. 4

4

4

4

4 4

4

4

Technical Report Documentation Page -_ --- -. -----__- 3 Recipient's Accession No

-- ----- -. ----I.- f 5 R1:port Date

1 Repcirt No

MN/RC - 97/19 4 Titlc and Subtitle

-- APPX,ICATION OF I3YNAMIC CONE 11 'ENETROMEI'EK TO MINNESOTA DEPARTMENT OF TMANSPOIR'TATION PAVIEMENT ASS133 SMENT PROC ED1.JR.ES

-----

-- ----I___---_ -.------.I--- --.___-- -*

7 Author(<) 8 Performing Orgamzation Report No

I 'r9PR3001 Thomas R. Rurnham

-_ -_-- -__--- -_ -.-- ----.--- ---I__- -. 9 Perforrmng Organization Name illid Addiess 10 Project/Ta:,k/Work lJnit No

Minnesota Department of Transportal ion Office of Minnesota Road Research 1400 Gervais Avenue Maplewood, Minnesota 55 109-2043

I 1. Contract (C) or Grant (G) No.

-----.------.I-----. --- ----- -- -. I3 'I ypc of Report and &:nod Covered t 12 Spc insonng Organization Name and Adtirev,

Minnesota Department of Transportation 395 John Ireland Boulevard Mail ,Stop 330 St. Paul, Minnesota 55155

I IFinaX Report

14. Sponsoring Agency Code

-_ -., -,---.._--,_-,.--_-- -,.,----------

16. Ab:#tract (Limit: 200 words)

The Minnesota Department of Transportation (Mn/DOT) began testing the dynamic cone penetrometer (DCP) in 199 1, finding the JXP an effective tool in the assessment of su1)surface pavement cortditions and strength. Researchers conducted extensive DCP testin); and research on both the Minnesota Road Research Project (MdROAD) ;and several pilot project sites in an effort to understand its useful applications in Minne?;oia.

M m O T currently specifies two applilcatioms of DCP testing in its pavement assessment procedure. One application involves using the DCP as a quality control device during the backfill compaction of pavement edge drain trenches. The second application involves i ts use in quality control of granular base layer compaction. This report details these applications and includes a copy of both specifications irn the appendices. Other lionspecified applications of the DCP have included investigations of soft subcut areas, determination of the condition of base a.nd subgrade matt::rials, under fill1 de:pth bituminous cracks, and monitoring of the effectiveness of subgrade flyash stabilization.

Researchers recently analyzed MdROAD projeci DCP test re!,ults to determine the limiting DPI value for each particular subgradl:: soil arid base type. The report presenfs recomirnended DPI limits

----- -- -. #----.---,.-,.--I-- .I---

Dynamic Cone irestrictions. C)ocument available from: National Technical Information Services, Sprin$ield, Virginia 22 16 1

-. -,

2 1. No. of Pages

37 -----

1'7. Dowment AnalysidDesciiptors

Paver nent Edge Drains Base Layer Compac,i:iom

California Bearing Ratio Subgrade Strength M*/IIOAD

----.- -,.-,.--_---.,I- 20. Security Class (this page)

IJdiis:;ified I 19. Security Class (this report)

CJnclrxssified -. -,------ -,--,.------.I--

A�~'l'IJIC2iTlI(3~N OF THE DYNAlVIIC CONE PEPlJIETlXOMETEI< TO

MINNESOTA Il1l~E~IE~ARTME NT OF TRANSPORTATION PAVEM1I:'NT' ASSESSXWIENT PROCEDURES

Final Report

]?repiired by

Thomas R. Burnham, P.E.

Mimx:sota Ilepartmvmt of Transportation (Iffice of Minnesota Road Research

1400 Germis Avenue Yblaplewood, MN 55109-204-3

May 1997

FZlblirihed: by

1Minnc:sota Departmient of Transportation Office of Resear c;b Administration 2,OO Ford Building Mail Stop 330

1 17 Univert sity Avenue St Paul Minnesota 55155

The contents of this report reflect the V ~ C W S of the autho,~ who i s responsilble for the facts and accuracy of the data presented herein. The contents do not nect:ssarily reflect the views or policies of the Minnesota Department of TI ansportation at the time of publicatron 'This report does not constitute a standard, specification, or regulation.

The author wishes 1 . 0 express appreciation to the Miniiesota Department of Transportation researchers, district matet ids engineers, and field personnel involved in DGP research since its inception in 1199 1. Special thanks go to the following people, who served on the DCP Research and Implemental ion Cornitnitlee:

Dave Beberg -. C;rading and Base Art Bolland - District 8 Materials George Cochran I C)ffic:e of Minnesota Woad Research Chuck Howe .- Geology Dave Johnson - Clffice of Research Atininis tration Joe Meade - District 6 Mcaterials Dave Rettner - Office of Minnesota Roml Research Duane Young ~ Pavernerrt Design

1I"BLE OF CXINTEIVTS

Introduction ............................................................................................ 1

Recent Mn/DOT DCP IR.esearclh ................................................................ 1

Limiting DPII: Values Based on Sail Type ................................................... 2

Current Application of 1:lhe DCI? by Mn/DOT ................................................ 4

