ASTM D29091a Standard Practice for Bituminous Mixing Plant Inspection (Withdrawn 2000)

Scope 1.1 This practice defines the authority and duties of the inspector at the bituminous mixing plant.. 5.3 Duties-In addition to the responsibilities specified in 5.1 and 5.2, the du

A S T M D290 R E V * A 91 m 0 7 5 9 5 3 0 0 0 8 0 7 0 7 2

1916 Race S t Philadelphia, Pa 19103 Reprinted from the Annual Book of ASTM Standards Copyright ASTM

If not listed in the current combined index, will appear in the nexi edition

Standard Practice for

Bituminous Mixing Plant Inspection’

This standard is issued under the fixed designation D 290; the number immediately following the designation indicates the year of

original adoption or, in the case of revision, the year of last revision A number in parentheses indicates the year of last reapproval A

superscript epsilon (e) indicates an editorial change since the last revision or reapproval

1 Scope

1.1 This practice defines the authority and duties of the

inspector at the bituminous mixing plant These duties are

performed in order to ensure the contractor’s compliance

with the contract and applicable specifications and do not in

any way relieve the contractor of the responsibility to

produce uniform mixtures in compliance with the contract

1.2 The values stated in inch-pound units are to be

regarded as the standard

1.3 This standard does not purport to address all of the

safety problems, if any, associated with its use It is the

responsibility of the user of this standard to establish appro-

priate safety and health practices and determine the applica-

bility of regulatory /imitations prior to use

2 Referenced Documents

2.1 ASTM Standards:

C 136 Method for Sieve Analysis of Fine and Coarse

D 75 Practice for Sampling Aggregates)

D 140 Practice for Sampling Bituminous Materials3

D 242 Specification for Mineral Filler for Bituminous

D 546 Test Method for Sieve Analysis of Mineral Filler for

D 979 Practice for Sampling Bituminous Paving Mixtures3

D 995 Specification for Mixing Plants for Hot-Mixed,

Hot-Laid Bituminous Paving Mixtures3

D 3666 Practice for Evaluating and Qualifying Agencies

Testing and Inspecting Bituminous Paving Material9

Aggregates2s3

Paving Mixtures3

Road and Paving Materials3

3 Terminology

3.1 Descriptions of Terms Specific to This Standard:

3.1.1 engineer, n-the party in responsible charge of the

work or the engineer’s duly recognized or authorized repre-

sentative

3.1.2 inspector, n-the engineer’s (or in the absence of the

engineer, the purchaser’s) authorized representative dele-

gated to perform inspections, tests, and duties hereinafter

indicated

3.1.2.1 Discussion-The inspector shall be qualified as a

technician in accordance with the applicable requirements of

Practice D 3666

I This practice is under the jurisdiction of ASTM Committee D-4 on Road and

Paving Materials and is the direct responsibility of Subcommittee W4.23 on

Plant-Mixed Bituminous Surfaces and Bases

Current edition approved Sept 15, 1991 Published November 1991 Originally

published as D 290 - 28 T Last previous edition D 290 - 9 I

Annual Book of ASTM Standards, Vol 04.02

Atinual Book of ASTM Standards, Vol 04.03

3.1.3 Contractor, n-the party to the contract who has agreed to supply materials and perform work in accordance with the specifications, or the contractor’s duly authorized representative at the plant

3.1.4 laboratory, n-any supervising laboratory duly au- thorized by the engineer to direct and advise the inspector in the discharge of assigned duties

3.1.4.1 Discussion-The laboratory shall satisfy the appli- cable requirements of Practice D 3666

3.1.5 plant laboratory, n-the laboratory operated by or under the direction of the plant inspector at the plant, or the contractor’s laboratory for use by the contractor’s represen- tative for the control of plant production

4 Significance and Use

4.1 This practice defines the authority and duties of the inspection personnel assigned to bituminous mixing plants 4.2 The intent of the practice is to assure by inspection, that the contractor’s facilities, production operations, mate- rials handling, required testing, and finally, the finished mix product comply with applicable specifications

