Soil Stabilization for Pavements

Transcription

1 PDH-Pro.com Sol Stablzaton for Pavements Course Number: GE PDH: 2 Approved for: AK, AL, AR, GA, IA, IL, IN, KS, KY, MD, ME, MI, MN, MO, MS, MT, NC, ND, NE, NH, NJ, NM, NV, OH, OK, OR, PA, SC, SD, TN, TX, UT, VA, WI, WV, and WY New Jersey Professonal Competency Approval #24GP North Carolna Approved Sponsor #S-065 Ths document s the course text. You may revew ths materal at your lesure before or after you purchase the course. In order to obtan credt for ths course, complete the followng steps: 1) Log n to My Account and purchase the course. If you don t have an account, go to New User to create an account. 2) After the course has been purchased, complete the quz at your convenence. 3) A Certfcate of Completon s avalable once you pass the exam (70% or greater). If a passng grade s not obtaned, you may take the quz as many tmes as necessary untl a passng grade s obtaned (up to one year from the purchase date). If you have any questons or techncal dffcultes, please call (50) or emal us at admn@pdh-pro.com. Telephone (50) Washngton Street, Sute 15, Wellesley, MA

2 ENGINEER MANUAL EM A prl 14 ENGINEERING AND DESIGN Sol Stablzaton for Pavements Moblzaton Constructon DEPARTMENT OF THE ARMY CORPS OF ENGINEERS OFFICE OF THE CHIEF OF ENGINEERS

3 DEPARTMENT OF U. S. DAEN- ECE- G Eng neer No. Ar my THE ARMY Cor ps of Was h ngt on, EM Eng neer s D. C Manual Apr l 14 Eng neer ng and Des gn SOI L STABI LI ZATI ON FOR PAVEMENTS Mob l z at on Cons t r uc t on Th s manual pr ov des gu danc e f or t he des gn and mpr ov ement of 1. Pur pos e. t he s t r uc t ur al qual t y and wor k ab l t y of s o l s us ed f or bas e c our s es, s ubbas e c our s es, s el ec t mat er al s, Ar my mob l z at on and s ubgr ades f or pav ement s c ons t r uc t on f or U. S. f ac l t es. s appl c abl e t o al l f el d oper at ng Appl c ab l t y. Th s manual 2. ac t v t es hav ng mob l z at on c ons t r uc t on r es pons b l t es. 3. D s c us s on. Cr t er a and s t andar ds pr es ent ed her e n appl y t o pav ement t o a mob l z at on ef f or t. c ons t r uc t on c ons der ed c r uc al Thes e r equ r ement s may be al t er ed when nec es s ar y t o s at s f y s pec al c ond t ons on t he bas s of good eng neer ng pr ac t c e c ons s t ent w t h t he nat ur e of t he c ons t r uc t on. and c ons t r uc t on of mob l z at on f ac l t es mus t be c ompl et ed w t h n 10 day s f r om t he dat e not c e t o pr oc eed s g v en w t h t he pr oj ec t ed l f e ex pec t anc y of f v e y ear s. Henc e, r ap d c ons t r uc t on of a f ac l t y s houl d be Des gn r ef l ec t ed n ts des gn. pr ef er r ed ov er qu c k er Les s er gr ade mat er al s t he l es s er h gher T me- c ons um ng met hods met hods s houl d gr ade mat er al s def er r ed unt l such t me be bet t er and pr oc edur es, qual t y, s ubs t t ut ed f or ex t end c ons t r uc t on t he adequat e as t hey nor mal l y s houl d be de- emphas z ed. h gher woul d pr ov de s at s f ac t or y gr ade mat er al s woul d mmed at el y nec es s ar y f or f or t me. f unc t on ng of gr ade mat er al s s er v c e and when Wor k t ems t he f ac l t y c an be c ompl et ed w t hout FOR THE COMMANDER : PAUL F. Col on AVANAUGH Cor ps of Eng neer s Ch ef St af f of not s houl d be del ay ng t he mob l z at on ef f or t. when us e of

4 U. DEPARTMENT OF THE ARMY S. Ar my Cor ps of Eng neer s Wash ngt on, DC EM Eng neer Manual No Apr l Eng neer ng and Des gn SOI L STABI LI ZATI ON FOR PAVEMENTS Mob l z at on Const r uct on Par agr aph CHAPTER 1. GENERAL Pur pose and scope Def n t ons Met hods of st ab l zat on CHAPTER St ab l zat on appr oaches Cement cont ent f or mod f cat on of so l s Cement cont ent f or cement st ab l zed so l PURPOSE OF STABI LI ZATI ON Uses of st ab Sel ect on of Use of st ab l ar eas CHAPTER 3. CHAPTER 4. l zat on st ab l zer add t ve.. zed so l s n f r ost STABI LI ZATI ON WI TH PORTLAND CEMENT STABI LI ZATI ON WI TH LI ME St ab L me so L me so L me CHAPTER 5. l zat on cont ent f l s cont ent f l s and ot her appr oaches or l me- mod f ed or l me- st ab l zed add t ves STABI LI ZATI ON WI TH LI ME- CEMENT- FLY ASH ( LCF) React on w t h so l s Su t abl e mat er al s LCF cont ent CHAPTER 6. Pal e , STABI LI ZATI ON WI TH BI TUMEN Types of b t um nous- st ab l zed so l s

5 EM Apr 4 Par agr a, ~h So l gr adat on Types of b t umen M x des gn APPENDI X A. APPENDI X B PA TEST TO DETERMI NE LI ME REQUI REMENTS FOR LI ME STABI LI ZATI ON A- 1 REFERENCES B- 1 LI ST OF TABLES Tabl e 2-1. Page M n mum unconf ned compr ess ve st r engt hs f or cement, l me, and comb ned l me- cement - f l y ash st ab l zed so l s. Gu de f or sel ect ng a st ab l z ng add t ve. Gr adat on r equ r ement s. Est mat ed cement r equ r ement s f or var ous so l t ypes. Aver age cement r equ r ement s f or gr anul ar and sandy so l s. Aver age cement r equ r ement s f or s l t y and cl ayey so l s. Dur ab l t y r equ r ement s. Recommended gr adat ons f or b t um nousst ab l zed subgr ade mat er al s. Recommended gr adat ons f or b t um nousst ab l zed base and subbase mat er al s. Emul s f ed asphal t r equ r ement s.

