STANDARD PRACTICE FOR CONCRETE PAVEMENTS

8/21/2019 STANDARD PRACTICE FOR CONCRETE PAVEMENTS

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ARMY TM 5-822-7AIR FORCE AFM 88-6, Chap. 8

DEPARTM ENTS OF THE ARMY AND THEAIR FORCE TECHNICAL MANUAL

STANDARD PRACTICE FOR CONCRETE PAVEMENTS

DEPARTM ENTS OF THE ARMY AND THE AIR FORCE

AUGUST 1987


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REPRODUCTION AUTHORIZATION/RESTRICTIONS


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TECHNICAL MANUAL

No. 5-822-7

AIR FORCE MANUAL

No. 88-6, Chapter 8

HEADQUARTERS

DEPARTMENTS OF THE ARM

AND THE AIR FORCE

Washington, DC 16 August 198


P a r a g r a p h P a

P U R P O S E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SCOPE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

RESPONSIBILITIES, STRENGTH, AND AIR CONTENT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

CEM EN T . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A G G R E G A T E S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ADMIXTURES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

POZZOLANS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

MISCELLANEOUS MATERIALS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

WATER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SAMPLING AND TESTING OF MATERIALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .DELIVERY AND STORAGE OF MATERIALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

GRADE CONTROL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .P ROPORTIONING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SUBGRADE, BASE, FORMS, AND STRING LINES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .BATCHING AND MIXING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .PLAC ING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

FIELD TEST S P ECI M EN S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

F I N I S H I N G . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .CURING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .GRADE AND SURFACE -SMOOTHNESS REQUIREMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .TOLERANCES IN PAVEMENT THICKNESS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .REPAIRS OF DEFECTIVE PAVEMENT SLABS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .J O I N TS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

PAVEMENT PROTECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .MEASUREMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

APP ENDIX A: REFERENCE S. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

APPENDIX B: THIN BONDED RIGID OVERLAYS FOR RIGID PAVEMENTS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

APPENDIX C: STEEL-FIBER- REINFORCED CONCRETE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

APPENDIX D: ROLLER-COMPACTED CONCRETE PAVEMENTS; DESIGN AND CONSTRUCTION.. ..........

1

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AB

CD


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Figure 1.

2.3.

D-1.

D-2.

D-3.

D-4.

D-5.

Table 1.

2.

3.4.

5.

6.

7.

8.

C-1.

C-2.D-1.

LIST OF FIGURES

Prediction of concrete rate of evaporation.

Air Force runway grooving requirements.Special joint between new and exist ing pavement.

Typical layout for RCCP test section.

Compaction of first paving lane.

Compaction of interior paving lanes.

Construction of a cold joint.

Two-lift cold joint preparation.

LIST OF TABLES

Approximate relat ion between water-cement rat io and strengths of concrete

Coarse aggregate size groups

Grading of coarse aggregateDeleterious materials in coarse aggregates for airfield and heliport pavements

Deleterious materials in coarse aggregates for other pavements

Grading of f ine aggregate

Deleterious substances in fine aggregate

Surface smoothness - airfield and heliport pavements

Selected characteristics of fiber-reinforced airfield pavements

Interim suggested maximum joint spacing for steel-fiber-reinforced concrete

Vibratory rollers used in RCCP construction


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1. Purpose. This manual provides information on the

materials and construction procedures for concrete

pavements.

2. Scope. This manual describes the constituents to

be used in concrete, the procedures to be used in

manufacturing concrete, and the equipment and

procedures to place, texture, and cure concrete for

pavements.

3. Responsibilities, strength, and air content.

a. Responsibility for mixture proportioning. The

responsibility for mixture proportioning must be

clearly assigned to ei ther the contractor or the

contracting officer in the project specifications.

When the contracting officer is responsible for

mixture proportioning, he will approve all concrete

materials as well as determine and adjust propor-

tions of all concrete mixtures as necessary to obtain

the strength and qual i ty of concrete required for the

pavements. Cement wil l be a separate pay i tem in

the contract. When the contractor is responsible for

mixture proportioning, he will control all proportions

of the concrete mixture necessary to obtain the

strength and qual i ty of the concrete required for the

pavements, and cement wil l not be a separate pay

i tem in t he contr act . H owever, th e contr acting officer

is responsible for approving the quality of all

materials the contractor uses in the concrete.

b. Approval responsibility. The contracting officer

is responsible for approval of all materials, mixture

proportions, plants, construction equipment, and

construction procedures proposed for use by thecontractor. The contractor must submit proposed

mixtures if he is responsible for mixture propor-

tioning; samples of al l materials; and detai led

descriptions of all plants, construction equipment,

and proposed construction procedures prior to the

start of construction.

c. Flexural strength. Structural designs are based

on flexural strengths that the concrete is expected

to obtain at 28 days for road pavements and 90 days

for airfield pavements. These ages are not adequat

for qual i ty control in the field since a large amoun

of low-strength concrete could be placed befor

strength tests on samples revealed the problem

Correlations can be established between a 14-da

strength and the 28- or 90day strength used i

design, and this correlated 14-day strength can b

used as a strength check for a more t imely concre

mixture control in the field.

(l.) Materials and flexural strength. To selec

s u i t a b l e f l e x u r a l s t r e n g t h s f o r t h e d e s i g n opavements and for inclusion in contract specific

tions, the contracting officer should have reliab

information regarding flexural strengths obtainab

with acceptable concrete mater ials which are avai lab

in the vicinity of the project. Typical design value

for flexural strength of paving-qual i ty concre

vary from 500 to 750 pounds per square inch (psi)

Numerous tests indicate considerable variation

the flexural strength of concrete when differen

aggregates or di fferent cements are used. There ar

some indications that aggregate shape and modulu

o f e l a s t i c i t y a r e r e l a t i v e l y m o r e i m p o r t a n t i

concrete flexural strength than in compressiv

strength. Also, after optimum flexural strength

reached, there usual ly is l i t t le increase in strengt

even with a large increase in cement content. Mixtur

proportioning studies will be made in accordanc

with ACI 211.1 (see app A for referenced publication

to determine the flexural strengths to be used fo

the design of the project. The water-cement ratio

strength relations for mixture proportioning in AC

211.1 are given in terms of compressive strength

Tab l e 1 g i ves som e approx i m ate gu i dance fo

relating the concrete modulus of rupture to th

compressive strength-water cement rat io relat ionships given in ACI 211.1. All aggregates, cementit iou

materials, and admixtures used in the mixtur

proportioning studies will be representative

ma terials a vai lable for use in pavement constructio

In selecting a flexural st rength for pavement desig

suitable al lowance wil l be made for variat ions

strength indicated by tests of di fferent combin

tions of aggregate and cement. Pavement desig

will be based on a realistic and economical strengt

obtainable with avai lable materials.


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Tabl e 1. Approximate relati on between water-cement r ati o and strengths of concrete (modified fr om ACI 211.1)

(eq 1)


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TM 5-822-7/AFM 88-6, Chap.

characteristics of freshly mixed concrete and is

required for the freezing and thawing resistance of

hardened concrete. The use of entrained air in

concrete will reduce strength, but because of the

improved workability in the freshly mixed concrete,adjustments in aggregate proportions and reduction

of water are normally possible that wil l negate or at

least minimize the loss of strength. Proper propor-

tioning and control of the air-entrained concrete

mixture are essential in order to derive maximum

benefi ts from improvement in the placabil i ty and

durabil i ty of concrete with a minimum effect on

flexural strength.

(2.) Percentage of air content. The specified air

c on t e n t w i l l b e 6 1 p e r ce n t f o r co n cr e t e

pavements located in regions where resistance to

freezing and thawing is a prime consideration, and

wil l be 5 1 percent for concrete pavementslocated in regions where frost act ion is not a factor

an d a ir entra inment is used primari ly to improve the

workability and placability of freshly mixed concrete.