5 Responsibilities and General Duties of Inspector

5.1 Authority-In the absence of authority conferred by

the specifications or contract provisions, the inspector shali

be provided with written authority from the engineer to ensure fulfillment of specifications covering materiais, plant procedure, and products, and reject such materials, proce- dures, and products failing to conform to specifications The inspector shall have available a copy of the specifications and any contract special provisions applying to the particular project, and shall be furnished immediately in writing with copies of all modifications, amendments, and instructions affecting the product of the plant The inspector shali recognize the right of the contractor to use such apparatus, methods, and personnel as deemed proper, provided that no

specification requirements are thereby violated Any appeal

on the part of the contractor from rejections shall be made in writing to the engineer, with a copy to the inspector, unless otherwise provided in the contract

5.2 Cooperation -The plant inspector shall cooperate with the contractor in every reasonable way to obtain efficient and economical plant operation consistent with production of a mixture of satisfactory quality, and with the paving inspector on matters of mutual concern relating to obtaining a mixture of satisfactory placement characteristics, ail within the limits of the specifications

5.3 Duties-In addition to the responsibilities specified in 5.1 and 5.2, the duties of the plant inspector shall be: 5.3.1 To ensure that the plant is equipped and operated at all times in conformity with the specifications (Section 6),

NOTICE: This standard has either been superseded and replaced by a new version or discontinued

Contact ASTM International (www.astm.org) for the latest information

A S T M D290 R E V * A 91 H 0 7 5 9 5 3 0 0080708 4 9

Fine aggregate (cold feed) Practice D 75 Case IA-25 Ib (1 1.3 kg)

Case ilB-5 ib (2.3 kg)

preliminary or first shipments from given source and when source of supply changes, when material characteristics change, or by cpeciai instructions from engineer

laboratory or piant laboratory

Coarse aggregate (wid Same as for Fine Aggregate Case IA-50 ib (22.7 kg) same as for fine aggregate laboratory or plant

Aggregates (plant bins) By use of approved sampling

device capable of obtaining a representative bin sample

5 (2.3 kg) to 35 Ib (15.9 kg) or at least daily more depending on maximum

particle size as required under Method C 136

laboratory or piant laboratory plant laboratory

Bituminous material Practice D 140 1 qt (1 L) each car, tank truck, or boat plant laboratory Finished mixtures: Practice D 979

A To determine aver-

age daily analysis

of mixture

B For determination of

uniformity of indi-

vidual or different

batches

Practice D 979 A Daily

B As directed

laboratory

Pavement sample Practice D 979 1 square piece of size specified as directed laboratory

by Practice D 979

A When job-mix is formulated by Laboratory

When job-mix is formulated by Contractor

5.3.2 To obtain samples as required for testing at the plant

laboratory or submission to the laboratory (Section 7),

5.3.3 To inform the contractor when mixture or condi-

tions violate specifications and disapprove subsequent pro-

duction if corrections are not made (Section 8),

5.3.4 To conduct tests to check the adequacy of ( I )

materials to be used in mixture production and (2) plant

control in maintaining a mixture which is in conformance

with the job-mix formula and tolerance limits for uniformity

(Section 9),

5.3.5 To maintain required inventory and production

records (see 10 i), and

5.3.6 To submit daily reports (see 10.2 and 10.3)

6 Plant Equipment and Operation

6,l General requirements for plant equipment shall be

determined in accordance with Specification D 995 and

supplementing contract requirements

6.2 The inspector shall ascertain as early as possible, by a

thorough inspection of the plant site, plant, and appurte-

nances, that all elements are in compliance with the contract

Specific attention shall be given to materials storage and

handling, cold aggregate feeds, drier, mixture production

plant, batching and mixing components, truck scales (when

required), and hauling units The inspector shall witness

checks on the accuracy of the scales, using standard weights,

and of volumetric meters if used in the proportioning of

mixtures During the operation of the plant, a periodic check

shall be made on the accuracy of scales or meters used in

determining the mass or volume of each component mate-

rial

7 Sampling

7: 1 Materials (General):

7.1.1 A recommended schedule of sampling is indicated

in Table 1, Index of Sampling

7.1.2 As far as possible in advance, but within the time limitation imposed by contract requirements, representative samples of each material proposed for use in the bituminous mixture shall be obtained by, or under approval and obser- vation of, the inspector and submitted to the laboratory or tested by the inspector as directed