6 EM Apr 4 CHAPTER 1 GENERAL 1-1. Pur pose and scope. Th s manual pr esent s cr t er a f or mpr ov ng t he st r uct ur al qual t y and wor kab l t y of so l s used f or base cour ses, subbase cour ses, sel ect mat er al s, and subgr ades f or pavement s. It s appl c abl e t o al l el ement s r espons bl e f or at mob l z at on f ac l t es Def n t ons. manual. Ar my The f ol l ow ng def n t ons pavement const r uct on ar e appl cabl e t o t h s a. So l s. The t er m " so l s" r ef er s t o nat ur al l y occur r ng mat er al s t hat ar e used f or t he const r uct on of al l except t he sur f ace l ayer s of pavement s and t hat ar e subj ect t o cl ass f cat on t est s t o pr ov de a gener al concept of t he r eng neer ng char act er st cs. Al so ncl uded ar e t he mat er al s nor mal l y used f or base cour ses, subbase cour ses, sel ect mat er al l ayer s, and subgr ades. The so l cl ass f cat on syst em t o be used n eval uat ng t hese char act er st cs s descr bed n MI L- STD- 61. St ab l zat on s t he pr ocess of bl end ng and b. St ab l zat on. m x ng mat er al s w t h a so l t o mpr ove t he per t nent pr oper t es of t he so l. The pr ocess may ncl ude t he bl end ng of so l s t o ac h ev e a des r ed gr adat on or t he m x ng of commer c al l y ava l abl e add t ves t hat may al t er t he gr adat on, change cer t a n pr oper t es, or act as a b nder f or cement at on of t he so l. c. Mod f cat on. Mod f cat on r ef er s t o t he st ab l zat on pr ocess t hat r esul t s n mpr ovement n some pr oper t y of t he so l but does not by des gn r esul t n a s gn f cant ncr ease n so l st r engt h and dur ab l t y. d. Add t ve. Add t ve r ef er s t o a manuf ac t ur ed commer c al pr oduct t hat, when added t o t he so l n t he pr oper quant t es, w l l mpr ove t he qual t y of t he so l l ayer. Th s manual s r est r ct ed t o t he use of por t l and cement, l me, l me- cement - f l y ash, and b t umen, al one or n comb nat on, as add t ves t o st ab l ze so l s. The t wo gener al met hods of 1-3. Met hods of st ab l zat on. The ef f ect veness st ab l zat on pr esent ed ar e mechan cal and add t ve. of st ab l zat on s dependent upon t he ab l t y t o obt a n un f or m t y n M x ng n a st at onar y or t r avel ng bl end ng t he var ous mat er al s. pl ant s pr ef er r ed ; however, ot her means of m x ng, such as scar f e, r s, pl ows, d sks, gr ader s, and r ot ar y m xer s, hav e been sat sf act or y. Mechan cal st ab l zat on s a. Mechan cal st ab l zat on. accompl shed by m x ng or bl end ng so l s of t wo or mor e gr adat ons The so l obt a n a mat er al meet ng t he r equ r ed spec f cat on. to

7 EM Apr 4 bl end ng may t ake pl ace at t he const r uct on s t e, at a cent r al pl ant, or at a bor r ow ar ea. The bl ended mat er al s t hen spr ead and compact ed t o r equ r ed dens t es by convent onal means. b. Add t ve st ab l zat on. Two t ypes of add t ve st ab l zat on ar e chem cal and b t um nous. Chem cal st ab l zat on s ach eved by t he add t on of pr oper per cent ages of cement, l me, f l y ash, or B t um nous st ab l zat on comb nat ons of t hese mat er al s t o t he so l. s ach eved by t he add t on of pr oper per cent ages of b t um nous mat er al t o t he so l. The sel ect on and det er m nat on of t he per c ent age of add t ve t o be added s dependent upon t he so l cl ass f cat on and t he degr ee of mpr ovement n so l qual t y des r ed. Gener al l y, smal l er amount s of add t ves ar e r equ r ed when t s s mpl y des r ed t o al t er so l pr oper t es, such as gr adat on, wor kab l t y, and pl ast c t y, t han when t s des r ed t o mpr ove t he st r engt h and Af t er dur ab l t y suf f c ent l y t o per m t a t h ckness r educt on des gn. ar e so l, spr ead ng and com paat on has been m xed w t h t he t he add t ve convent onal m eans. ach eved by