Air content will be controlled in the field at the point

within the specified range most appropriate for local

conditions depending upon the severity of exposure

and the qual i ty and maximum size of aggregate . I f

slag aggregate is used, the air content wil l be deter-

mined by the volumetric method as described in

ASTM C 173. Where the aggregate is of compara-

tively poor qua l i ty or wh en the m aximum size is 1%

inches or less, the air content will be controlled at 6

1 percent . In such insta nces, where resistance to

freezing and thawing is not a prime consideration,

the a ir content wil l be 5 1 percent . I f furth er

reduction in the air content or the use of non-air-

entrained concrete is necessary, prior approval will

be obtained from HQDA (DAEN-ECE-G), Wash-

ington, DC 20314-1000 or the appropriate Air Force

major command.

e. Cement content. Either the contractor or the

contracting officer may be responsible for mixture

proportioning. When the contractor is responsible

for mixture proportioning, no separate payment wil l

be made for cement. When the contracting officer isresponsible for mixture proportioning, no limits for

the quantity of cement content will be included in

the contract specificat ions; the quanti ty of cement

used per cubic yard of concrete will be determined

by the contracting officer, and cement will be paid

for under a separate bid item. When the concrete

proposed for use on a paving project has a cement

content of less than 470 pounds per cubic yard, prior

approval will be obtained from HQDA (DAEN-

ECE-G) or the appropriate Air Force major comma

When concrete proportioning is the responsibility

the contractor and the cement content is less th

470 pounds per cubic yard, the results should

v e r i f i e d b y t w o C o r p s o f E n g i n e e r s D i v i s ilaboratories or commercial laboratories prior

submittal. The results of mixture proportioni

studies for proposed aggregates and cements a

the results of qual i tat ive tests on aggregates and

result ing concretes wil l be submitted with reque

for approval .

4. Cement.

a. Five portland cements designated as Types

through V are marketed today. ASTM C 150 provid

a detailed specification for these cements. Type

portland cement is common or ordinary cement th

is supplied unless another type is specified. Typeis modified portland cement that provides moder

resis tance against sul fa te a t tack and a lower heat

hydration than Type I cement. It is common f

cement to be manufa ctured to meet t he physical a

chemical requirements of both Type I and II cemen

b. Type III cement is high early-strength ceme

Ultimate strength is about the same as Type

cement, but Type III cement has a 3-day compress

s t r e n g t h a p p r o x i m a t e l y e q u a l t o t h e T y p e

cements 7-day strength. The cost of Type

cement in lieu of Types I or II cement can only

justified when early strength gain is needed to op

pavements to traffic or the high heat of hydration

needed for cool construction periods. Type

cement has a low heat of hydrat ion that may

useful in mass concrete but is not likely to

encountered in pavement construction. Type

sulfate-resistant cement should be used when t

concrete will be exposed to severe sulfate attac

The potential for severe sulfate at tack exists wh

the concrete is exposed to water-soluble sulfate

soil or water in excess of 0.20 percent or 1,500 pa

per million. The potential for moderate sulf

attack exists for sulfate contents in excess of 0.1

or 150 parts per million.c. High alumina cement, also known as alumino

or calcium aluminate cement, gains most of

strength in one day , has a high exotherm, i s resist

to chemical at tack, and is a refractory materi

When exposed to warm, moist conditions, it w

undergo a long-term strength loss. High alumi

cement may find some specialized applications

pavement construction where i ts rapid stren

gain, high exotherm, or refractory propert


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TM 5-822-7/AFM 88-6, Chap. 8

outweigh its cost and long-term strength loss.

d . There a re a l so som e expans i ve cem ents ,

designated as Types K, M, and S in ASTM C 845,

that may find some applicat ion where concrete

shr i nkage needs to b e m i n i m i z ed or avo i ded .However, there is little experience with these

cements, and they wil l require careful investigation

before use in pavement construction.

e. At least one United States manufacturer is

actively promoting a slag cement made by grinding

iron blast furnace slag. This may be substituted for

up to 50 percent of the portland cement in a pavement

mixture if tests show the required final properties

are achieved in the hardened concrete. Preblended

mixes of portland-pozzolan (Type IP), and portland-

slag cements (Type IS) are described in ASTM C 595

and are acceptable for use in pavements.

5. Aggregates.

a. Approval of aggregates. The contractor will use

aggregates from approved sources. If the contractor

proposes to use aggregates from an unapproved

source, the Government will be responsible for

conducting tests to determine whether the proposed

a ggregat es wil l meet th e requirements of the project .

Sampling and aggregate del ivery costs wil l be borne

by the contractor. The contract specifications will

state aggregate sample size, del ivery location, and

required evaluation time for the proposed aggre-

gates. For small jobs requiring 1,600 cubic yards or

less of concrete, all tests for aggregates from an

unapproved source will be done by the contractor.

b. Quali ty. Aggregates must general ly meet the

requirements of ASTM C 33, as modified in the

following paragraphs. These requirements can be

adjusted as necessary to reflect local experience

with specific aggregates to insure economical use of

aggregates to meet project requirements. The

magnesium or sulfate soundness test (ASTM C 88)

required in ASTM C 33 has not been consistently

successful in identifying frost-resistant aggregate.

Consequently, i f an otherwise suitable aggregatefai ls this test , i t should be further investigated

using freezing and thawing tests as described in

ASTM C 666 or ASTM C 682 before it is finally

rejected. Similarly, i f an otherwise suitable aggre-

gate fails the Los Angeles (LA) abrasion test

(ASTM C 131 or C 535), it can be accepted if it has a

history of local use showing that it can be processed

without unacceptable degradation and that i t is

durable under weathering and traffic condit ions

comparable to the project under investigation.

c. Recycled concrete as aggregate. E x i s t i n g

concrete may be taken up, crushed to suitable

gradation, and re-used as concrete aggregate. I t

must meet al l the requirements for gradation andquali ty that conventional aggregates must meet.

All reinforcing steel should be removed. During

crushing, hammermill secondary crushers tend to

produce excess fines and should not be used. The

recycled concrete aggregates will not normally

require washing unless they ha ve been contamina ted

with base or subgrade material . I f the original pave-

ment that is being recycled is D-cracked, then the

concrete should be crushed to a maximum size of

inch. When crushed concrete is being used as fine

aggregate, the inclusion of some natural sand may

be required to improve the new concrete mixtures

workabil i ty.

d. Alkali-aggregate reactions. Minerals in some

aggregates can chemical ly react with the cement

alkal is, result ing in an increase in volume that

places the concrete under expansive stresses which

may result in map cracking, popouts, strength loss,

and concrete expansion. Once started, the reaction

and the resulting progressive deterioration of the

concrete cannot be stopped. These reactions are

general ly associated with aggregates containing

poor l y o rdered fo rm s o f s i l i c a , such as opa l ,

chalcedony, chert, or flint (alkali-silica reaction),

complex layer-lattice, and silicate minerals such as

graywackes, phyllites, siltstones, or argillites (some-

times differentiated as alkali-silicate reaction), or

argillaceous, dolomitic limestone (alakali-carbonate

rea ction). A petrogra phic investiga tion in conjunction

with results of tests in accordance with ASTM C 227

for alkali-silica expansion and ASTM C 586 for

alkali-carbonate expansion is the most promising

approach for identifying these problems. If possible,

reactive aggrega tes should be avoided. If t hey cannot

be avoided, low-alkali cement should be specified. If

low-alkali cement is not available or is overly expen-

sive, some pozzolans and slag cements have been

successful in countering alkali-silica reactions, orreactive aggrega te ma y be blended w ith non-reactive

aggregate to lessen the effect of the reactions.

e. Coarse aggregate.

(l.) Composition. Coarse aggregate may be

natural gravel , crushed gravel , crushed stone, crushed

recycled concrete, or iron blast furnace slag. The

crushing of gravel tends to improve the qual i ty and

the bond characterist ics and general ly results in a

higher flexural strength of concrete than i f uncrushed

4


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TM 5-822-7/AFM 88-6, Chap.

gravel is used. When mixture proportioning studies

or local experience indicates that a low flexural

strength wil l be obtained with uncrushed gravel , the

possibility of obtaining higher strength by crushing

the gravel wil l be investigated. Elongated part icleswith a widthto-thickness rat io in excess of 3 may

not exceed 20 percent by weight as determined by

CRD-C 119. This requirement attempts to avoid

introducing structural planes of weakness in the

finished concrete, workability problems associated

with an excess of particles of these shapes, and

durabil i ty problems that may develop i f air and

water are trapped under flat and elongated part icles.