NOTE 1-Requirements for lead time, she of samples, and specific

sampling procedures will vary with contracting agencies, for example, different conditions will prevail as between job-mix formulation by the contractor or the engineer,

7.1.3 Should the source of supply of any material, or the characteristics of any material affecting specification require- ments change from that represented by the initially sub- mitted samples, new samples shall be submitted to the laboratory by the inspector

7.1.4 Daily control samples of bituminous material and mixtures shall be collected and, at the end of the day’s work, forwarded to the laboratory without delay

NOTE 2-When forwarding samples of crude asphalt, refined asphalt, hard natural asphalt, oxidized asphalt or any other bituminous materials

in inspections covering the production of bituminous pavements incor- porating such materials, information shall also be furnished relative to the proportions by mass being used so that proper combinations can be

made for analysis and check determinations

7 -2 Bituminous Mixtures:

7.2.1 Samples of bituminous mixtures shall be taken by the contractor daily, or as directed, and witnessed by the inspector for the purpose of checking average aggregate grading, and if desired, bituminous material content of the produced mixture by means of extraction procedures Sam- ples may also be taken, if directed, to determine uniformity within a batch, or batch-to-batch (time-to-time for contin- uous mixing plants),

7.2.1.1 In the case of plants automatically recording batch

A S T M D290 R E V * A 91 0 7 5 9 5 1 0 0080709 b

4m D290

mass of aggregate and the bituminous material, the engineer

may elect to check bituminous material content of the

mixture on the basis of batch mass, or comparison of actual

versus theoretical consumptions, instead of extraction tests

on samples of produced mixture

7.2.2 Sampling of bituminous paving mixtures shall be

done in accordance with Practice D 979, except as modified

below, for determination of within batch variation

7.2.3 Composite Sample-Samples obtained for the pur-

pose of checking aggregate grading and bituminous material

content shall be composited by accumulating fractions from

occasional batches produced during the day, or shorter check

interval, and stored on a metal plate or in another suitable

container The sample, of a size required for testing, shall be

obtained from the accumulated fractional samplings by

quartering after thorough remixing.-To facilitate remixing,

the entire mass should be warmed, avoiding overheating to

the degree necessary to permit satisfactory mixing

7.2.4 Uniformity Samples-Samples used to determine

uniformity within a single batch or from batch to batch shall

be obtained as follows:

7,2.4.1 With Batch Variation-Individual samples shall

be taken by means of a sampling thief from three uniformly

separated locations in a single batch and individually

analysed

7.2.4.2 Batch to Batch Variation-Samples shall be taken

from three or more separate batches throughout a day?s

production by Practice D 979, and remixed, quartered, and

analysed separately

7.2S All sampling of mixtures shall be done with extreme

care to assure representativeness and to preclude contamina-

tion with foreign material Samples submitted to the labora-

tory should be completely identified and accompanied with

required data

7.3 Rejected Materials-Samples of all materials rejected

by the inspector may be forwarded to the laboratory

7.4 Marking Samples-Beginning at the start of opera-

tions on a given contract, the inspector shall assign class

designations to each class of material being sampled, and

each sample selected shall be numbered serially in that class,

continuing numerically until the completion of the work

Care shall be taken that the series of numbers is not broken

or numbers duplicated All samples sent to the laboratory

shall be marked in such a manner as to ensure complete

identification Letters and numbers may be scratched or

punched clearly on tin cans, and marked with ink or paint

on other sample containers or on sections of pavement

8 Preparation of Mixtures

8 I Job-Mix Formula-The inspector shall receive in-

structions from the engineer with regard to the job-mix

formula establishing the percentage of bituminous material

(in relation to either the total mixture or aggregate fraction)

and aggregate gradation, and the specification tolerance

limits for deviation in either bituminous material content or

gradation of the produced mixture from the job-mix values

8.2 Combining Cold-Feed Aggregates-The inspector

shall check to assure that proper attention is given to the

combining of aggregates before they enter the dryer Settings

of feeders should be noted as established by the contractor,

any changes in settings which will change the relative feed

rates between aggregates, and make certain that feeding is continuous and uniform, especially with fine aggregates of high moisture content

