
Passing amounts correspond to
sieve sizes, mm
- Maximum diameter (Dmax) of asphaltconcrete
0
Trang 112 Asphalt content (% by total mixture mass) ± 0,2
7.2.2 Continuous batching plant: Becase this type does not have sieving system, it does not have hotaggregate drawer Therefore:
7.2.2.1 Grading of cold aggregate should be checked regularly, ensuring absolute stability
7.2.2.2 Quantitative balance system should be checked regularly, ensuring stable aggregate grading speedthroughout the production process
7.3 Production of asphalt concrete mix
7.3.1 Chart of asphalt concrete mix production at batching plant should comply with regulation attechnical specification for batching plant
7.3.2 The production of asphalt concrete mix at the batching plant should comply with the established jobmix formula (definition at 6.3.3)
7.3.3 Allowable tolerance of the aggregate grain gradation and asphalt content of asphalt concrete mixcoming out from mixing tank at batching plant in comparison with job mix formular should not exceedthe value specified in Table 8
7.3.4 The output asphalt concrete mix should satisfy technical specifications for asphalt concretespecified in Table 3 corresponding to DGAC, and Table 4 corresponding to OGAC
7.3.5 Asphalt temperature at preliminary cooking is within 80-100oC for pumping into asphalt kettle.7.3.6 Asphalt temperature when transferring to batching bucket of the mixer shall correspond to asphaltviscosity at about 0.2 Pa.s Depending on the grade of asphalt, the temperature is usually within specifiedtemperature range when mixing in the mixing tank (Table 9)
7.3.7 Asphalt should occupy 75% -80% of asphalt kettle capacity during cooking
7.3.8 Crushed stone grades and sand should be weighed preliminarily at aggregate feeding equipmentbefore bringing into drum dryer, with allowable tolerance of 5%
7.3.9 Aggregate temperature coming out drum dryer should not be over 15°C higher than the batchingtemperature Humidity of crushed stone and sand coming out drum dryer should be less than 0.5%.7.3.10 Mineral powder in cold form, after weighing, is fed directly into the mixing tank
7.3.11 Mixing time of aggregates and asphalt in the mixing tank must comply with the technicalspecifications for the kind of applied batching plant and the type of produced asphalt concrete mix,usually from 30s to 60s Mixing time is adjusted appropriately based on the results of pilot productionand trial paving
7.4 Test for quality control of asphalt concrete mixture at batching plant
7.4.1 Each batching plant of asphalt concrete mixtures should be equipped with fully necessaryexperimental equipment to test material quality, physico-mechanical properties of the asphalt concretemixture at batching plant
7.4.2 Experimental content and frequency for quality control over materials and asphalt concrete mixture
at the batching plant are specified in 9.3 and 9.4
Trang 127.4.3 If the temperature of asphalt concrete mixture is higher than the maximum temperature specifiedfor the mixing stage in the mixing tank, or higher than the maximum temperature when discharging themixture into trunk silo, it shall be rejected (see Table 9 ).
8 Asphalt concrete construction
8.1 Cooperation during the construction
8.1.1 It should ensure smooth operation of the batching plant, means for transporting mixture to the site,paver and rolling facilities It should ensure that productivity of the batching plant is suitable with that ofpaver if overall productivity of the batching plant is low, it should supplement batching plant or order atsome batching plants adjacent to the site of paving
8.1.2 The distance between the batching plant and the construction site must be carefully considered sothat the asphalt concrete mixture being transported to the site can satisfy the temperature specified inTable 9
Table 9 - Temperatures of asphalt concrete mixture corresponding to the construction stages
Construction stage Regulated temperature, corresponding to
asphalt grade, 0 C
2 Discharge mixture into truck silo (or other transport
3 Discharge mixture from truck silo into hopper of
5 Finish rolling (ineffective rolling if the temperature
is lower than the regulated value)
150÷155140÷145
145÷150135÷140NOTE:
The most effective temperature for asphalt concrete rolling and compaction, corresponding to the types
of asphalt:
- Asphalt 40/50: 140OC÷115OC;
- Asphalt 60/70: 135OC÷110OC;
- Asphalt 85/100: 130OC÷105OC
8.2 Requirements for construction condition
8.2.1 Only carry out the asphalt concrete construction when the air temperature is greater than 15oC Donot execute at raining or possible raining condition
8.2.2 It should ensure the spreading and compaction shall be completed within day-time In special case
of night-time construction, it must have sufficient lighting equipment to ensure quality and safety in theconstruction process which shall be approved by Supervision Consultant
8.3 Requirements for trial construction segment
8.3.1 Before mass construction or when using a different type of asphalt concrete, it should carry out trialconstruction on a segment for checking and determining construction technology applied for massconstruction The trial segment should have minimum length of 100m, minimum width of 2 traces ofpaver Trial segment shall be selected right at the site of mass construction or at another site of similarnature
8.3.2 Data from trial construction shall be used for the adjustment (if any) and the approval for massconstruction Items for approval include:
- Job mix formulae (according to 6.3.3);
- Construction plan and technology: materials for tack coat or prime coat; ratio of tack coat or prime coat;allowable time for paving asphalt concrete after tack coat or prime coat application; thickness for pavingasphalt concrete before rolling and compaction; paving temperature; temperature at the beginning and theend of rolling and compaction; work chart of roller types, necessary number of rolling turns; rollingcompaction level; flatness; surface roughness after construction, etc