(2.) Size and grading. The maximum size of the

coarse aggregate used in pavement concrete should

not exceed one-fourth of the pavement thickness. In

no case will the coarse aggregate exceed a 2-inch

maximum size. However, for pavement constructionin areas where aggregate popouts have been a problem

or may occur, the coarse aggregate wil l not exceed

1 -inch nominal maximum size. In area s where

D l ine cracking in pavements has been a problem

limestone aggrega tes should not exceed -inc

nominal maximum size and should be of low absor

tion. When the nominal maximum size of coars

aggregate i s greater than 1 inch, the aggregateshall be furnished in two size groups as shown i

table 2, with gradings within the separated siz

groups conforming to the requirements of table 3

Where local practice provides size-group separation

other than as shown in table 2, local size grading

may be specified if approximately the same siz

ranges are obtained and the grading of coarse aggr

gate when combined and batched for concrete is a

required by mixture proportioning. For projec

requiring 1,600 cubic yards or less of concret

special grading requirements for coarse aggrega

according to local practice may be substituted fo

the gradings shown. Local S ta te Department Transportation specifications for gradings may b

used for those jobs requiring 1,600 cubic yards o

less of concrete.

Table 2. Coarse aggregate size group s

L

Nominal Maximum Size Size Groups

1 in . No. 4 to in . in . t o 1 i n.

2 in . No. 4 to 1 in.

1 in. to 2 in.


10/55

TM 5-822-7/AFM 88-6, Chap. 8

Tabl e 3. Grad in g of coarse aggregate

S i e v e S i z e

U . S . S t a n d a r d

S q u a r e M e s h

P e r c e n t a g e b y W e i g h t P a s s i n g I n d i v i d u a l S i e v e s

No. 4 to

3 /4 i n .

No. 4 to

1 i n .

3 /4 i n . t o 1 in. to

2 i n .1 - 1 /2 i n .

2 - 1 /2 i n .

2 i n .

1 - 1 /2 i n .

1 i n .

3 /4 i n .

1 /2 i n .

3 /8 i n .

N o . 4

N o . 8

100

9 7 3

50 20

7 7

- - - - - -

100- - - -

100

9 7 3100

9 5 5 - -

- - - -

3 3- - - -

- - - -

- - - -

(3.) Deleterious substances.

(a) Pavements used by aircraft. Table 4 liststhe common deleterious substances and specifies

limits for these materials. The performance history

waive table 4 requirements for Air Force pavements.

Upon request, the AFRCE and the using command

will be furnished available engineering information

on local aggregates and behavior records on pave-

ments made from them. A copy of the instructions

and the revised requirements will be furnished for

in format ion to the HQDA (DAEN-ECE-G) or

AFESC as applicable. In the case of Air National

Guard and Army pavements, the using command

will be furnished information on the costs of aggre-

gates complying with specification requirements

and on less costly local aggregates along with

behavior records on pavements made with local

aggregates. However, requirements will be waived

only if requested by the Air National Guard BaseDetachment Commander or the Army Installation

Commander with his assurance that operational

requirements w ill be sat isfied by a performa nce that

is equal to that of existing pavements constructed

with these less costly aggregates. Requests will be

submitted for approval to HQDA (DAEN-ECE -G)

with proposed specification requirements, compara-

tive cost estimates, and evidence that operational

requirements will be satisfied.

o f l o c a l a g g r e g a t e s c o n t r i b u t i n g t o p a v e m e n t

defects will be the determining factor in setting the

limits for deleterious substances. The limits are

intended to eliminate popouts and weatherouts in

airfield pavements. Other deleterious substances

known to contribute to popouts will be identified by

the contracting officer, and suitable limits will be

specified. Calcium oxide (CaO) and magnesium oxide

(MgO) or a mixture thereof, in lumps, representing

the hard burned oxides from fluxing stone or refrac-

tory brick should be added to the list of deleterioussubstances if air-cooled blast furnace slag is used as

the a ggregate. S ince the t ypes of ma terials producing

popouts will vary for different areas, some adjust-

ments of the limits may be desirable for individual

projects. Reductions in specified limits may be

made as necessary, but increases to permit the use

of loca l aggregates tha t have an acceptable experience

record will be governed by the following procedures.

Air Force Regional Civil Engineers (AFRCE) have

been authorized to instruct division engineers to

6


11/55

TM 5-822-7/AFM 88-6, Chap.

Table 4. Deleteri ous materi als i n coarse aggregates for ai rfi eld and heliport pavements.

Areas with Areas with

Major Popouts Minor Popouts

S ev er ea Moderate

aS ev er e

aModerate

a

Materia ls Wea t her Wea t her Wea t her Wea t her

Clay lumps 0.2 0.2 2.0 2.0

S h a l eb 0.1 0.2 1.0 1.0

M a t e r i a l f i n e r 0.5 0.5 1.0 1.0than No. 200 sieve

c

L igh t w eig h t pa r t i cles 0.2 0.2 0.5 0.5

C la y i r on s t on e 0.1 0.5 1.0 1.0

(Continued)

aS ev er e , m od er a t e, a n d m il d wea t h er a r e d ef in ed a s fol lows :

Air Freez- Average Precipitation for a Singleing Index Mont h D ur ing P eriod--1 Mont h B efore

Weather f or C ol de st Aver age D a te of F ir st Killin g F rost

S ev er i t y Yea r in 30* t o Aver ag e D a te of La st Killin g Frost

M o d e r a t e 500 or less Any amount

Modera t e** 501 or more Less than 1 inch

S evere 501 or more 1 inch or more

* Ca lcula ted a s des cribed in TM 5-818-2/AFM 88-6, Ch a pter 4.** In poor ly dra ined a r eas , the wea ther shou ld be cons idered severe

even though the other criteria indicate a rating of moderate.

bShale is defined as a fine-grained thinly laminated or fissile sedimentary rock.

It is commonly composed of clay or silt or both. It has been indurated by compac-tion or by cementation, but not so much as to have become slate.

cLimit for material finer than No. 200 sieve will be increased to 1.5 percent forc r u s h ed a gg r ega t e s i f t h e f i n e m a t e r i a l c o n s i s t s o f c r u s h er d u s t t h a t i s e s s en -t i a l l y f r ee f r o m c l a y o r s h a l e .

dThe separation medium shall have a specific gravity of 2.0. This limit does not

apply to coarse aggregate manufactured from blast-furnace slag unless contaminationi s ev i d en t .

e Clay ironstone is defined as an impure variety of iron carbonate, iron oxide,hydrous iron oxide, or combinations thereof, commonly mixed with clay, silt, ors a nd . I t com m on ly occu r s a s d u ll , earthy particles, homogeneous concretionarym a s s es , o r h a r d s h e l l p a r t i c l e s w i t h s o f t i n t e r i o r s . Other names commonly used forc l a y i r o n s t o n e a r e c h o c o l a t e ba r s a n d l i m o n i t e c o n c r e t i o n s .


12/55

TM 5-822-7/AFM 88-6, Chap. 8

Areas with A r ea s w i t h

M a t e r i a l s

Cher t a nd/or cher t y

s tone ( less than

2 .50 sp . gr . SSD)f

C l a y s t o n e , m u d s t o n e ,

a n d /o r s i l t s t o n e g

S h a l y a n d /o r a r g i l l a -h

ceous l imes tone

O t h er s o f t p a r t i c l e s

T o t a l o f a l l d e l e t e r i -

ous subs tancesex c l u s i v e o f m a t e-r i a l f i n e r t h a nNo. 200 s ieve