8 EM Apr 4 CHAPTER 2 PURPOSE OF STABI LI ZATI ON 2-1. t hat Uses of st ab l zat on. Pavement des gn s based on t he pr em se spec f ed l evel s of qual t y w l l be ach eved f or each so l l ayer n t he pavement syst em. Each l ayer must r es st shear ng w t h n t he l ayer, avo d excess ve el ast c def l ect ons t hat woul d r esul t n f at gue cr ack ng w t h n t he l ayer or n over l y ng l ayer s, and pr event excess ve per manent def or mat on t hr ough dens f cat on. As t he qual t y of a so l l ayer s ncr eased, t he ab l t y of t hat l ayer t o d st r but e t he l oad ov er a gr eat er ar ea s gener al l y ncr eased enough t o per m t a r educt on n t he r equ r ed t h ckness of t he so l and sur f ace l ayer s. a. I mpr ov e qual t y. The most common so l qual t y mpr ovement s t hr ough st ab l zat on ncl ude bet t er so l gr adat on, r educt on of pl ast c t y ndex or swel l ng pot ent al, and ncr eases n dur ab l t y and n st r engt h. I t s al so common t o st ab l ze a so l by an add t ve n or der t o pr ov de an al l - weat her wor k ng pl at f or m f or const r uct on oper at ons. These t ypes of so l qual t y mpr ovement ar e r ef er r ed t o as m od f cat ons. so l The t ens l e st r engt h and st f f ness of a so l b. Reduce t h ckness. can be m pr oved t hr ough t he use of add t ves and t her eby per m t a l ayer r educt on n t he t h ckness of t he st ab l zed l ayer and over l y ng l ayer s Bef or e a st ab l zed l ayer can be used t o w t h n t he pavement syst em. r educe t he r equ r ed t h ckness n t he des gn of a pavement syst em, t he st ab l zed mat er al must meet t he dur ab l t y r equ r ement s g ven n par agr aph 2-2 on var ous t ypes of add t ve st ab l zat on and t he m n mum st r engt h r equ r ement s shown n t abl e 2-1. Tabl e 2-1. M n mum Unconf ned Compr ess ve St r engt hs f or Cement, L me, and Comb ned L me- Cement - Fl y As h St ab l zed So l s M n mum Unconf ned Co mpr ess ve St r engt h, ps a St ab l zed So l Layer Fl ex bl e Pavement R g d Pavement Base cour se Subbase cour se, sel ect mat er al or subgr ade aunc onf ned compr ess ve st r engt h det er m ned at 7 days f or cement st ab l zat on and 7 or 2 days f or l me or l me- cement - f l y ash st ab l zat on ( See chapt er 4)

9 EM Apr Sel ect on of st ab l zer add t ve. I n t he sel ect on of a st ab l zer add t ve, t he f act or s t hat must be cons der ed ar e t he t ype of so l t o be st ab l zed, t he pur pose f or wh ch t he st ab l zed l ayer w l l be used, t he t ype of so l qual t y mpr ovement des r ed, t he r equ r ed st r engt h and dur ab l t y of t he st ab l zed l ayer, and cost and env r onment al cond t ons. a. The so l gr adat on t r angl e n f gur e 2-1 s based upon t he pul v er z at on char act er st cs of t he so l t hat, when comb ned w t h c er t a n r est r ct ons r el at ve t o l qu d l m t ( LL) pl ast c t y ndex ( ), and so l gr adat on cont a ned n t abl e 2-2, pr ov de gu dance f or t he sel ect on of t he add t ve best su t ed f or st ab l zat on. F gur e 2-1 s ent er ed w t h t he per cent age of gr avel ( per cent mat er al r et a ned on No. 4 s eve), sand ( per cent mat er al pass ng No. 4 s eve and r et a ned on t he No. 200 s eve), and f nes ( per cent mat er al pass ng t he No. 200 s eve) t o det er m ne t he ar ea n wh ch t he so l gr adat on f al l s. The ar ea OA, 2C, 3, et c. ) nd cat ed at t he nt er sect on of t he t hr ee mat er al per cent ages s used t o ent er t abl e 2-2 t o sel ect t he t ype of s t ab l z ng add t ve cons der ng t he var ous r est r ct ons and r emar ks. For exampl e, a so l hav ng a of 15 and cont a n ng 67 per cent gr avel, 26 per cent sand, and 7 per cent f nes f al l s n Ar ea 2B of f gur e 2-1. Tabl e 2-2 nd cat es t hat cement, l me, l me- cement - f l y ash, or b t umen coul d be cons der ed. However, t he of 15 el m nat es b t umen, and t he f act t hat onl y 33 per cent of t he mat er al passes t he No. 4 s eve nd cat es t hat l me. or a comb nat on of l me- cement - f l y ash w l l be t he bet t er add t ve f or st ab l zat on. b. The next cons der at on n t he sel ect on of an add t ve w l l be t he use of t he st ab l zed l ayer. I f t s onl y des r ed t o mod f y t he pr oper t es of t he so l (. e., l ower t he and ncr ease per cent f nes) so t hat t woul d qual f y as a subbase or base cour se mat er al, l me may wel l be t he best add t ve. I f, however, h gh st r engt hs and good dur ab l t y ar e r equ r ed t o ef f ect a r educt on n pavement t h ckness, t he use of a l me- cement or l me- cement - f l y ash comb nat on may be t he best add t ve. Act ual l y, t he best add t ve can onl y be det er m ned by st ud es as out l ned l at er n t t s manual. The success of add t ve s t ab l z at on depends, t o a l ar ge ext ent, upon at t a n ng compl et e and un f or m d st r but on of t he add t ve n t he so l. Th s st ep s most cr t cal when us ng b t umens or por t l and cement as add t ves. These mat er al s wor k wel l n coar se- gr a ned so l s t hat pul ver ze mor e eas l y. Gener al l y, as t he per cent f nes and t he ncr ease, pul ver zat on becomes mor e d f f cul t, and t s har der t o obt a n un f or m d s t r but on For t hese t ypes of so l s, pr epr ocess ng of t he st ab l z ng add t ve. For exampl e, or pr et r eat ment w t h ot her add t ves may be necessar y. f ne- gr a ned so l s may be pr et r eat ed w t h l me t o a d n t he r pul ver zat on, mak ng m x ng of a b t umen or cement add t ve mor e successf ul.