Summary ............................................................................................... 5

References ............................................................................................ 6

Appendices Appendix A - Mn/lDCYI' Subsurface Drain Installation Specifications Appendix �3 - Mn/lDOT IBase Compaction Specificaition Based on DCP 'resting

Appendix C - MndlDCYI' IDGP Research H[isitory Appendix I) - Average PIPI Values far Tests Coindiicted Befort: Base Placement

(Trial Vwsion)

LLST OF TAIBLI1I:S AND Ii'IGURES

IJST 0 1 7 TABLES

'l'able 1 I>CP testing nsults after base coiirse placemen1 . . . . . . . . . ~. . ~ . . I . . . . . .~ ... . ___ . 7

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mn/ROAD Subgrade Soils, 5 year cells average DPI values after base course applied . ~ ~. . . . . . . . . . . . . . . . . . . . . . . . . . ".. . " ~. . . . ~. . . ~. . . . . . . " . . . . . . . . . . . . . . . 8 Mn/ROAD Subgradle Soils, 10 year cells avt:riige DPI values after base course applid ~. I . . . . . . . . . . . . . . . . . . . . . ~ ". . . ~ I ~. . ~. . ~. . . . . . . . . . . ~. . . . . . . . . . . . . . ~. 9 Mn/RQAD Select Granular Subgrade Soils, average DPI values after base course applied _. . .. . . . . .. . . . . . . . . . . .". . . . . ". . " " ~. . . . . . ~. . ~. .. . . .. . . . . . ~ .. . 10 Mn/RQAD It == 12 Subgrade Soil:,, average DE'I values after base course applied . . . I . . . ". . ~. . . . . . ~. . . . . . . . . . . . ~. ". . D.. . . . . . . . . ~. . . . ~. . . . . . . . D . 11 Mn/ROAD I K =I 12 Subgrade Soils, NIOLVR cell average D R values after base c m rse i~plplfied . . . . . . . . ~ . . . . ~. . . ~. . . ~. 1 " ...". . . . . ~. . . . . . . . . . . . . . ~. ~. . 12 Mn/RQ)AD 13ase M;iterials, Class 3 Slpecial average DPI 5 P3r 10 year mainline cells, . . ~. .. ~. ".. . . . . . . . . . ~ ~. . ~. . . ".. . . . . ~ ~ n.. . . " . . . . . . . . ~. ".. I . . . ~ 13 Mn/ROAI> Ihse Materials , Class 3 Special average DPI low volume road cells . . . . . . " . . . . . ~. . . ~. . . . . . . . ~" . . . n. ~. . ~ " . . . . . . . . . . . . . . . . . . . . . . " . . . . . . . 14 Relationship lietween the soil strength and remedial thickness of granular backi?ll/linte modificaticm ~. . . ~. ~. . . ~. . . . . y " ~. ~. ~ .. . . . . . . . ." ~. . . ~. . . . 15

Since its introduct L O ~ X to tlte Minnesota Deparlment 06 Transportation (MdDOT) in 1991,

the dynamic cone penetroirrieter (IIXP) has beexi found to be an effective tool in the assessment of

subsurface pavement condiitions and strength. Extensive IICP testing and research was conducted

on both the Minnesota Road Research Project (MirdROAD) and several pilot project sites in an

effort to understand its useful applicat~ons in Mimiesota.

Mn/DOT conducted many studnes attempting, to determine whether there is a reasonable

correlation between the IXP's; penetration incilex (DPI) and in-place conipaction density. Most

results of DCP testing on cxihesive and select grariular rnatcr nals showed too much variability tQ

practically apply a corr&tion. Research da:mcmstrated, however, that properly compacted

granular base materials exhibit very unifcirm I )PI values.

Over '700 DCP tests were conducted (PIP. the Mn/KOAD project during its construction.

I'est results were recently analyzed to determine ithe limil ing DPI value for each particular

subgrade soil and base type ~ Kecomended EIP1 limits are presented.

Mn/DOT currently specifies two differen1 applications of DCP testing in its pavement

assessment procedures. One appl ication inivolvcs using the DCP as a quality control device during

the backfill compaction of pavement edge drdn r.renches. Reports to date have indicated this

testing to be reliable and c:ffft:ctive in improvrng r.he compaction levels of these trenches. The

second specifled application off 1 )C:P testing iirxvolves its use in quality control of granular base

layer compaction. A copy of both specificatiorxs are included in the appendices.

Other nonspecified appll ic atrons of the 119CP by MrdDOT have included investigations of

soft subcut areas, determiiriatioin of the conditrsn of the base and subgrade materials under full

depth bihiminsus cracks and monitoring ithe effectiveness of subgrade flyash stabilization. The

T'CP has also been used lo measure the foundation strength of footing pads for a maintenance

building.

Through extensive resem:h, several pavement asessment applications have been

discovered for the DCP. 'The uliliization of this simple and inexpensive tool should provide long

lasting benefits to newly construn. ted and rehabilitated pavements throughout Minnesota.