Ma jor P opout s Minor P opout s

S e v e r ea

M o d er a t ea

S e v e r ea M o d er a t e

a

Wea t h er Wea t her Wea t her Wea t her

0.1 0. 5 1. 0 5. 0

0.1 0.1 1.0 1.0

0 . 2 0. 2 1.0 2.0

1. 0

1. 0

l . 0

2. 0

1.0

3. 0

2. 0

5. 0

f C h er t i s d e f i n ed a s r o c k c o m p o s ed o f q u a r t z , c h a l c ed o n y , o r o p a l , o r a n y m i x t u r eo f these forms o f s i l i ca . I t i s v a r i a b l e i n co l or . T h e t ex t u r e i s s o f i n e t h a t

t h e i n d i v i d u a l m i n e r a l g r a i n s a r e t o o s m a l l t o b e d i s t i n g u i s h e d b y t h e u n a i d e d e y e .I t s h a r d n e s s i s s u c h t h a t i t s c r a t c h e s g l a s s b u t i s n o t s c r a t c h e d b y a k n i f e b l a d e .I t m a y c o n t a i n i m p u r i t i e s s u c h a s c l a y , c a r bo n a t es , i r o n o x i d es , a n d o t h er m i n -e r a l s . O t h er n a m e s com m on l y a p pl ie d t o v a r i et i es of ch e r t a r e f li n t , ja s p er ,a g a t e , o n y x , h o r n s t o n e , p or c el l a n i t e , n o v a c u li t e , s a r d , ca r n e l i a n , p la s m a , b l oo d -

s t o n e , t o u c h s t o n e , c h r y s o p r a s e , h e l i o t r o p e , a n d p e t r i f i ed wo o d . C h er t y s t o n e i s

d e f i n ed a s a n y t y p e o f r o c k ( gen er a l l y l i m es t o n e) wh i c h c o n t a i n s c h er t a s l en s esa n d /o r n o d u l es or i r r egu l a r m a s s es p a r t i a l l y o r c o m pl e t e l y r ep l a c i n g t h e o r i g i n a ls tone . SSD = s a t u r a t e d s u r f a c e d r y .

gC l a y s t o n e , m u d s t on e , o r s il t s t o n e i s d ef i n ed a s a m a s s i v e fi n e -g r a i n e d s e d im e n t a r yr o c k wh i c h c o n s i s t s p r ed o m i n a t e l y o f c l a y o r s i l t w i t h o u t l a m i n a t i o n o r f i s s i l i t y .I t m a y be i n d u r a t ed e i t h e r by c o m p a c t i o n o r by c em en t a t i o n .

h S h a l y l i m es t o n e i s d e f i n ed a s a l i m es t o n e i n wh i c h s h a l e o c c u r s a s o n e o r m o r e

th in beds of l am ina e . These laminae may be regu la r or very ir regu la r and may be

s p a c ed f r o m a f ew i n c h es d o wn t o m i n u t e f r a c t i o n s o f a n i n c h . Argi l l aceous l ime-s t o n e i s d e f i n ed a s a l i m es t o n e i n wh i c h c l a y m i n er a l s o c c u r d i s s em i n a t ed i n t h estone in the amount of 10 to 50 percent by weight of the rock; when these make upfrom 50 to 90 percen t , the rock i s known as ca lca reous (or do lomi t i c) sha le (orc l a y s t o n e , m u d s t o n e , o r s i l t s t o n e) .


13/55

TM 5-822-7/AFM 88-6, Chap.

(b) Other pavements. For other pavements, be identified by the contracting officer, and suitab

the limiting amounts of deleterious substances in limits will be specified and materials defined whe

each size of coarse aggregate will be specified as necessary.

shown in table 5. Other deleterious substances will

Table 5. Deleterious materials in coarse aggregates for other pavements

M a t e r i a l P e r c e n t a g e b y W e i g h t

C l a y l u m p s a n d f r i a b l e p a r t i c l e s 2 .0

M a t e r i a l f i n e r t h a n N o . 2 0 0 s i e v ea 1. 0

L i g h t w e i g h t p a r t i c l e s 1 . 0

O t h e r s o f t p a r t i c l e s 2 .0

N o t e :

aL i m i t

T h e t o t a l o f a l l d e l e t e r i o u s s u b s t a n c e s s h a l l n o t e x c e e d

5 . 0 p e r c e n t o f t h e w e i g h t o f t h e a g g r e g a t e . T h e p e r c e n t a g e

o f m a t e r i a l f i n e r t h a n N o . 2 0 0 s i e v e s h a l l n o t b e i n c l u d e d

i n t h i s t o t a l .

f o r m a t e r i a l f i n e r t h a n N o . 2 0 0 s i e v e w i l l b e i n c r e a s e d t o

1 . 5 p e r c e n t f o r c r u s h e d a g g r e g a t e s c o n s i s t i n g o f c r u s h e r d u s t t h a t

i s e s s e n t i a l l y f r e e f r o m c l a y o r s h a l e .

bT h e s e p a r a t i o n m e d i u m s h a l l h a v e a s p e c i f i c g r a v i t y o f 2 . 0 . This

l i m i t d o e s n o t a p p l y t o c o a r s e a g g r e g a t e m a n u f a c t u r e d f r o m b l a s t -

f u r n a c e s l a g u n l e s s c o n t a m i n a t i o n i s e v i d e n t .

(4.) Slag aggregate. Iron ore blast-furnace slag

aggregates vary widely in properties depending on

the manufacturing and cooling processes used. Un-

aged blast-furnace slag may contain free l ime, but

aging reduces this to acceptable levels. Properly aged

iron ore blast- furnace aggregate has a good history

of performance. Slag from steel mills, however, is

not acceptable as concrete aggregate because of the

various oxides it contains.

f . Fine Aggregate.

(l.) Composition and shape. Requirements for

composit ion and part icle shape of f ine aggregate are

purely descript ive, for example, natural a nd/or

manufactured sand, spherical or cubical , and no

limits are shown. A limit will be included for flat and

elongated part icles in fine aggregate, comparable

with the l imit specified for coarse aggregate, when

tests indicate that poor part icle shape wil l affect the

workabil i ty and qual i ty of the concrete. Shape wi

be determined in accordance with CRD-C 120.

(2.) Grading, uniformity of grading, an

deleterious substances. The grading and uni formi

of grading specified in table 6 for fine aggregate a

desirable for pavement concrete and can general

be met at a reasonable cost within the continent

United States. However, i f conformance with the

requirements will result in undue construction cos

and if investigation of the available sources of fiaggregate in the local i ty indicates that l imits oth

than specified are desirable, a request will be su

mitted to HQDA (DAEN-ECE-G) giving comple

results of al l tests conducted to substantiate th

concrete of comparable workabil i ty, durabil i ty, a

strength can be produced without an increase

ce m en t con t e n t . Th e a m o u n t o f d e le t er i ou

substan ces in th e fine aggregat e shal l not exceed th

l imits shown in table 7.


14/55

TM 5-822-7/AFM 88-6, Chap. 8

Tabk 6. Gnad in g of fin e aggregate

S i e v e S i z e , C u m u l a t i ve P er cen t a g e by Wei g h t

U . S . S t a n d a r d S q u a r e M e s h P a s s i n g I n d i v i d u a l S i e v e s

3 /8 i n . 100

No. 4 9 7 2 3

No. 8 8 5 2 5

No. 50 20 10

No. 1 0 0 6 4

N ot e : I n a d d i t i on , t h e f i n e a g g r eg a t e , a s d el iv er e d t o t h e m ix er ,

s h a l l h a v e a f i n e n e s s m o d u l u s o f n o t l e s s t h a n 2 . 4 0 n o r

m or e t ha n 2.90. Th e g r a d i n g of t h e f i n e a g g r e g a t e a l s o

s h a l l b e c o n t r o l l e d s o t h a t t h e f i n e n e s s m o d u l i o f a t l e a s t

n i n e o f t e n s a m p l e s o f t h e f i n e a g g r e g a t e a s d e l i v e r e d t o

t h e m i x e r w i l l n o t v a r y m o r e t h a n 0 . 1 5 f r o m t h e a v e r a g e

f i n e n e s s m o d u l i o f a l l s a m p l e s p r e v i o u s l y t a k e n . T h e

f i neness m odul us sha l l b e de term i ned b y C RD- C 1 0 4

(Appendix A).

Table 7 Deleterious substances in fine aggregate

Materia l Percentage by Weight

Clay lumps and friable part icles 1 . 0

Material finer than No. 200 sieve 3 . 0

Lightweight part icles 0 . 5

Note: The total of all deleterious materials shall not exceed 3.0 percent of the weight of the aggregate.

10


15/55

TM 5-822-7/AFM 88-6, Chap.

g. Aggregate for calibration hardstands. To avoid

inclusion in the pavement concrete of iron oxides or

other iron-rich ma terials ha ving ma gnetic properties

that wil l interfere with the operation of the faci l i ty,

the concrete aggregate proposed for paving calibrationha rdsta nds w il l be subjected t o detai led petrogra phic

analyses in accordance with ASTM C 295 prior to

acceptance. Special attention will be given to the

e x i s t e n c e o f m a g n e t i t e i n g r a n i t e s , h i g h - i r o n

minerals in traprock, pyri te in l imestone, and free

iron or iron oxide in slag aggregate. When a list of

aggregate sources is included in the contract specifi-

cations, the sources not approved for concrete used

in cal ibrat ion hardstands wil l be indicated.

h. Aggregate for power check pads. Concrete that

will be exposed to extended jet engine blast during

maintenance can use igneous rocks with a low silica

content and a high content of ferromagnesian

minerals or slag as aggregate to improve i ts perfor-

mance under high temperature. Aggregates rich in

silica such as quartzite or chert should be avoided.