10 EM Apr 4 LEGEND - ' zyxwvutsrqponmlkjhgfedcbazyxwvutsrqponmlkjihgfedcba " - - " - Boundar es bet ween maj or so l -- " " Boundar es w t h n a maj or so l gr oups. gr oup. 0 PERCENT BY WEI GHT, FI NES ( MATERI AL PASSI NG N SI EVE) U. S. Ar my Cor ps of Eng neer s FI GURE 2- l. GRADATI ON TRI ANGLE FOR AI D I N SELECTI NG A CONLMERCI AL STABI LI ZI NG AGENT

11 EM Apr 4 Tabl e 1-2. Ar ea IA 1B 1C 2A 2B 2C 3 a ' So l s Cl ass. a SW or SP SW- SM or SP- SM or SW- SC or SP- SC SM or SC or SM- SC GW or GP GW- GM or GP- GM or GW- GC or GP- GC GM or GC or GM- GC CH or or MH ML or or OL ML- CL CL or OH or Gu de f or 20 + Rest r ct on on Per cent Pass ng No. 200 S eve a Type of St ab l z ng Add t ve Recommended Rest r ct on on LL and of So l ( 1) ( 2) ( 3) B t um nous Por t l and Cement L me- Cement - Fl y Ash not t o exceed 25 ( 1) ( 2) ( 3) ( 4) B t um nous Por t l and Cement L me L me- Cement - Fl y As h not not not not t t l t ( 1) B t um nous - not ( 2) ( 3) ( 4) Por t l and Cement L me L me- Cement - Fl y As h ( 1) ( 2) B t um nous Por t l and Cement ( 3) L me- Cement - Fl y As h not ( 1) ( 2) B t um nous Por t l and Cement not t o exceed not t o exceed 30 ( 3) ( 4) L me L me- Cement - Fl y As h not l ess t han not t o exceed 25 ( 1) B t um nous not t o exceed ( 2) Por t l and Cement ( 3) ( 4) L me L me- Cement - Fl y As h ( 1) Por t l and LL l ess Cement L me 50 - per cent pass ng No. 200 s eve 4 U. S. Ar my Cor ps of Eng neer s t o exceed Not t o exceed 30 per cent by we ght ----b not l ess t han not t o exceed 25 t o exceed 25 Wel l - gr aded mat er al onl y Mat er al shoul d cont a n at l east 45 per cent by we ght of mat er al pass ng No. 4 s eve Not t o exceed 30 per cent by we ght ---b ( 2) o exceed o exceed ess t han o exceed Remar ks Wel l - gr aded mat er al onl y Mat er al shoul d cont a n at l east 45 per cent by we ght of mat er al pass ng No. 4 s eve So l cl ass f cat on cor r esponds t o MI L- STD- 61. n accor dance w t h Met hod 3 n MI L- STD b Sel ect ng a St ab l z ng Add t ve not not onl y Mat er al shoul d cont a n at l east 45 per cent by we ght of mat er al pass ng No. 4 s eve l ess t han t o exceed 25 t han 40 and l ess t han 20 not Wel l - gr aded mat er al Or gan c and st r ongl y ac d so l s f al l ng w t h n t h s ar ea ar e not suscept bl e t o st ab l zat on by or d nar y means l ess t han Rest r ct on on l qu d l m t ( LL) and pl ast c t y ndex ( )

12 EM g Apr Use of st ab l zed so l s n f r ost ar eas. a. Add t ves. B t umens, por t l and cement, l me, and comb nat ons of l me, por t l and cement, and f l y ash ( LCF) ar e t he most common add t ves f or use n st ab l zed so l s. b. L m t at ons of use. I n f r ost ar eas, st ab l zed so l usual l y w l l be used onl y n. a l ayer or l ayer s compr s ng one of t he upper el ement s of a pavement syst em and d r ect l y beneat h t he pavement s ur f ac ng l ayer, wher e t he added cost of st ab l zat on s compensat ed f or by t s st r uct ur al advant age n ef f ect ng a r educt on n t he r equ r ed t h ckness of t he pavement syst em. Tr eat ment w t h a l ower degr ee of chem cal st ab l zat on shoul d be used n f r ost ar eas onl y w t h caut on and af t er nt ens ve t est s, because weakl y cement ed mat er al usual l y has l ess capac t y t o endur e r epeat ed f r eez ng and t haw ng t han f r ml y cement ed mat er al. A poss bl e except on s t he use of a l ow l evel of st ab l zat on t o mpr ove a so l t hat w l l be encapsul at ed w t h n an mper v ous envel ope as par t of a membr ane- enc aps ul at ed- s o l - l ay er pavement syst em. A so l t hat s unsu t abl e f or encapsul at on due t o excess ve mo st ur e m gr at on and t haw weak en ng may be made su t abl e f or such use by moder at e amount s of Mat er al s t hat ar e mod f ed by smal l amount s a st ab l z ng add t ve. of a chem cal add t ve t o mpr ove cer t a n pr oper t es of t he so l w t hout s gn f cant cement at on al so shoul d be t est ed t o ascer t a n t hat t he des r ed mpr ovement s dur abl e t hr ough r epeat ed f r eeze- t haw cycl es. The mpr ovement shoul d not be ach eved at t he expense of mak ng t he so l mor e suscept bl e t o ce segr egat on. Add t onal d scuss ons on so l n seasonal f r ost ar eas ar e pr esent ed n EM t he use of st ab l zed Const r uct on cut of f dat es. For mat er al s st ab l zed w t h c. cement, l me, or LCF whose st r engt h ncr eases w t h t me of cur ng, t s essent al t hat t he st ab l zed l ayer be const r uct ed suf f c ent l y ear l y n t he season t o al l ow t he devel opment of adequat e st r engt h The r at e of st r engt h ga n s bef or e t he f r st f r eez ng cycl e beg ns. subst ant al l y l ower at 50 degr ees F. t han at 70 or 0 degr ees F. Chem cal r eact ons w l l not occur r ap dl y f or ( 1) l me- st ab l zed so l s when t he so l t emper at ur e s l ess t han 60 degr ees F. and s not expect ed t o ncr ease f or 1 mont h, or ( 2) cement - st ab l zed so l s when t he so l t emper at ur e s l ess t han 40 degr ees F. and s not expect ed t o I n f r ost ar eas, t s not al ways suf f c ent t o ncr ease f or 1 mont h. pr ot ect t he m xt ur e f r om f r eez ng dur ng a 7- day cur ng per od as r equ r ed by t he appl cabl e gu de spec f cat ons, and a const r uct on cut of f dat e wel l n advance of t he onset of f r eez ng cond t ons may be essent al.