I ntroducth

Since its introduction to the Minnesota Department of ‘Transportation (Mn/DOT) in 1991

the dynamic cone pt:netrorm:ter (Yl)(:P) has beeiti found to be an effective tool in the assessment of

subsurface pavement conditions and strength. Extensive DCI’ testing and research was conducted

o n both the Minnesota Rtsiid Reqearch Project (MdROAD) and several pilot project sites in an

effort to understand its useful applications in Minnesota.

An important par1 of arny research is the xmplementation of its successful aspects. As

rlecommended by the Mn/I:)OT IDiCP Research and hiplementation Committee , this report was put

together to summarize the inqkmented ,aspects of the I>GP in Mn/DO’T pavement assessment

procedures. A DCP research hisaory arid a smunary of recent research findings is also presented.

Recent MdDOT DCP Rt:search

Historically, Mn/I>BIT ha:-, monitored the compaction levels of pavement subgrade and base

layers by means of in-place density testing. As a result of Ihis, many studies were conducted to

determine whether there is a reasonable c orrelatioln between the DCP’s penetration index (DPI)

and in-place compaction density Most results of DCP testing on cohesive and select granular

materials showed too much variability to practically apply a correlation. Research demonstrated,

however , that properly compacted granular base materials exhibit very uniform DPI values.

The most recent rtxarchi focused on whether a limxting DE’I value, one that will ensure

aldequate compaction 1evt:ls tirirrng ~on~1ructiisn, can be determined for some of the standard

Mn/DOT granular base (~mianixfac:i~ired) nnater ials ‘Through statewide field testing on granular

base layers deemed adequately compacted by exnsting test methods, it was discovered that a

limiting DPI could be deitermxnied. The results of that study allowed the creation of a granular

base layer coinpaclion DC:P test procedure (to1 be described later in this report). The long term

implementation goal of than procedure is the rethiction or elimination of the time consuming sand

cone density testing method.

During past I X P testing rwarch on select granular materials, it was found that due to lack

of confinement near the SLLI’CX~, IDPI values were not valid until several inches below the testing

surface. To assess whlether tlhis same behavior. occurred in granular base materials, an

I

e Kperimental steel plate was fabricated to test whether imposed confinement would provide more

accurate DPI values closer to the surface. Thr: plate (300 r m i diameter, 20 mm thick, 28.6 rrmn

dia. center hole) was used at several projects during the 1906 construction season, and showed

little effect 011 the confinement 1t:vt:l near the surfaw. Based on results from that testing, it was

shown that the granular bast: materials used in Mimesotii do not experience much loss of

confinement inear the surface when properly compacted. This information provided confidence

that the granular base lay t:r coimpact ion spea:ific:ation could be developed without requiring

imposed surface confinement diiir ing DCF' testing.

The DCP was origirnaXlly designed to be u w d as a tool for the assessment of pavement

conditions and layer thickiric:c:sses in n-ehabiliitatioxi studies. This application of the tool has , up until

this point, been underutilx2:n:d by MdDOT. The main reason for his has been the lack of DPI

values which can be used for strength comparison. On recornmendation of the DCP committee,

1:CP test results from thie M[m/lWAD projecl were: assembled and analyzed to determine the

presence of reasonable 1iIinLting; 1)PI values. The results of this analysis are outlined in the next

section.

For hrther information, a chronology off Mn/Z)O'I' DCP research can be found in

Appendix C.

- Limiting DPI values based on soiil type

Over '700 DCP tests wt:rc conducted cm the Mn/RC)AD project during its construction.

Tests were conducted on subgradc:, subbase, and base layers as they were constructed. Those test

rcsults were recently analyzed to determiine the limiting 111'1 value for each particular subgrade

soil and base type. 'The test rcsults were allso ;~~~illyztA to determine the effect base course

application had on previoiuslly tesitetl subgrade layers (confiriement effects).

The following genei-a1 observations were made duiri~ig the analysis:

1) Identifiable DPI limits could be dletennxned for the Mn/ROAD silty/clay subgrade, select

granular subgrade, and class 3 ,special gradation granular base material

2) The effect of ccurfinement from an overlyiing granular base 1ayt:r could clearly

be seen during 1 lbe analysis of pavemeniL sections with select granular subgrade

2

3) The layer thicki-nc=sses of Mn/ROAD class 4 special, class 5 special, and class 6 special

gradation matexids wax: inadequatc: to establish a reliable DPX limit value.

Table 1 summarizcs IS thc h/Irn/ROAD D( 'I) rcsults from tests conducted just prior to paving

the various surfaces. Each sox1 and base type was divided into test cell lype (5 year design life,

10 year design life, low volwnit: road design), khen into 300 rnm (12") layers, and finally analyzed

lor its average 11H. Figures 1-7 depict the analys;is results with the recommended DPI limit

indicated by the bold horizon~all line. Appendix D contains figures generated from DCP tests

( onducted before the granular lb; ist: layers were constructed.

Based on the analysis of Mn/llO)AD DCP testing, the following DPI limit values are

recommended for use by a soils engineer when anallyzing IICP test results conducted during a

rehabilitation study: n:im blow

Silty/clay material -W DPI <: 25

mm inches Select granular ma1t:rkal -+ DPI <:: 7 -- blow

rnm blow

MdROAD Class 3 Spt:c:inl gradation materials -* IIPI <:: 5

These rtxommended va1i.m assiunne adequatv confinement near the testing surface ~ If these

recommended limits are exceedec 1 during ii rehabil \tation study , addition soil testing methods are

recommended.