Aggregate with a high si l ica content such as sand-

stone or granite, especially if coarse grained, can

cause problems. Ca lcar eous a ggregates such a s l ime-

stone or dolomite are acceptable.

6. Admixtures.

a. Admixtures are used to modify properties of

fresh or hardened concrete. Admixtures may be used

to improve workability, control initial set, reduce

heat generation, accelerate strength gain, increase

strength, and improve durabil i ty. Seven chemical

admixtures are l isted for use in portland cement

concrete in ASTM C 494, as follows: Type Awater-

reducing admixture; Type B retarding admixture;

Type Caccelerat ing admixture; Type Dwater-

reducing and retarding admixture; Type Ewater-

reducing and accelerat ing admixture; Type F

water-reducing, high-range admixture; and Type

G w a t e r -r e d u ci n g , h i g h -r a n g e a n d r e t a r d i n g

admixture.

b. Air-entraining admixtures provide resistance

to freezing and thawing and should meet therequirements of ASTM C 260, and will normally be

required in all concrete for pavements. For small

job s under 1 , 6 0 0 cub i c yards , a i r - en t ra i n i ng

cements may be considered. The use of any other

admixture will depend on the economics of its use

and site conditions. The effect of an admixture will

vary, depending on conditions such as cement type,

specific mixture proportions, ambient temperature,

or water qual i ty . Furthermore, an admixture may

affect several qualities of the concrete, and som

desirable properties may be adversely affecte

Consequently, the decision to use an admixtur

must be based on experience and tests with th

cement, aggregates, and admixtures representat ivof those to be used on the project. It must be demon

strated that the final concrete proposed pavemen

quali ty is not adversely affected by the use of an

proposed admixture. More extensive guidance o

admixtures is provided in ACI 212.lR and AC

212.2R.

7. Pozzolans.a. Pozzolans are defined in ASTM C 618

siliceous or siliceous and aluminous materia

which in themselves possess little or no cementitiou

value, but will , in finely divided form and in th

presence of moisture, chemically react with calciu

h y d r o x i d e a t o r d i n a r y t e m p e r a t u r e s t o f o r m

compounds possessing cementitious properties

This ASTM specification recognizes three classes

pozzolan and provides detailed requirements fo

each class. Class N pozzolans are raw or calcine

na tura l pozzolans such a s some diat omaceous ear th

opaline cherts, tuffs, volcanic ashes, clays, an

shales. Fly ash is divided into two classes. Class F

fly ash produced by burning an thra cite or bi tuminou

coal , and Class C fly ash is produced by burning l igni

or subbituminous coal. Environmental Protection

Agency (EPA) guidelines published in 1983 (4CFR, Part 249) require that the use of f ly ash mu

be allowed on all federal projects unless it can b

proven technically unsuitable.

b. Pozzolans may be substi tuted for a maximu

of 25 percent by volume of portland cement in concre

for pavements. If substitution of pozzolan abov

this l imit is contemplated, a thorough test progra

must show that the proposed substi tution l imit w

not adversely affect workabil i ty, admixture perfo

mance strength, and durabil i ty of the final concret

Pozzolans typically have specific gravities appreciab

lower than portland cement, and pozzolan l imits a

expressed as a percent of the volume of cementitioumaterials. In general , concrete containing pozzolan

has improved workabil i ty, lower heat of hydratio

and a slower strength gain. When pozzolans are

be used, the required time to gain the design streng

may be increased beyond the standard 28 days fo

roads and streets and 90 days for airfield pavemen

to the extent that the concrete is not to be expose

to traffic.

c . C l a s s N p o z z o l a n s w i l l n o t g e n e r a l l y b


16/55

TM 5-822-7/AFM 88-6, Chap. 8

encountered in pavement construction. The use of

fly ash, however, is becoming increasingly common.

Fly ash produced by industrial burning of coal tends

to be highly variable, depending on factors such as

emission controls, load, and boiler design. This

production variability is compounded further by the

natural variability of lignite and subbituminous coal

that produce Class C pozzolan. Also, Class C

pozzolans have poor resistance to sulfate attack,

and some have high alkali contents that may contri-

bute to alkali aggregate reaction. Specifications for

pozzolans should require that the ASTM C 618

specification be modified to require a maximum loss

on ignition of 6 and 8 percent, respectively, for Class

F and N pozzolans and a minimum pozzolanic act iv i ty

index wit h lime of 900 psi at 7 day s. Mixture propor-

tioning studies should use the same pozzolans andcements that will be used on the project and must

determine that the f inal concrete characteristics ,

strength gain, and durabil i ty are adequate.

8. Miscellaneous materials.

a. Other materials used in concrete pavement

construction including curing materials, dowels, tie

bars, reinforcement, and expansion-joint filler are

covered by applicable specifications. When concrete

is required to be free of magnetic materials, special

instructions will be obtained from HQDA (DAEN-

ECE-G) for the selection of dowels, tie bars, and

reinforcement. Aluminum will not be used in concretepavements.

b. Field welding of crossing bars (tack welding) is

prohibited. All welded splices will conform to the

requirements of the American Welding Society (AWS)

D 1.4. Selection of the proper welding procedure

depends on the actual chemical composition of the

steel. A procedure suitable for one chemical compo-

sition can be t otally un suited for a nother composition

of the same strength grade. It is essential that the

composition of the steel to be welded be determined

before the welding procedure is established. Where

reinforcing bars are to be ordered for new work, the

fabricator should be informed that welded splices

are contemplated. The fabricator can provide the

chemical composition of the reinforcing bars and in

ma ny cases can provide bars t hat ar e more suited to

welding.

c. Epoxy-coated reinforcing steel and dowel bars

are being used more frequently in areas such as

bridge decks, coastal areas, and pavements subject

to heavy applications of de-icing salts to minimize

potential corrosion problems. If these materials are

used, they should conform to ASTM A 775. Epoxy-

coated dowels and reinforcing steel will rest on

epoxy-coated wire bar supports or on bar supports

made of dielectric material. Wire bar supports will

be coated for a minimum of 2 inches from the point

of contact with the epoxy-coated reinforcing bars.

Adequate ventilation to dissipate fumes must be

provided if epoxy-coated steel is welded.

d . Appendix C d e s c r i b e s t h e m a t e r i a l s a n d

methods used for the construction of steel fiber

reinforced concrete.

9. Water. Water for mixing concrete will be free frommaterials that af fect hydration of the cement.

Potable water may be used without testing however,

tests will be made in accordance with CRD-C 400 if

the water source is a stream or another body ofwater of unknown quali ty . Seawater has been used

successfully as mixing water, but this should only

be done if there is no feasible alterna tive. There ma y

be up to a 15 percent loss in ultimate strength, set

times may be affected, and surface efflorescence

may occur. The risk of steel corrosion maybe increased,

so the use of coated dowels and reinforcing steel

should be considered if seawater is to be used.

10. Sampling and testing of materials.

a. Cement. Cement to be used in pavements for

aircraf t traf f ic wil l be sampled and tested. Cement

meeting all other test requirements may be acceptedprior to the required 7-day age when the strength is

equal to or greater than the 7-day strength require-

ment. Cement for pavement projects requiring 1,600

cubic yards or less of concrete may be accepted on

the basis of the manufacturers certified mill test

reports showing compliance with cited cement

specifications.

b. Aggregates.