13 EM Apr 4 CHAPTER 3 STABI LI ZATI ON WI TH PORTLAND CEMENT 3-1. St ab l zat on appr oaches. Por t l and cement can be used e t her t o mod f y and mpr ove t he qual t y of t he so l or t o t r ansf or m t he so l nt o a cement ed mass, wh ch s gn f cant l y ncr eases t s st r engt h and dur ab l t y. The amount of cement add t ve w l l depend upon whet her t he so l s t o be mod f ed or st ab l zed Cement cont ent f or mod f c at on of so l s. a. Mod f c at on of qual t y. The amount of cement r equ r ed t o mpr ove t he qual t y of t he so l t hr ough mod f cat on s det er m ned by t he t r al - and- er r or appr oach. I f t s des r ed t o r educe t he of t he so l, success ve sampl es of so l - cement m xt ur es must be pr epar ed at d f f er ent t r eat ment l evel s and t he of each m xt ur e det er m ned. The Ref er ee Test of ASTM D 423 and ASTM D 424 pr ocedur es w l l be used t o det er m ne t he of t he so l - cement m xt ur e. The m n mum cement cont ent t hat y el ds t he des r ed s sel ect ed, but s nce t was det er m ned based upon t he m nus 40 f r act on of t he mat er al, t h s val ue must be adj ust ed t o f nd t he des gn cement cont ent based upon t ot al sampl e we ght expr essed as t he f ol l ow ng equat on : A = 0Bc wher e : A = des gn cement cont ent, per cent t ot al we ght of so l B = per cent pass ng No. 40 s eve s ze, expr essed as a dec mal c = per cent cement r equ r ed t o obt a n t he des r ed of m nus 40 mat er al, expr essed as a dec mal. b. Mod f cat on of gr adat on. I f t he obj ect ve of mod f c at on s t o mpr ove t he gr adat on of gr anul ar so l t hr ough t he add t on of f nes, t he par t cl e- s ze anal ys s, us ng t he ASTM D 422 pr ocedur e, shoul d be conduct ed on sampl es at var ous t r eat ment l evel s t o det er m ne The det er m nat on of cement t he m n mum accept abl e cement cont ent. cont ent t o r educe t he swel l pot ent al of f ne- gr a ned pl ast c so l s can be accompl shed by mol d ng sever al sampl es at var ous cement cont ent s and soak ng t he spec mens al ong w t h unt r eat ed spec mens f or 4 days. The l owest cement cont ent t hat el m nat es t he swel l pot ent al or r educes t he swel l char act er st cs t o t he m n mum becomes t he des gn cement cont ent. Pr ocedur es f or meas ur ng swel l char act er st cs of The cement cont ent so l s ar e f ound n MI L- STD- 621, Met hod 1. m od f cat on shoul d be checked t o see det er m ned t o accompl sh so l com pr ess ve st r engt h gr eat enough t o whet her t pr ov des an unconf ned n accor dance w t h cr t er a qual f y f or a r educed t h ckness des gn. est abl shed f or so l st ab l zat on

14 EM Apr 4 C. Mod f cat on f or f r ost ar eas. Cement - mod f ed so l al so may be used n f r ost ar eas, but n add t on t o t he pr ocedur es f or m xt ur e des gn descr bed n 3-2. a. and 3-2. b. above, cur ed spec mens shoul d be subj ect ed t o t he f r eeze- t haw cycl es pr escr bed by ASTM D 560 ( but om t t ng w r e- br ush ng) or ot her appl cabl e f r eeze- t haw pr ocedur es, f ol l owed by f r ost - suscept b l t y det er m nat ons n st andar d l abor at or y f r eez ng t est s. For cement - mod f ed so l used n t he base c our s e, t he f r ost suscept b l t y, det er m ned af t er f r eeze- t haw cycl ng, shoul d meet I f cement - mod f ed t he r equ r ement s set f or t h f or t he base cour se. so l s used as t he subgr ade, t s f r ost suscept b l t y, det er m ned af t er f r eeze- t haw cycl ng, shoul d be used as t he bas s of t he pavement t h ckness des gn f t he r educed subgr ade st r engt h des gn met hod s appl ed ( EM ). For mob l zat on, t he use of ASTM D 560 may be al t er ed t o 6 cycl es of 6 hour s of f r eeze/ wet - 6 hour t haw/ dr y. Per cent ages of st ab l zer sel ect ed f or use may be based on l ocal per f or mance h st or y n l eu of t hese t est s. The f ol l ow ng 3-3. Cement cont ent f or cement - st ab l zed so l. pr ocedur e s r ecommended f or det er m n ng t he des gn cement cont ent cement - st ab l zed so l s. f or a. Det er m ne t he cl ass f cat on and gr adat on of t he St ep 1. unt r eat ed so l f ol l ow ng pr ocedur es n MI L- STD- 61 and ASTM D 422, The so l must meet t he gr adat on r equ r ement s shown n r espect vel y. t abl e 3-1 bef or e t can be used n a r educed t h ckness des gn. Tabl e 3-1. Gr adat on Requ r ement s Type Cour se S eve S ze Per cent Pass ng Base 2- nch 1-1/ 2- = nch 1- nch 3/ 4- nch 1/ 2- nch No. 4 No. No. 30 No. 40 No nch No. 4 No. No. 0 No Subbase