Special notice should be given in that the above values were determined independent of

moisture content effects. h4oxsiture effects are many times responsible foi the great variability in

I)CP test results. However, as the figures show, a limiting value for each soil type is recognized.

l o further test whether the reconmended limil ing UP1 values for subgrade soils are reasonable,

the values were correlated 1 o CBIR (Cali~fornia Bearing Ratio) and compared to the constructibility

limits as recommended b.y the llllinois Ilepartuient of Transportation (IDQT). Figure 8 shows a

graph presented in [DOT":; Sup?;:rade SttxbiZi[y Mtznual [2] which indicates minimum subgrade

( 'BK values below which subgxade treatment IIS recommemdt:d. Using the DPI-CBR correlation

a?; suggested by the 1J.S. Army Corps of Engirieers (Waterways Experiment Station) 131 : 292 CBRz __--

DPI 1 1%

the silty/clay recommended DP1[ limit of 25~mmllblow correlates to a CBR of 8. A field (unsoaked)

CBR value of 8 correspomls to the subgrade coir~ect ion cutoff point on Figure 8. For CBR values

above 8 subgrade improvernerit is usu,slly not necessary. This simple exercise provide:;

confidence in the recommended IDPI limit for I;ilty/cKay subgrade soils.

___ Current application of the IICP by Mn/D(3T

MnIDOT currently specilies two different applications of DCP testing in its pavement

assessment procedures. One application involves us ing the DClP as a quality control device during

tbe backfill compaction of pavcmnent edge drain trenches[ 11. This application was devised to

reduce settlements of bituminous shoulders near the pavemerit edge.

The specific test procetiurc: for edge dram trmch testing is described in Mn/DOT’s Special

Provisions SP5-128. The

procedure is essentially as fi~llow:~: fjhoflly afteir installation of the pavement edge drain pipe and

fine filter aggregate backfill rnatcria17 IICP testing is conducted to insure the penetration index

(1)PI) is less than 75 rmn pcr blow (3 inches per blow). Each 150 mm (6 inches) of compacted

backfill material is tested fi2r compliance. Reports to this date have indicated this testing to be

reliable and effective in irnprovirrg the cornpacr ion levels of these tuenches.

A copy of this special provision can be found in Appendix A.

The second specified application of DCP lesting involves its use in quality control of

gaanular base layer compaction. This application was devised to reduce Resting time and effort,

while providing more consistent quality contro 1. of base layer compaction.

The specific test prc~cedmre for granular base layer comnjpactiorn is described in the Mn/DOT

(trial) specification 221 1.3 .G4 I ,4 copy of thil; trial specification can be found in Appendix B

The procedure for this type of itestrng is as follows: following the compaction of each layer of

gJanular base material, DCP tests are conducted to mure the penetration index (DPI) is less than

19 mm per blow (0.75 inches per blow) This DPI limit value is valid for all freshly compacted

4

ibranular base materials. Mumt:rt us field tests have shown the DPI dramatically decreases as the

blase materials “set up” over timr~~ and undler loading from traffic.

At this time, the trial specification only allows DCP testing to “pass” adequately compacted

p,ranular base layers. Tesl failurtis must be condimled by testing using the standard Mn/DOT sand

cone density test method (iiiodnfxed AASI-ITO T 191).

Other nonspecified applic:at ions of the DCIP by Mn/L)Q)T have included investigations of

soft subcut areas, detenriination of the clondition of the base and subgrade materials under full

tl epth bituminous cracks, arid nncmj toring the effectiveness of subgrade flyash stabilization. The

1)CP has also been used to mirsitrt: the foundation strength (of footing pads being constructed for

a maintenance building.

Summary

Through extensive research conducted by the Office of Minnesota Road Research, several

pavement assessment appl icatioins have been tlisu)vered for the dynamic cone penetrometer.

Simple and inexpensive irc design and operation, the IDCP proves to be a versatile tool in pavement

condition analysis and desjgn. ‘Tlhe application of I:KP testing in the quality control of edge drain

trench and granular base layex- compaction should provide long lasting benefits to newly

constructed and rehabilitated pa\ ernents in Minnesota.

1. Ford, R.G. and Eliason, 113. E.. “C~:)mp;irison of Compaction Methods in Narrow

Subsurface Plrainage I’rerlches, ” Paper presented at ‘TKB 72nd Annual Meeting,

January 1993, Washington, D.G.

“Subgrade Stabililty Manual, ” Illinois Department sf Tramportation, Policy Mat-10,

1982.

Webster, S.L., GriilJ, R I [ . , and Vv‘illiarns, ‘T.P., “Description and Application o f Dual

Mass Ilynamic Ccme E)em:trometr:r, ” U SAE Waterways Experiment Station,

Vicksburg, MS, M d y 1992.

2.

3 .