8.3 Drying Aggregates-The inspector shall make certain that the aggregate is properly dried and heated to the desired temperature, and that the feed of aggregates to the dryer is consistent with the capacity of the dryer at the given moisture content

8.4 Proportioning by Mass:

8.4.1 The inspector shall witness a check on calibration and accuracy of batching scales, initially and periodically thereafter (at least weekly or when suspect) The batching operation should be observed frequently (continuously when feasible or required) to determine that proper care is being exercised in weighing batches, that aggregate hoppers and bitumen bucket swing freely during weighings, and that the mass indicators read zero after discharge of the batch The inspector should observe that the bitumen bucket is drained completely for each batch and check the tare mass of the empty bucket at frequent intervals to determine if any compensation should be made for the amount of bituminous materia1 clinging to it (This latter element requires more attention in cool weather or at timtwwhen there is.a long interval between loads.)

8.4.2 The inspector shall make certain that the aggregates are deposited in the mixer in a proper sequence for satisfac- tory mixing, that the specified dry-mixing and wet-mixhg periods are accomplished, and that the mixing time is sufficient to produce a homogeneous mixture of uniform color and texture

8.5 Proportioning by Volume:

8.5.1 Aggregate Feed-The inspector shall witness the

?calibration? of the hot-bin and mineral filler feeders at various gate openings or control-arm settings, and check the contractor?s computations for and plot of the calibration graphs relating to volume flow of aggregate from the respec- tive bins to pounds delivered per revolution of the feeder mechanism

8.5.2 Bituminous Material Feed-The inspector shall witness a check on the bituminous material pump delivery per revolution of the aggregate feeder mechanism (con- tinuous mixing plant) or accuracy of the batch meter (Volumetrie metering batch plant)

8.5.3 Batch Proportions-The contractor?s batch propor- tions per revolution shall be subject to the approval of the inspector to assure compliance of the bituminous mixture with the job-mix formula

8.6 Mixtures (General):

8.6.1 The inspector shall ascertain that the aggregates in the hot bins are of known and uniform gradation so they may be batched in the prescribed proportions and consis- tently produce a mixture within specification limits of tolerance

8.6.2 The inspector shall make periodic visual observa- tions of the produced mixture to ensure homogeneous batches of continuously uniform color and texture

8.6.3 When bituminous material is batched by volume, its mass per gallon, at operating temperature, shall be deter- mined and the batching meter adjusted to deliver the required volume at this temperature