15 EM Apr 4 b. St ep 2. Sel ect an est mat ed cement t he so l cl ass f cat on. " Tabl e 3-2. Est mat ed Cement cont ent Requ r ement s I n t al So l Cl ass f cate on a P r f or Var ous So l 5 GP, SW- SM, SW- SC, SW- GM, SW- GC 6 GM, SM, SP- SM, GC, SC, SP- SC, GP- GM SM- SC, GM- GC 7 ML, SP, CL, a So l ML- CL cl ass f cat on cor r esponds Types Est mat ed Cement Requ r ement cent Dr y We ght GW- SW GP- GC, f r om t abl e 3-2 us ng t o MI L- STD- 61. c. St ep 3. Us ng t he est mat ed cement cont ent, det er m ne t he mo s t ur e- dens t y r el at ons of t he so l - cement m xt ur e. The pr ocedur e cont a ned n ASTM D 55 w l l be used t o pr epar e t he so l - cement m x t ur e and t o make t he necessar y cal cul at ons ; however, t he appar at us and pr ocedur es out l ned n MI L- STD- 621, Met hod 0, Compact on Ef f or t Des gnat on CE- 55 w l l be used t o compact t he so l - cement m xt ur e. d. St ep 4. cont ent, Us ng t he unt r eat ed so l gr adat on char act er st cs, and max mum dr y dens t y det er m ned n St eps 1, 2, and cement 3, r espect vel y, ver f y t he est mat ed cement cont ent us ng t abl e 3-3 or I f t he t abl e 3-4 and f gur e 3-1 depend ng upon so l cl ass f cat on. cont ent f r om St ep 2 var es by m or e t han pl us or m nus est mat ed cement t he val ue n t abl e 33 or t abl e 34, conduct add t onal 2 per cent f r om t est s, var y ng t he cem ent cont ent, unt l t he val ue mo s t ur e- dens t y f r om t abl e 3-3 or t abl e 3-4 s w t h n pl us or m nus 2 per cent of t hat The mo st ur e- dens t y t est w l l be used f or t he mo st ur e- dens t y t est. out l ned n St ep 3. per f or med as Pr epar e sampl es of t he so l - cement m xt ur e f or e. St ep 5. unconf ned compr ess on and dur ab l t y t est s at t he dr y dens t y and at t he cement cont ent det er m ned n St ep 4 and at cement cont ent s 2

16 Tabl e 3-3. Mat er al Smal l er Than mm per cent Mat er al Ret a ned on No. 4 S eve per cent Not e ; U. S. Aver age Cement Requ r ement s f or Gr anul ar and Sandy So l s Y 6-0 Cement Cont ent, Max mum Dr y Dens t y, Per cent by We ght pcf ( Tr eat ed Mat er al ) {' w 143 or Base cour se goes Ar my Cor ps of t o 70 per cent Eng neer s r et a ned on t he No. 4 s eve. mor e

17 Tabl e 3-4. Av er age Cement Requ r ement s f or S l t y and Cl ay ey So l s Mat er al Bet ween and Cement Gr oup mm I ndex per c ent or or or mor e mor e I or mor e 60 o r mor e atak en by We ght ( Tr eat ed Mat er al ) pc f Per c ent or mor e 3-7 Cont ent, Max mum Dr y Dens t y, f r om f gur e t I mor e

18 EM Apr 4 OR LESS PERCENT PASSI NG NO OR MORE 50 l l ~MQ " ~- I O 'OR LESS' 55 0 y 4 \v v 6 W 0 z kl e M E 75 OR MORE NOTE : PERCENT PASSI NG NO OR LESS Gr oup I ndex = I ndex a + I ndex b. REPRI NTED FROM SOI L- CEMENT LABORATORY HANDBOOK ( EB S) WI TH PERMI SSI ON OF THE PORTLAND CEMENT ASSOCI ATI ON, SKOKI E, I LLI NOI S. FI GURE 3-1. CHARTS FOR CALCULATI NG GROUP I NDEX VALUES 3-6

19 EM Apr 4 per cent above and 2 per cent bel ow t hat det er m ned n St ep 4. The sampl es shoul d be pr epar ed n accor dance w t h ASTM D 1632 except t hat when mor e t han 35 per cent of t he mat er al s r et a ned on t he No. 4 s eve, a 4- nch- d amet er by - nch- h gh mol d shoul d be used t o pr epar e t he spec mens. Cur e t he spec mens f or 7 days n a hum d r oom bef or e t est ng. Test t hr ee spec mens us ng t he unconf ned compr ess on t est n ac c or danc e w t h ASTM D 1633, and subj ect t hr ee spec mens t o dur ab l t y t est s, e t her wet - dr y ( ASTM D 55) t est s f or pavement s l ocat ed n nonf r ost ar eas or f r eeze- t haw ( ASTM D 560) t est s f or pavement s l ocat ed n f r ost ar eas ( EM ). For mob l zat on, t he use of ASTM D 560 may be al t er ed t o 6 cycl es of 6 hour s of f r eeze/ wet - 6 hour t haw/ dr y. Per cent ages of st ab l zer sel ect ed f or use may be based on l ocal per f or mance h st or y n l eu of t hese t est s. f. St ep 6. Compar e t he r esul t s of t he unconf ned compr ess ve st r engt h and dur ab l t y t est s w t h t he r equ r ement s shown n t abl es 2-1 and 3-5. The l owest cement cont ent, wh ch meet s t he r equ r ed unconf ned compr ess ve st r engt h r equ r ement and demonst r at es t he I f t he m xt ur e r equ r ed dur ab l t y, s t he des gn cement cont ent. shoul d meet t he dur ab l t y r equ r ement s but not t he st r engt h r equ r ement s, t he m x t ur e s cons der ed t o be a mod f ed so l. Tabl e 3-5. Dur ab l t y Requ r ement s Max mum Al l owabl e We ght Loss Af t er Wet - Dr y or 6 Fr eeze- Thaw Cycl es Per cent of I n t al Spec men We ght Type of So l St ab l zeda Gr anul ar, l ess t han Gr anul ar, gr eat er t han S l t Cl ays 6 aref er t o MI L- STD- 61 and MI L- STD- 621.