6

Table 1 I ICP testing results after base course placennenf

North 1,ovv Volume

Material Type

Clay/silt

15.0 (6.'71) 19.0 (6.95) 25.0 (11.44)

Clay/silt

5 (1.30)

3.2, (0.50)

-- - .-_- ~ I 5 (1.61)

.-I,-----,,, .---._- 4.0 (1.62)

4.2 (0.93)

rn=u--Ui 11-

Clay/silt

6 (2.02)

3.1 (0.31)

Clay/silt

Sand

Class 3 Special

Class 3 SDecial

10 year 14 0 (5.57) 18.0 (5.24) 16.0 (4.97)

South Low 1 112 0 (5.48) 1 20.0 (6.95) t- 15.0 (6.87) Volume

-____-_- - .-_--____--.

7

1

I i I 1 , I I

70 1 I

I

Mn/ROAD SUBGRADE SOILS

I

10-YEAR CELL AVERAGE DPI VALUES AFTER BASE COURSE APPLIED

I ~

=in i V

0 1 16000 1 18000 120000 122000 124QQO

STATION LOCATION 0 0-300 mm depth 300-600 mm depth A 600-900 mm depth

Figure 2

30

j I I I

1 I I I I

t u

I I , I I I I I

I I I I I I I

U

pJ c" g 10

I I

> a 5

I 1 I I I I I I !

0

1

Mn/ROAD SELECT GRANULAR SUBGRADE SOILS

1 I

AVERAGE DPI VALUES AFTER BASE COURSE APPLIED

I

I I

I I I I ! I I i

I - - - - - -

15500 16000 16500 17000 17500 18000 18500 19000 19500 Note: 10000 added to actual station for this area

(for better graph) , STATION

0 0-300 mm depth m 300-600 mm depth A 600-900 mm depth Figure 3

70

60 A

3

Mn/ROAD R 4 2 SUBGRADE SOILS SOLVR CELL AVERAGE DPI

VALUES AFTER BASE COURSE APPLIED

16000 17000 18000 19000 . STAT1 0 N

20000

0 0-300 mm depth rn 300-600 mm depth A 600-900 mm depth Figure 4

21000

Mn/ROAD R=l2 SUBGRADE SOILS

I i I I I

I I

60 I I

~ i j I 1 I I j j j j i 1

I i I I ! I I i

- I I 1 I I I

I a. i j

N 0 I l V l S ' OBBPZC OOOZZC OOOOZC 0008CC 0009bC OOOPCC OOOZCC OOOOCC

I I

I

I i I I

, I

OE

Mn/ROAD BASE MATERIALS CLASS 3 SPECIAL AVERAGE DPI

LOW VOLUME ROAD CELLS

19000 19200 19400 19600 19800 20000 20200 20400 20600 . STATION

0 0-300 mm depth Figure 7

n

E E M

- m

W n

0 I I-

-

4l4 ol

RELATIONSHIP BETWEEN THE SOIL STRENGTH AND REMEDIAL THICKNESS OF GRANULAR BACKFILL I LIME MODIFICATION [2]

APPE,NDI[X A

Mn/DOT SUBSIIRIF'A CIE DRAIN l[NSrI'ALLAIUON SPECIFICATIONS

SPECIAL PROVIL!IOI1.'S SPS-IL'M.: REV. 11/21/96

-.__- S P!S- 1 Z! 8 S- (2 502 ) S lJ.IiE-.?J IR FA@ Ef D RAI IN S . PAVE M E NT E D G E D RA I N

-____ TYPE This work shall consist of constructing 3-inch diameter edge drains in

accordance with the applic:ablc? provisioi7s of Mn.lDOT 2!302, the Plan and these Special Provisions. This drain is iri.terrded to collect and discharge water infikrating into the pavement system from r;iin or snow melt, and sprkng-thaw seepage.

s-. 1

Efdge drain pipe shall be perforated Corrugated Polyethylene (PE) Tubing, Mn/DOT 3278. To prevent: infiltration of fine filter aggregate into the perforated pip'e, it shall be wrapped with gi:i?otextile, MniCIO'T 3733, Type I. Trench backfill shall be Fine Filter Aggregate, Mn/DC)'T 3149.%J, which i s modified so that the percent passing the No. 40 sieve will be 5-35.

s-. :2 Construct ion R t q 11 ire me n k

A. been constructed to prevent damage to the drain and/or discharge pipe by truck hauling. (See paralgraph 5.4. below.) Drains shall be placed by machine trencher capable of cutting the trench an'rl laying ,the pipe in a continuous operation. Plowinig will riot: be permitkd. The trenching equipment shall be so designed and operated t~hat excavated mat:erial does not fall back into the trench. A self-leveling trenching machine shall be used if the off-set between trackdtires of the trencher is greater .I:t-iaril 6 inches. Trench width shall be 6-inch minimum, 10-inch maximum. f3otton.i of the trench shall be shaped to cradle lower one-third of the pipe., Laser griiiiitle control vvill be required whenever pipe grades do not follow pavernerit grades at a c0nstan.t depth.

Drains adjaicenl: ,to new pavement::; shall be placed after the pavement has

B. IJ n I e s s otherwise spec ifi eld :

1. 1 he edge drain $;hall be iristalltd prior to pavement cracking.