(l.) Listed sources.Listing of aggregate sources

will be based on a thorough investigation to determine

that suitable aggregates are obtainable for the

proposed use. Evaluation of the material will require

complete laboratory testing including petrographic

examinations, physical tests , durabil i ty tests , and

alkali-reactivity tests. The service record of aggre-

gates will be determined by inspecting structures

that have had exposure equivalent to the proposed

structure. When an aggregate source has been listed

previously for use on the basis of a complete investi-

gation, additional similar use of the source within a

period of 3 years may be permitted on the basis of

petrographic examinations and limited physical

12


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TM 5-822-7/AFM 88-6, Chap. 8

tests if t he results show n o cha nge in th e composition

and qual i ty of aggregate. For proper design and

preparat ion of pla ns an d speci f icat ions , i t i s

necessary to investigate and determine suitableaggregate sources and concrete strengths obtainable

with aggregates. I t is essential that these investiga-

tions be conducted a s ea rly a s possible during project

planning.

(2.) Sources for calibration hardstands. When

contract specifications cover the paving of calibration

hardstands, the list of sources will indicate which

sources are approved for such work.

(3.) Aggregate sources not previously listed.

When the contractor proposes aggregate from a

source not previously listed, the evaluation of

samples of that aggregate wil l include al l tests

necessary to demonstrate that a concrete producedfrom the materials wil l have qual i ty and strength

comparable with that of concrete made with aggre-

gate from the approved sources listed. When the

contracting officer i s respons i b l e fo r m i x ture

proportioning and cement is a separate pay item in

the contract , aggregates of good qual i ty that require

an increase in the quanti ty of cement over that

required by aggregates from listed sources to produce

concrete of the specified flexural strength will be

approved for use only if the contractor agrees in

wri t ing to pay for the addit ional cement required.

(4.) Unlisted source. When the con t rac t

specifications do not include a list of approvedaggregate sources, the source(s) proposed by the

contractor will be investigated as soon as possible

af ter the award of the contract .

(5.) Aggregates for a small project. Eval ua t i onof aggregates from non-listed sources and concrete

mixture proportioning for projects requiring 1,600

cubic yards or less of concrete, except for airfield

and heliport paving, wil l be performed by an approved

commercial test ing laboratory at no expense to the

Government.

11. Delivery and storage of materials.

a. Cement and pozzolan. Separate storage facil i t ieswill be provided for each type of cementitious

material . Storage faci l i ty wil l be thoroughly cleaned

before changing the type of cementitious material

stored ini t . Storage faci l i t ies must be weather-tight

and must be properly venti lated.

b. Aggregates.

(l.) Control of grading. Aggregate-handling and

aggregate-storage faci l i t ies may vary greatly for

different projects, and only general requirements

can be specified. Grading and uniformity of gradin

requirements wil l be determined as the aggregate

are del ivered to the mixer, and the contractor i

responsible for meeting these requirements. Carefuinspection of storage and handling operations

however, is desirable to assure satisfactory contro

of the aggregate grading and to prevent contamin

ation by foreign material . Aggregate storage tech

niques that use coned piles or spread truck-dumpe

a g g r e g a t e w i t h a b u l l d o z e r c a u s e s e g r e g a t i o

problems. Aggregates delivered by trucks are bes

dumped and left in individual adjacent piles. A clam

shell spreading aggregate in thin layers has als

been used to minimize segregation. Aggregat

should be handled as little as possible to minimiz

segregation. Potential sources of contaminant

i n c l u d e w i n d b l o w n f o u n d a t i o n a n d a d j a c e nmaterials and contaminants from equipment used i

handl ing the aggregates .

(2.) Moisture control. Uniformity of fremoisture in aggregate is essential for proper contro

of concrete consistency. A period of free-drainin

storage is required for fine aggregates and th

smaller size of coarse aggregate. Normally, 24 to 4

hours will be sufficient. However, shorter or longe

times may be specified if the tests of time to reac

an equilibrium so indicate.

12. Grade control. The lines and grades shown fo

each airfield and heliport pavement category of thcontract shal l be establ ished and maintained b

means of l ine and grade stakes placed at the jobsi t

by the contractor. Elevations of all benchmarks use

by the contractor for controlling pavement operation

at the jobsi te wil l be establ ished and maintained b

the Government. The finished pavement grade line

and elevations shown shal l be establ ished an

controlled at the jobsite in accordance with bench

ma rk elevations furnished by t he contra cting officer

The pavements shall be constructed to the thicknesse

and elevations indicated. Provisions for line an

grade control for roads, streets, and open storag

areas shall be included in the contract specifications

13. Proportioning.

a. Mixture proportioning. B efore a ny concrete i

p l a c e d , t r i a l m i x t u r e s w i l l b e p r e p a r e d w i t

materials from the sources to be used for productio

of concrete on the project. When the contractor i

responsible for mixture proportioning, trial mixture

will be prepared by a commercial testing laborator

approved by the contracting officer at no expense t

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TM 5-822-7/AFM 88-6, Chap. 8

the Government, and the results wil l be submitted

to the contracting officer for approval. When the

contracting officer i s respons i b l e fo r m i x ture

proportioning, trial mixtures will be prepared by the

Government wi th mater ials suppl ied by the contrac tor

from th e sources to be used for production of concrete

on the project. Mixtures will be made in sufficient

number to establish optimum proportions of the

aggregates and to represent a wide range in cement

contents and watercement rat ios within specified

requirements for air content and workabil i ty. The

water-cement ratio will not exceed 0.45 by weight

for pavement mixtures. After the final proportions

of the trial mixtures have been established, 6inch

by 6-inch cr oss-section test /bea m s pecimens f rom

each mixture wil l be made in accordance with

ASTM C 192 and tested as described in ASTM C 78.A minimum of nine test specimens should be made

to establ ish the flexural strength of each mixture at

each test age. From these mixture proportioning

studies, the control l ing maximum water-cement

rat io and hence the cement content required to

produce concrete of specified strength will be deter-

mined. This same procedure will be used to establish

new mixture proportions when necessary because of

a change in the source or the character of the concrete

ingredients after concrete placement has started.

b. Mixture proportions.

(l.) Contracting officer responsible for mixture

proportions. When the contracting officer is respon-sible for the mixture proportions, proportions of all

materials used in the concrete mixture wil l be as

directed. The contracting officer will require such

changes in the mixture proportions as necessary to

maintain the workabi l i ty , s t rength, and qual i ty

required by the contract specifications. The mixture

proportions determined by mixture proportioning

studies will be used in starting paving operations.

Adjustments will be made by the contracting officer

as necessary to establ ish the mixture proportions

best suited for job conditions and materials used.

Subsequent mixture adjustments wil l be made when

necessary, but usual ly t hese adjustments w il l be of aminor nature as required to compensate for variations

in gradings and the moisture content of the aggregate .

(2.) Contractor responsible for mixture propor-

tions. When the contractor is responsible for the

mixture proportions, proportions of al l materials used

in the concrete mixture will be as directed by the

contractor. The contractor will require such changes

in the mixture proportions as necessary to maintain

the workabil i ty, strength, and qual i ty required by

the con t rac t spec i f i c a t i ons . The m i x ture propor t i o

determined by mixture proportioning studies will be

used in starting paving operations. Adjustments

wil l be made by the contractor as necessary to

establish the mixture proportions best suited for the

job conditions and materials used. Project specifi-

cations wil l require the contractor to noti fy the

contracting officer prior to making any change to

the approved mixture proportions and to indicate

the changes to be made. Changes to the mixture

proportions wil l be of a minor nature as required to

compensate for variat ions in gradings and the

moisture content of the aggregate unless laboratory

mixture studies for the new mixture are submitted

for approval .

c. Workability. The concrete slump shall not exceed

2 inches. Within this maximum limit, the slump willbe maintained at the lowest practical value suitable

for prevailing weather conditions and for equipment

and methods used in placement of the concrete. For

small paved areas, slump in excess of 2 inches may

be permitted, but in no case will the slump exceed 3

inches. The concrete slump w ill be determined in th e

field by the method described in ASTM C 143. Slump

for slipform paving of airfield and heliport pavements

should be specified in a ra nge of O to 1 inches.

d. Strength. Control of the strength of the concrete

mixture will be based on tests of concrete specimens

taken during the paving operations. Pavements to

be used by aircraft are designed on the basis of theflexural strength that the concrete is expected to

attain at 90 days, and specimens wil l be tested at

this age for use in the evaluation pavements. Since

the period necessary to obtain the 90-day field

strengths is too great to exercise proper control of

the concrete during pavement construction, a 14-day

strength requirement wil l be included in th e contra ct

specifications. Flexural-strength tests will be made

at 14 days to determine compliance with the 14-day

strength requirement. In addit ion, 7-day strength

tests wil l be made to provide an early indication of

the concrete strength. The average strength at the

age of 14 days of any five consecutive individual testvalues representing each concrete mixture will be

not less than the specified strength at the age of 14

da ys, and not more than 20 percent of the individual

values will be less than the specified strength.