20 EM Apr 4 CHAPTER 4 STABI LI ZATI ON WI TH LI ME 4-1. St ab l zat on appr oaches. L me can be used e t her t o mod f y some of t he phys cal pr oper t es and t her eby mpr ove t he qual t y of a so l or t o t r ans f or m t he so l nt o a st ab l zed mass, wh c h ncr eases t s st r engt h and dur ab l t y. The amount of l me add t ve w l l depend upon whet her t he so l s t o be mod f ed or st ab l zed. The l me t o be used may be e t her hydr at ed or qu ckl me, al t hough t he pr eponder ance of s t ab l z at on s accompl shed us ng hydr at ed l me, s nce qu ckl me s h ghl y caust c and danger ous t o use. The des gn l me cont ent s det er m ned f r om t he cr t er a pr esent ed her e n ar e f or hydr at ed l me. As a gu de, t he l me cont ent s det er m ned her e n f or hydr at ed l me shoul d be r educed by 25 per cent t o det er m ne a des gn cont ent f or qu c k l me L me cont ent f or l me- mod f ed so l s. The amount of l me r equ r ed t o mpr ove t he qual t y of a so l s det er m ned t hr ough t he same t r al - and- er r or pr ocess used f or cement - mod f ed so l s L me cont ent f or l me- st ab l zed so l s. a. St r engt h r equ r ement s. To t ake advant age of t he t h ckness r educt on cr t er a, t he l me- st ab l zed so l must meet t he unconf ned compr ess ve st r engt hs shown n t abl e 2-1 as wel l as t he dur ab l t y r equ r ement s n t abl e 3-5. b. Pr ocedur es. When l me s added t o a so l, a comb nat on of r eact ons beg ns t o t ake pl ace mmed at el y and s near l y compl et e w t h n an hour, al t hough subst ant al st r engt h ga n s not r ef l ect ed f or some t me. These r eact ons r esul t n a change n bot h t he chem cal compos t on and phys cal pr oper t es. Most l me, when pl aced n a wat er sol ut on, has a ph of about. 4. Ther ef or e, t he ph s a good nd cat or of t he des r abl e l me cont ent of a so l - l me m xt ur e. The r eact on t hat t akes pl ace when l me s nt r oduced t o a so l gener al l y causes a s gn f cant change n t he pl ast c t y of t he so l ; t her ef or e, t he changes n t he pl ast c and l qu d l m t s al so. become an nd cat or of t he des r ed l me cont ent. Two met hods ar e pr esent ed f or t he det er m nat on of t he n t al des gn l me cont ent. ( 1) St ep 1. The pr ef er r ed met hod s t o pr epar e sever al m xt ur es at d f f er ent l me t r eat ment l evel s and det er m ne t he ph of each m x t ur e af t er 1 hour. The l owest l me cont ent pr oduc ng t he h ghest ph of t he so l - l me m xt ur e s t he n t al des gn l me cont ent. Pr ocedur es f or conduct ng a ph t est on l me- so l m xt ur es ar e pr esent ed n append x A. I n f r ost ar eas, spec mens must be subj ect ed t o t he f r eeze- t haw t est as d scussed n St ep 2 bel ow. An al t er nat e met hod of det er m n ng an n t al des gn l me cont ent s by t he use of f gur e 4-1. Spec f c v al ues r equ r ed t o use f gur e 4-1 ar e t he and t he per cent of

21 EM - 3=137 Apr 4 P. I. - WET METHOD z 0 r U II c 0 x w 60 r FAN E- + G 50 I TO w E~ a 60 z E-F-+ z cr, z H 30 w z z w w w 20 a. I- - * EXCLUDED BI NDER AREA w w I 0 5 SEI LE SECTI ON, MATERI ALS a TEST DI VI SI ON, TEXAS HI GHWAY DEPT P. I. - W ET METHOD z EXAMPLE 1. Ent er 2. Fol l ow c ur v ed pl ot w t h Pl on t op s c al e. l ne down t o per c ent so l b ( o/ o pas s ng No. 40). At nt er s ec t on w t h per c ent so l b nder, v er t c al l y upwar d t o t he per c ent so l Read t he per c ent l me r epr es ent ed at t he mov e w t h t he 0 per c ent For so l hav ng a P1 t he l me r equ r ed s s o l so l Ex c l ude us e of f or c har t and c ohes onl es s ** b nder mat er al s (P.I. b nder l ne. nt er s ec t on l ne. of 31) and 55 per c ent 4-1/ 4 per c ent. mat er al s nder l es s l ess t han t han b nder, per c ent - No. 40 3). of r el at v el y pur e l me us ual l y 0 per c ent of mor e of CO and/ or MG hy dr ox des and 5 per c ent or mor e of wh c h pas s t he No. 200 s ev e. Per c ent ages s hown ar e f or s t ab l z ng s ubgr ades and base c our s es wher e l as t ng ef f ec t s ar e des r ed. Sat s f ac t or y t empor ar y r es ul t s ar e s omet mes obt a ned by t he us e of as l t t l e Per c ent Ref er enc e t o c ement ng s t r engt h as 1/ 2 of abov e per c ent ages. mpl ed when s uc h t er ms as " Las t ng Ef f ec t s " and " Tempor ar y Resul t s" s ar e us ed. f r om t he Nat onal L me As s oc at on CHART FOR THE I NI TI AL DETERMI NATI ON OF LI ME CONTENT 4-2 Repr nt ed w t h per m s s on FI GURE 4- l. 1