Where ir-i place FJCC pavervient is to be cracked prior to overlay,

1- '2 . Drairirs plac.::ed in conjunction ,with pavement widening shall be placed prior to excavating the widening-trench. A "feeler gage" on the trenching nwchinc? shall be used to insure that the pipe is accurately located at the design distance from the edge of the in place pavement. After compaction, the filter agclregiate in the drain shall extend at least 4 inches above t h e bottom of the trench to be cut for widening.

A-- 1

3. trenching head shall run tight agairist the pavement so as to completely excavate a11 adjacent soil. Ttie Engineer may direct that any soil not so excavated, tie removed prior to placing any filter aggregate, or repaired if discovered later, and, all at the Contractor's expense.

Whien the drain is being pllaced next to a PCC pavement, the

4. When the drain is being placed next to a new hituminous pavement, it shall be constructed after all the baselleveling courses are in place, but k)efcani the wearing coi.irse is placed. to avoid damage to the finished pavement. For both nevv and rdrofit construction, the trenching head shall contiriuously intercept and cut-off the roll-over portion of at least the lower bituminous course. This will provide a positive connection for water Ilow from thc;rmal cracks into the drain. The trenching spoils shall always st-iow evidence of bituminous materials. Any spoils on the pavement: shall be totally cleariecj-off prior to placing the wearing course for new pavement:; or the first bit:uminous lift for overlays, and to the satisfacticin of thje En<gineer.

5. placemeni, the biturninous shall be coultered, sawed, milled, (or other approved rnethod), to leave ;.I srrrooth edge and prevent disturbance to the bitumirious to remain in placf:.

When a bituminous shoulder is to rernain in pliace after drain

6. place prior to .trenching, except: that for biturninous pavements, aggregate need only be in place to the Iieight of the adjacent lift at the time of t re n c: h i n g .

For new c;onstnx:i:ion, the shoulder aggregatelbase must be in

7. 0.2'/;, and outlc:ts; to the ditch shall be at a maximum spacing of 500 feet and at low ~poirits as sho'wn iri the Plan.

Unlel:js othenivise specified, drain grades shall not be less than

C. or in a separate operation which will immediately follow the t.renching activity. If the pipe and filter aggregate are not placed simultaneously by the trenching machine, the Contractor shall irisurt! that the pipe is properly aligned in the shaped cradle before placing the ernclosing filter aggregate. No shield will be required on the trenching head unless the soil type or Contractor's operations lead to sloughing #or ca,nirig from e i t l w side of the trench, in which case the Engineer will direct that a shield be used and that the filter aggregate be placed within the shield. All excavated trench material shall be disposed of off the Right of Way unless other uses are approved by the E!ngineer.

The .filter ;aggregate backfill rriay be placed simultaneously with the pipe

A-2

D. permit satisfactory cornpaction. (Typically 3-5 percent by weight.) Filter aggregate shall be corripactetl b y equiprnent which can achieve a minimum compacted density o f $15 percent of rnaxirnum standard Prodor for the full depth of the trench. (Maximum standard Proctor density is approximately 1 10-1 20 pound:; per cubic .foo.t for Fine F-iilter Aggregate.)

Filter aggre<;li3te shall be free-flowing, but with adequate moisture to

Prior ‘l:o beginning of the routirie trenching and backfilling operation, the Contractor shall cc)rist:wct at least a 50 foot long .test trench on the project using the same compacAion depths, trench backfill, compactor, etc. as will be used for the project work. Adequacy of compaction in the test trench will be evaluated using a Mn/DOT- supplied Oyriamic Conte Penetrometer (DCP), details for which are on file in the Fiesearch Section, I::>.ffic:e of Materials Research and Engineering. Arrangemc~nts for DCF) testing must be done through the Engineer, and at least two days of lead-1:irrre mwst be provided.

Penetration r,esis,tances of three (.3) inches or less per DCP hammer blow will indicate satisfactory compaction. Compliance will be based on the average of three DCP readings for similar depths in three tests taken 10 feet apart. Unless otherwise directed by the Engineer, penetration readings will be started from the point where tl-1~3 DCF’ equipment stabilizes after being carefully set in the trench.

No more than 24 inches of filter agcgregattrt may be compacted in any one lift. Uriless approvl3.d tiy the ES.ngineer, depending on equipment type, smaller lifts or more than m e pass of t:he compactor may be required to achieve satisfactory densii:y throughout the compacted depth. CJnless otherwise approved by the EEngineer based on IDCP testing, the compactor shall not travel at a ra.te grea,ter than 60 feet per minute. If the compaction method or source of trench backfill changes, or for any reason the Erigirieer is not satisfied with the compaction provided, the .trenching operat:ion will be stopped until additional DCP testing is per-forrrie’d and any nc:icessary cmrections have been made. (Up to two days l e a d - h e may be required for DCP re4estirig.) Additional co m pact i o n w i I I b 1:: req u ired w ti e n D C:: I’ t iss; t i n g i n d i ca tes i n s u ff icie n t density . After compaction and m y necessary leveling, the filter aggregate shall extend up onto the adjact.int pavement to the extent shown in the Plan typical section. I

E. Where the filter aggrecgate trench, as required by the Plan, is to be capped by another ,type of granular r’naterial or bituminous mixture, these materials shall be placed and compactel:i separately from the filter aggregate and not as part of any similar rnateriail tcl be placed in a future operation. Bituminous caps shall tie heaped at least one-inch and rolled; granular caps

A -3

S-.3

shall be placed at least one-inch high (itid receive vibratory cornpaction to the satisfaction of the E iit!gineclr. Placement o / these caps will provide support for overlying materials arid al!;o incorporate a second compaction effort in the trench.