Adjustments of the concrete mixture proportions

wil l be made as necessary to maintain this strength

control. When sufficient 90-day strengths become

a vai la ble, further a djustment of the concrete mixture

may be made as necessary to assure that the 90-day

14


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TM 5-822-7/AFM 88-6, Chap. 8

strength used for t he design of the pavements wil l be

obtained and that an economical mixture is being used.

14. Subgrade, base, forms, and string lines.

a . Genera l . The sett ing a nd protection of forms ands t r i n g l i n e s a n d t h e f i n a l p r e p a r a t i o n o f t h e

subgrade, base course, or filter course require close

attention to al l detai ls to assure that the pavement

wil l have th e required thickness and the surface wil l

beat the required grade.

b. Subgrade. Subgrade is the natural soi l or fi l l

upon which the base and concrete pavement are placed.

Special procedures may be necessary when dealing

wit h frost-susceptible soils, expansive soils, pumping-

susceptible soils, lateritic soils, or organic soils.

Removing soft or troublesome soils that occur in

pockets may be desirable, where possible.

c. Base.A base m ay perform m an y functions, suchas drainage, construction platform, and structural

strengthening of the pavement. A base may be a

granular material or l ime, cement, or an asphalt-

stabilized material. Also a lean concrete, sometimes

referred to as Econocrete, is sometimes used as a

base. There is no clearly accepted definition, but

cement contents are typical ly lower, and sometimes

poorer quality aggregates are used. The lean concrete

base should meet the st rength and durabi l i ty require-

ments of cement-stabi l ized materials and can be

treated as a high-qual i ty stabi l ized material in

design.

d. Form materials. Steel forms wil l be used for al l

formed pavement const ruction. Wood forms genera lly

a re unsat isfactory for paving work, and t heir use wil l

not be permitted except for such miscellaneous areas

as bulkheads and curved fi l lets. To avoid the excessive

cost of pavement construction for small j ohs, wood

forms may be al lowed for pavements less than 8 inches

thick in noncrit ical areas, such as open storage areas,

helicopter parking pads, and vehicle parking.

e. Construction of forms. Provisions relat ing to

built-up forms may be omitted from contract specifi-

cations when the contra ct plan s require constant slab

depth for each paved area. When this provision isreta ined in a contra ct specificat ion, th e contra ctor is

required to furnish steel forms equal to the edge

thickness of the majority of pavement slabs for each

paved area. Built-up forms will be used only where

edge thicknesses exceed the basic form depth. The

base width of built-up forms will be equal to the

width required for a comparable full-depth form.

Side forms on sl.ipform pavers will be the full depth

of the pavement.

f. Placement of forms and string lines. Forms a

string lines should be installed well in advance

concrete paving operations so that the require

checks and necessary corrections can be ma

without stopping or hindering concrete placemenThe same reasoning applies to the final preparati

of the underlying material, which should not be le

than one full days operation of the paving equi

ment ahead of paving.

g. String line. The string line will be of hig

strength cord or wire. The choice will depend on t

type of automatically controlled slipform paver use

Certa in man ufacturers recommend tha t high-tensi

strength wire be stretched tautly between suppor

Other manufacturers recommend a large-diamet

cord and do not require the tautness that is recom

mended for the wire. The use of wire requires firm

anchored supports. As a result, the wire is less liketo be disturbed than is the cord whose supports

not have to be so firmly anchored. The wire

di fficult to see, and flagging should be at tach

between the supports to reduce the chance that

will be disturbed during construction. The cord do

not require supports to be as firmly anchored as f

the wire, and as a result , the cord is easier to inst

and maintain. However , the chance of sagging betwe

the supports is greater. The cord is easy to see, a

as a result, the chances of its being knocked out

al inement are less than for the wire. However, t

cord is more easi ly disturbed than the wire a

should be checked frequently.

h. Removal of forms. Pavement forms general

may be removed 12 hours after the concrete is place

A longer period will be necessary when the streng

gain of the concrete is retarded because of delayed

inadequate protection during cold weather. In som

insta nces, earl ier removal of forms ma ybe permitt

so that the transverse joints may be sawed complete

through to the edge of the slab without leaving

small fillet of concrete adjacent to the form.

15. Batching and mixing.

a. General . There are three types of plants: autmatic, semi-automatic, and manual . For pavi

projects, either automatic or semi-automatic plan

will be acceptable. Specifications will be prepared

al low ei ther type of plant , and the contractor w

have the option as to the type of plant to be used

b. Plant capacity. The capacity to be specified fthe batching plant and mixing equipment wil l

determined in accordance with the concrete-placeme

requirements for the project. Since the paveme


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TM 5-822-7/AFM 88-6, Chap. 8

slabs are comparatively small , the plant capaci ty

generally will not be influenced by any requirements

for maintaining the concrete in a plastic condition

during placement. The main considerations will be

the required placing schedule to meet the completiondate for the construction or, when slipform pavers

are used, the required amount of concrete to maintain

a uniform forwa rd m ovement of the paver of not less

than 2.5 feet per minute. However, the placement

rate specified for pavements constructed during hot

weather should also be considered in determining

plant capaci ty requirements.

c. Concrete mixers. Mixers ha ving a capa city of a tleast 5 cubic yards of mixed concrete are required for

airfield paving projects, but smaller mixers may be

permitted for small road projects and other small

miscellaneous construction. Contract specificationsfor jobs of suitable size and location will include an

option for the contractor to reduce mixing time during

progress of work from the mixing t ime required at

the start of the job on the basis of mixer performance

tests in accordance with CRD-C 55, provided the

fol lowing requirements are met at al l t imes:

Weight per cubic foot of mortar calculated to an air-free ba sis, lb/ft

3

Air content, volume percent of concrete

Slump, inches

Coarse aggregate content , portion by weight of each

sample retained on No. 4 sieve, percent

Average compressive strength at 7 days for each

sample based on a verage strength of al l test speci-

mens, percent 10.0

Water content, portion by weight of each sample

passing No. 4 sieve, percent 1.0

Parameters Tested For: Requirement, expressed as maximum permissible

ra nge in results of tests of samples ta ken from th ree

locations in the concrete batch

1.0

1. 0

1.0

6. 0

In addition, no reduction in mixing time will be

allowed if it results in a reduction in the 7-day

flexural strength from the average strength of f ive

consecutive sets of specimens made from batches

mixed the full time. The requirements for stationary

mixers and truck mixers will be included unless it is

determined that concrete complying with the specifi-

cations cannot be manufactured by these types of

m i x e r s . Truck m i xers o f t en have d i f f i cu l t y i n

discharging the comparatively low-slump concretemixtures required for airfield pavement construction,

therefore, truck mixers should comply with ASTM C

94. The tendency of the concrete to hang up in

discha rge chutes may cause delays, which frequently

lead to requests by the contractor that the concrete

slump be increased. This difficulty also may occur

with vehicles used for hauling concrete to forms

when stationary mixers are used. The slump of

ready-mix concrete will not be increased because of

16

the inadequacy of the mixing or transportat ion

equipment to mix and discharge the concrete.

d. Approval of mixers. Before truck mixers orstat ionary mixers are approved for use, careful

consideration will be given to the proposed plant and

faci l i t ies for storage and handling of materials, and

for batching, mixing, transporting, and handling of

concrete at the jobsite to assure that adequate control

of the concrete can be exercised. When truck mixers

ar e used with a long ha ul betw een the bat ching plant

and the project, adequate control of the concrete

may be di fficult due to variat ions in slump and air

content caused by differences in mixing time. In

such cases, i t wil l be necessary to require that mixing

be done after the mixer trucks arrive on the job.