8.6.4 It is recommended that, whenever possible, entire

A S T M D290 R E V * A 93 9 0759530 O080730 2 9

4m D290

loads of the mixture proportioned either by mass or volume,

be weighed as a check against individual batches

8.7 Temperature of Materials and Mixtures:

8.7.1 The inspector shall check the temperature of all

ingredients of the mixture, especially mineral aggregates, and

of the mixtures as frequently as possible The inspector shall

assist in keeping temperatures uniform by notifying the plant

foreman of any marked changes observed In the event of

improper temperature, mixing operations shall be discon-

tinued until aggregates of the proper temperature are ob-

tained

8.7.2 The desired temperatures at the plant will depend

upon the kind of mixture being prepared, the type of

bituminous material being used, weather conditions, and the

length of haul The inspector should, therefore, receive

instructions from the engineer as to the temperatures appli-

cable under the various conditions

9 Plant Testing of Materials

9.1 Filler-A minimum of one thoroughly dry sample of

filler, representing each shipment received at the plant, shall

be tested in accordance with Test Method D 546

9.2 Cold Aggregates-Fine and coarse aggregate shall be

tested in accordance with Method C 136 Samples shall be

tested daily, or more often if necessary, in order to provide

data for making adjustments to the combination of aggre-

gates at the cold-feed to the dryer When two or more

aggregates are being received for use in combination, sepa-

rate sieve analysis shall be made on each aggregate and the

required combination to meet the job-mix gradation calcu-

lated and shown on the daily report The proportions in

which all aggregates, including added filler, are combined in

the batch shall also be shown on the report

9.3 Heated Aggregates:

9.3.1 Samples of aggregates as discharged from the hot

storage bins into the mixer shall be taken and tested at least

twice during a full day's operation, or more frequently if

necessary, in order to determine the uniformity and grada-

tion suitability of bin materials to maintain the mixture

within tolerance limits Samples shall be secured from the

stream of aggregate as it flows from the storage bin by any

means which provides a truly representative sample of the

material in the bin

9.3.2 All tests of these materials shall be recorded on the

daily plant report The results will show: ( I ) when blended

materials are being used, whether cold-feed blending is being

carried on satisfactorily and ( 2 ) whether separation of

aggregates by sizes has been uniform If the screened fine aggregate bin is contaminated with coarse aggregate or the screened coarse aggregate bins contain an excessive change in the amount of fine material carried over from the next finer bin, steps shall be taken to determine the cause and to make correction

10 Report

10.1 Production of Pfunt-The inspector shall maintain a

daily record of (i) time and hours of plant productioq, ( 2 )

number of batches (or tons) of the various mixtures pro-

duced, (3) the batch mass proportions of hot-bin aggregates

and bituminous material, and ( 4 ) when possible, a balance sheet comparison of bituminous materials actually used (based on receipts, disbursements, and tank inventories) and theoretically used (based on number of batches produced multiplied by quantity per batch) Other miscellaneous information shall be recorded as required to complete specific report forms

10.2 Daily Reports-At the close of each working day, whether the plant is in operation or not, the inspector shall forward to the engineer and laboratory a consecutively numbered daily report, using a form which gives all the required information All data pertinent to the work not covered by the form should be given on the reverse side of the report sheet, and communications of exceptional impor- tance only should be sent separately from the report When work is suspended for several days, the inspector may not be required to submit reports daily, but the last report should state why and for what periods work has been discontinued The inspector shall retain copies of these reports and communications and, in addition, keep a daily record of all matters pertaining to the work inspected, particularly as to any action in the acceptance or rejection of materials with reasons therefore, instruction or suggestions to the con- tractor, and the receipt of instructions from the engineer or laboratory,

10.3 Report Form-A standard form of report is not practicable for all conditions and types of pavement, but the report form shown in Table 2 is a typical form showing the kind of information which should be included; additional data may be called for as required

,

A S T M D290 R E V * A 91 W 0759530 0080713 4 m

TABLE 2 Bituminous Mixing Plant Inspector's Daily Report

NOTE: This report is intended as a guide When more materials are being used, or more than one mix type is being produced, additional spaces may be necessary

No

Component Materials

Bitumj ous

Materia?

Aggregate TY w Source I 21h in I IVz in I I in 1 3h in I 'h in I 318 in I No 4 I No 8 I No 16 I No 30 I No 50 INo IMINO 200

Cornbiped Coarse % ' Fine -%

Gradaiion I n t e r m e ~ e -% Filler % ,

Job Mix

Formula

Analysis of Hot Bin Aggregates

Sand Equivalent Value Correction Factor From Washed Analysis (No, 200) -

Batch Weights, Ibs, or Ibs Der revolution

I Filler Bituminous Material Total

I

Analysis of Mix

Temperature of Mix, 'F

~ ~~ ~

Characteristics of Mix

S cimen Theoretical

Value

R p w

Stability .O1 inch Sample Time or Theoretical

Location Load No Density

From Truck

~ _ ~~

Remarks

Tons Total

Signed

Plant Inspector, Resident Engineer, etc

A S T M D290 R E V * A 93 W 0 7 5 9 5 3 0 0 0 8 0 7 3 2 b

4m D290

The American Society for Testing end Meteriais tekes no position respecting the veiidity of any patent rights asserted in connection with any item mentioned In thls stenderd Users of this stenderd ere expressly edvised that determination of the velldity of eny such Petent rights, and the risk of infringement of such rights, are entirely their own responsibility

This stendard is subject to revision et any time by the responsible technlcei committee and must be reviewed every five yeers end

if not revised, either reepproved or withdrawn Your comments are invited either for revision ofthis standard or for additional standards and should be addressed to ASTM Headquarters Your comments wlll receive careful consideration at e meeting of the responsible technical committee, which you may attend If you fee/ that your comments have not received a fair hearing you should meke your