F. Contamination of the filter aggrrii:xgate will not be permitted. Aggregates and/or o.ther soils shall rio,l: be deposited or mixed on the adjoining concrete or bituminous pavernenl.. Arty rriaterial spilled on the pavement surface shall be removed by sweepiimg.

Once the drain and discharge pipe are in place, no construction equipment will be a.IlNowed to traverse ,the drain o r discharge pipe until the system is properly protected (covered) to .the satisfaction of the Engineer. The drain shall remain open and operative after installation so that water does not c.ollect in the pipe.

-_____ Measu re m e 1.11 a r~ d Pavrri - en t

lVleasuremeril will be made by the length of furnished and satisfactorily installed Subs~irface Drain, Pavement Efdge Drain Type, approved by the Engineer. Payment will be made under I tern 2502.!541 (3" Perforated PE Pipe Drain) at the Contract bid price per linear foot which shall be .full compensation for trenching, fabric wrapped PE pipe and installatior 1, aggregate backfill, cap, cornpaction, and all other associated work.

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AiPPENDIX B

Mn/lDOT IB,QSE COMPACTION SPECIFICATION BASED ON IDCP ‘I’ESTING

(TRIAL VEIRSION)

The following information outlines the Mn/DOT granular base material compaction specifications based on D W testiing. This method of compaction quality control testing was fjrst made available for the 1997 construction season.

F"netration Index Method (Trial Mxl/lDOT Specification 22,11.3C4)

The full thickness of' each layer shall be compacted to achieve a penetration index value lcss tlhan or equal to 19mrn pew blow, as detennined by a M[n/DOT standard dynamic cone penetrometer (DCP) device compacted thickness but a testiiny, layer cam be inci eased in thickness to a maximum of 150mm if compacted in one lift by ii vibratory roller. At least two dynamic cone penetrometer tests shall be conducted at selected sites within each 800 cubic nneters(CV) of constructed base course.

alternatively retested and accepted if meeting 1he criteria of the Specified Density Method 221 1.3C1.

Water shall be app11ic:d to the base material during the mixing, spreading and compacting operations wheri axid in quantities dhe Engineer considers necessary for proper compaction.

K+on test purpose.,, a layer will be considered to be 75mm in

Compacted areas with a penetriltion index 1:rt:ater than 19mm per blow may be

Dbeterminat ion of Penetraltion I[ndex Value

The penetration index v,due will lbe detaxmmed usiirng a Mn/DOT standard dynamic cone penetrometer (DCP) device. 'The basic text niethod and detailed test procedure can be found in the Mn/DOT User Guide to the Dynamic Cone Penetrometer.

DICE' Test Procedure for C:ompi.tction Quality ( h t rol of Granular 13ase Materials

1 Locate a level, undisturbed arca. 2 Place DCP device on the: base aggregate and liglbtlly seat the conc tip by tapping the anvil

with the hammer. If seating process or self weight of device causes initial penetration exceeding %Omm, relocate tesl to a site at least : iOOrnm from previous test location and reseat cone. If second site fails the above criteria, cornpaction is not acceptable and the area being tested must be recomp,acted.

3. Record penetration measurexiient from seatirig using the graduated rule on the DCP. 4. Carefully raise the hammer riinitil il meets thi: handle, then releasc the hammer under its own

weight. Repeat the process three more times for a total of four drops of the hammer. 5 Record final penetratioiri measurement from the graduated rule on the I X P . 6 Subtract measurement in step 3 from measuremcnl in step 5 and then divide the difference

of the measurements by four If the resultirig, vithie is 19mm or less, the test passes.

APPIWD IX c Mn/DOT DYNAIMJC IKSONIZ 1PENE:TR~DMETEIR RESEARCH HISTORY

MmlDOr IXP Research History

The following is a brief' history of dynamic cone penetrometer (DCP) research conducted by the Minnesot i i Department of Transportation i(Mn/DOT).

1'391 : - Idea of using DCIP on Ntn/KOAI> project introduced by Matt Witczak. - Prototype DCP fabricatcd by Maplewood shop lbiised on plans obtained from

- DCP testing begins OWJ PJIrdROAD mainline subgrade layer. - DCP research pilot projects concfucteni in Becker, Sacred Heart, and Faribault,

Illinois DOT.

Minnesota.

1992: - Mn/lDOT Geotec:Xinica 1 section performs research iind analysis on using the DCP for

- New edge drain c:ompaction spec ification based on DCP tcsting is formulated. - DCP testing conitinues a t Mn/ROAD o n subgrade and base layers. Large subgrade

- Design and developmmit of an automated dynamic cone pcnetrometer (ADCP) begins. - Laboratory expeir~~inneinits begin iin effort to determine correlation of penetration index

monitoring edge d r aiiri trench compaction ]levels ~

void in test cell 2'3 found during DCID tesl.ing.