Truck mixers will not be permitted for mixing concrete

on slipform construction. Truck mixers shall be

equipped with accurate revolution counters. In

general, truck mixers should only be used on jobs


21/55

TM 5-822-7/AFM 88-6, Chap. 8

requiring 2,500 cubic yards of concrete or less.

e. Transporting plant-mixed concrete. Vehicles fortransporting concrete from stat ionary mixers to the

forms will conform to the applicable requirements of

ASTM C 94. Plant-mixed concrete may be trans-ported in a truck agi ta tor, in a truck mixer operat ing

at agi tat ing speed, or in approved non-agitat ing

equipment. Non-agitat ing equipment wil l have

smooth, watert ight , metal bodies equipped with

gates to permit control of the discharge of the

concrete; covers will be provided for protecting

concrete in tra nsi t , a s required. Concrete tra nsported

in non-agitat ing equipment wil l be discharged into

the pavement forms or to the sl ipform paver within

45 minutes after introduction of the mixing water

and cement to the aggregates at the mixer. The

major problem in using ready-mixed concrete in

pavement construction is avoiding segregation indischarging and transferring the concrete from the

transporting unit to the final posi t ion in the form or

on the subgrade in front of the slipform paver. The

use of readymixed concrete requires suitable

t r a n s f e r a n d s p r e a d i n g e q u i p m e n t c a p a b l e o f

depositing and distributing the concrete in an

unsegregated condition in the final position in the

forms. When low-slump plant-mixed concrete is

transported, trucks equipped with vibrators are

often required to discharge the concrete and should

be required unless i t is sat isfactori ly demonstrated

that the concrete can be discharged without delay.

16. Placing.

a. General . Concrete may be placed between fixed

forms or using approved slipform paving equipment.

Both methods produce sat isfactory results, and

when possible, the option should be left with the

contractor as to the method to be used. With

slipform equipment, the rate of placement can be

significantly increased over the rate with fixed

forms. In addit ion, the material for forms and the

labor for sett ing forms are el iminated. As a result ,

the cost for large jobs will be less for slipform place-ment than for placement with fixed forms. However,

on sma ll jobs or larger jobs with special requirements,

the use of f ixed forms may be necessary or may be

more economical than the use of slipform equipment.

No guidelines can be given as to what size job will

permit the economic use of slipform pavers.

b. Placing time. Concrete will be placed before

obtaining i ts ini t ial set and within 45 minutes after

cement has been added to the batch. These provisions

apply to all paving projects regardless of the type

mixing equipment used. The addition of water to th

mixture in excess of that required by the mixtu

proportions to maintain slump during prolonge

mixing will not be permitted.c. Slipform paving. Approval of the sl ipform pavin

equipment for airfield pavement wil l be based on sati

factory performance in the field. Trial sections

sufficient length and located in low-volume aircra

traffic areas wil l be used to approve the paving equi

ment, considering both sl ipform and another for th

fill-in operation when scheduled by the contracto

Furthermore, approval shal l be based on the abi l i

of the machine to consolidate the concrete and for

the pavement to the desired cross sections. Pla

grade and surface smoothness tolerances must b

met. Pa rt icular at tention should be paid to the abi l i

of the machine to form the required edge withoexcessive slumping or tearing during slipform oper

tions and to form a suitable longitudinal constructio

joint during fill-in operations. The machine shall n

damage the surface or edge of the previously place

slab during fill-in operations. The suggested leng

of the trial section is 1,000 to 2,000 feet. Slipfor

pavers with a ful l-width auger are recommende

Traveling blades have been less sat isfactory. I f t

slipformed pavement is 10 inches or greater

thickness, some of the lighter slipform pavers m

have problems properly handling the low-slum

concrete.

d. Spreading. Hand spreading of concrete will

permitted only when necessi tated by odd widths

shapes of slabs, or in emergencies such as equipme

breakdown.

e. Vibration. Vibration requirements are influenc

by many factors, such as the type and size of aggr

gate, mixture proportions, air entrainment, slum

workabil i ty of mixture, and pavement thickne

The specified maximum spacing for vibrator un

and the specified vibrating procedures are based

field experience with the vibration of pavements

inches or more in thickness. There has been on

limited use of internal vibrat ion for thinner slabs.necessary for proper consolidation of the concrete

closer spacing of vibrator units will be require

Part icular at tention should be paid to vibrato

along the edge of the paving lane to ensure that t

edge is properly consolidated. General experien

has been that i t is more sat isfactory to use vibrato

at a closer spacing and for shorter periods of vibr

t ion than to at tempt to consolidate the concrete

prolonged vibration at a wider spacing. The durati


22/55

TM 5-822-7/AFM 88-6, Chap. 8

of the vibration will be limited by the time necessary

t o p r o d u c e a s a t i s f a c t o r y c o n s o l i d a t i o n o f t h e

concrete, and over-vibration will not be permitted.

Vibrators must not be permitted to touch forms,

dowels, tie bars, or other embedded items.f. Surface vibrators. Surfa ce vibrators w il l not be

permitted because past experience with them has

been general ly unsatisfactory. Surface vibrat ion

tends to bring excess fine material and water to the

surface, which in many instances contributes to

surface deteriorat ion and scal ing. Surface-vibrator

pans also tend to ride on high places in the concrete

surface and thus cause non-uniform consolidation of

the concrete.

g. Steel reinforcement. Project drawings wil l show

typical details of all slab reinforcement and will

indicate the pavements requiring reinforcement and

the location and amount of steel required in theslabs. This information will supplement the specifi-

cation requirements for reinforcement, and al l

requirements will be carefully checked to insure no

discrepancies between drawings and specification

requirements.

h. Placing during cold weather. Pavement concrete

should not be placed when the air temperature is

below 40 degrees F. If unusual job conditions require

construction at these low temperatures, special

provisions for placement and protection of the

concrete will be needed. For additional information

on winter concreting, refer to ACI 306R. The

necessary covers and other means of protecting the

concrete during cold weather should be available on

the job before starting concrete placement. Calcium

chloride as an admixture may be ei ther required or

approved to accelerate the setting time of concrete

placed during cold weather. No changes will be made

in the requirements for temperature of the concrete

when placing or for protection of the concrete

against freezing when calcium chloride or any other

accelerator is used.

i. Placing during hot weather. During hot weather

special precautions are necessary to prevent the

formation of plastic-shrinkage cracks which resultfrom an excessive loss of moisture from the concrete

before curing is begun. The concrete needs to be placed

at the coolest temperature pra cticable, and in no case

should the temperature of the concrete as placed

exceed 90 degrees F. Mixing and placing of concrete

will be controlled to keep moisture loss at a

minimum. Aggregates wil l be moist when added to

the mixer, and the subgrade da mpened so i t w il l not

absorb water from the concrete. The temperature of

the concrete may be reduced by using cement with a

lower temperature by sprinkling the stockpiles of

aggregate to produce cooling by evaporation, by pre-

cooking mixing water and by avoiding delays in mixingand placing concrete. The concrete needs to be placed

and finished as ra pidly a s practicable, and th e curing

sta rted w ithout delay. I f the a pplicat ion of the curing

medium should for any reason lag placement for a

t ime sufficient to permit surface drying, the surface

should be kept da mp with a fog spray, a nd placement

should be discontinued until corrective action can betaken. The fog spray equipment will be capable of

applying a very fine mist to the concrete to replace

moisture lost by evaporation. In windy areas,

screens may be needed to protect the concrete from

rapid evaporation caused by wind. Steps shal l be

taken to avoid an evaporation rate in excess of 0.2

pound per square foot per hour as shown in figure 1.

This is adequate for most conditions, but there are

reports of plastic-shrinkage cracking occurring

under adverse conditions when the indicated evapor-

ation rate was as low as 0.15 pound per square foot

per hour. Additional information is available in ACI

305R.

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TM 5-822-7/AFM 88-6, Chap. 8

Figure 1. Prediction of concrete rate of evaporation

( F r o m C u r i n g o f C o n c r e t e , C o n c r e t e I n f o r m a t i o n S h e e t ,

5.0

4.0

3.0a

I

2.0y

1.0

0

1 9 6 6 , w i t h p e r m i s s i o n o f t h e P o r t l a n d C e m e n t A s s o c i a t i o n ,

S k o k i e , I L . )


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TM 5-822-7/AFM 88-6, Chap. 8

j. Placing of small areas. For vehicular parking and

paving projects of 1,600 cubic yards or less, machine

spread ing, f inishing, a nd floating w il l not be required

if the benefits derived from the use of the equipment

are not commensurate with the cost of using the

STANDARD PRACTICE FOR CONCRETE PAVEMENTS

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Transcript of STANDARD PRACTICE FOR CONCRETE PAVEMENTS