(DPI) to compactjon dei isity for subgrade rnateria1,s.

1993: - Edge drain trench c:oni~paction specifi6:atioln based on DCP is adopted. - 15 DCPs are fabricated by machine shop in Illinois for distribution throughout

- DCP training course dkvel oped and condi icted for district personnel. -- Users Guide for tXx: Dgri iamic (lone Femet rometer developcd and distributed. - ADCP delivered, ksted, and accepted by ILl[n/DO'T. - Comprehensive lic eratiiare search and inves tigatioin conducted to research current DPI

Mn/DOT districts

correlations utilized w o ~ Idwide.

1094 : - Extensive subgrade ALN :l? testing on Highway 59 near Marshall, Minnesota conducted in continued cffort to develop correlation of DPI to compaction density. Project construction inspector also conducted side lby side DCP and sand cone density tests throughout st:ason

19195: - Highway 59 data analyzcd. Conclusicm that there i s not a reasonable correlation of DPI to compaction dexrsiity for fine grainecl soils. Empirical DPI limits are developed based on general soil types.

- DCP used in Mdli!OAD test cell 33 rrittirig investigation. - DCP used to evaluate fly ash subgrade statdization.

c- 1

1996: - DCF' research con~~ucterl towards developing empirical DPI limits for base layer compaction during construction. Spt.cific:at ion developed based on results of testing several sites throughout the state.

- Problems with edge tlra in trench compaction specifications noticed. Introduced proposed changes to iwting procedure to insure intended results.

- Comprehensive IJser Guide to the Dynanliic Cone Pmetrometer brochure developed for widespread clistribut ion. Contains test procedure, correlations, and plans for fabrication of a IDCP.

1'997: - DCP brochure is highllij ;hted in several national publications. DCP information

- Base layer compaction specification base(! on DCY testing is adopted and will be

- DCP training video to be produced.

inquiry has increased significantly .

utilized on several projects during 199'7 construction season.

Several reports and artic1t:s have been written throughout. the research process.

Fublished reports:

May 1993 : 93-05 In Situ Foundation Characterization Using the Dynamic Cone Penelromeler (Bunnham and Johnson)

Fall 1996: User Guide to the Dynamic Cone Penetromezer (MdROAD brochure)

Unpublished reports:

July 1991 : The 1C)ynanric Cone Penetrometer ~ A :Surnmaxy Outlining Its Characteristics and Uses As 'They May Relate to the Mn/ROAD Research Project

Nlovernber 1991 : Use of the Dynamic Cone Penetrometer in Evaluating Subgrade and Base Material at the Becker Pilot Project

Deceniber 1991: Use of the Il>ynarnic Cone Penetrometer in thr: Subgrade Evaluation of TH-2 12 Near Sacred Heart, Ilvlinnesota

January 1992 : Use of the 1)ynamic Cone Penetromeier in the Subgrade Evaluation of 1-35 Near Faribault, Minnesota

April 1993 : Users Guidc..: for the Dyninmic: Clone Penetrometer

Spring 1995: Mn/EZOAD Test Cell 33 Rut Iiivestigatxon

July 199s: Hwy 59 IXJP Correlation Study

August 1996: Applical.iori of the Dynamic Cone Penetrometer to Mn/DQT’s Pavement Asserssnienit E’rocedures (Revised Dra ft)

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APPENDIX D

AVERAGE: DPI VALUIES FOR TESTS CONIDUCTEI) BEFORE EASE PLACEMENT

70

60

0

Mn/ROAD SUBGRADE SOILS 5-YEAR CELL AVERAGE DPI

VALUES BEFORE BASE COURSE APPLIED

1 1 QQQQ 111Q00 I 12000 1 13000 114000 ~ STATION

1 15000 1 16008

0 0-300 rnm depth 300-600 mm depth A 600-900 mm depth Figure D-I

60 i

0

I I

I I

I I 1 1 I I I I I

I ! I I I

VA

Mn/ROAD SUBGRADE SO!LS IQ-YEAR CELL AVERAGE DPI

-UES BEFORE BASE COURSE APPLIED

1 16000 1 18000 120000 122000 . STATION

124000

0 0-300 mm depth 300-600 mm depth A 600-900 mm depth Figure D-2

W w

I

1 1 I I I I I I I I I I I

j I I I I I I I I I I I

I I

I 1 I I I

I I I I

I

70

68

10

0

Mn/ROAD SUBGRADE SOILS SOLVR CELL AVERAGE DPI

VALUES BEFORE BASE COURSE APPL!EB

I I I I I I I I I I

I i i I I

i i i j 1 1

i I I i ~ ~ 1 i

i i i i j

I I I I I I 1 I

16000 17000

0 0-300 mm depth

18000 19000 . STAT I 0 N

20000 21 000

300-600 mm depth A 600-900 mm depth Figure D-4

7n f V

60

50

40

30

20

10

0

i I

I I i I I I I ~ I I

1 I I I I I

!

6000 7000 8000 9000 10000 1 IQQO . STATION

I

0 0-300 mm depth

I "" I g I I - 1 I - j 1 I

rn 300-600 mm depth A 600-900 mm depth Figure D-5

. . . .

' \ , ' 1 :