22 EM Apr 4 These pr oper t es ar e det er m ned mat er al pass ng t he No. 40 s eve. f r om pl ast c l m t and gr adat on t est s on t he unt r eat ed so l f ol l ow ng pr ocedur es est abl shed n MI L- STD St ep 2. Af t er t he n t al l me cont ent has been est mat ed, ( 2) conduct a mo st ur e- dens t y t est w t h t he l me- so l m xt ur e f ol l ow ng t he pr ocedur es f or so l - cement n ASTM D 55, except t hat t he m x t ur e s houl d be al l owed t o cur e no l ess t han 1 hour and no mor e t han 2 hour s n a seal ed cont a ner bef or e mol d ng. Compact on w l l be accompl shed n accor dance w t h MI L- STD- 621, Met hod 0, Compact on Ef f or t The mo st ur e- dens t y shoul d be det er m ned at l me Des gnat on CE- 55. cont ent s equal t o des gn pl us 2 and pl us 4 per cent f or t he pr ef er r ed met hod and at des gn pl us or m nus 2 per cent f or t he al t er nat e met hod. I n f r ost ar eas, cur ed spec mens shoul d be subj ect ed t o ASTM D 560 ( but om t t ng w r e- br ush ng) or ot her appl cabl e f r eeze- t haw pr ocedur es, f ol l owed by f r ost suscept b l t y det er m nat ons n st andar d l abor at or y f r eez ng t est s ( EM ). For mob l zat on, t he use of ASTM D 560 may be al t er ed t o 6 cycl es of 6 hour s of f r eeze/ wet - 6 hour t haw/ dr y. Per cent ages of st ab l zer sel ect ed f or use may be based on l ocal per f or mance h s t or y n l eu of t hese t est s. For l me- st ab l zed or l me- mod f ed so l used n l ower l ayer s of t he base cour se, t he f r ost suscept b l t y, det er m ned af t er f r eeze- t haw cycl ng, shoul d meet t he r equ r ement s set f or t h f or t he base cour se ( EM ). If l me- st ab l zed or l me- mod f ed so l s used as t he subgr ade, t s f r ost suscept b l t y, det er m ned af t er f r eeze- t haw cycl ng, shoul d be used as t he bas s of t he pavement t h ckness des gn f t he r educed subgr ade st r engt h des gn met hod s appl ed. St ep 3. Unconf ned compr ess on t est s shoul d be per f or med at ( 3) t he des gn per cent of max mum dens t y on t hr ee spec mens f or each l me cont ent t est ed. The des gn val ue woul d t hen be t he m n mum l me Pr ocedur es f or t he pr epar at on cont ent y el d ng t he r equ r ed st r engt h. of l me- so l spec mens ar e s m l ar t o t hose used f or cement - st ab l zed Af t er m x ng, t he l me- so l m xt ur e shoul d so l s w t h t wo except ons. be al l owed t o mel l ow f or not l ess t han 1 hour or mor e t han 2 hour s ; af t er compact on, each spec men shoul d be wr apped secur el y t o pr event mo s t ur e l oss and cur ed n a const ant t emper at ur e chamber at 73 degr ees For mob l zat on, t he r equ r ed pl us or m nus 2 degr ees F f or 2 days. cur ng of t he sampl e may be r educed t o 7 days at 140 F. as an Caut on mus t be t aken, appr ox mat on of t he 2 day so l st r engt h. however, s nce cer t a n pozzol an c r eact ons may occur at h gher t est t emper at ur es wh ch woul d not be dupl cat ed at const r uct on t emper at ur es. I n add t on, t he r el at onsh p bet ween age, t emper at ur e, Pr ocedur es and st r engt h s not t he same f or al l l me- so l m xt ur es. f or conduct ng unconf ned compr ess on t est s ar e s m l ar t o t hose used f or so l - cement spec mens except t hat n l eu of mo st cur ng, t he l me- so l spec mens shoul d r ema n secur el y wr apped unt l t est ng. Compar e r esul t s of t he unconf ned compr ess ve t est s ( 4) St ep 4. The des gn l me cont ent must be t he w t h t he cr t er a n t abl e

23 EM Apr 4 l owest l me cont ent nd cat ed. of spec mens meet ng t he st r engt h cr t er a L me and ot her add t ves. I f l me s used as a pr el m nar y 4-4. add t ve t o r educe t he or al t er t he gr adat on of a so l pr epar at or y t o t he add t on of t he pr mar y st ab l z ng agent such as b t umen or t hen t he des gn l me cont ent s t he m n mum t r eat ment l evel cement, t hat w l l ach eve t he des r ed r esul t s. For nonpl ast c and l ow- mat er al s n wh ch l me al one gener al l y s not sat sf act or y f or st ab l zat on, t he add t on of f l y ash may be needed t o pr oduce t he necessar y r eact on.

24 EM Apr 4 CHAPTER 5 STABI LI ZATI ON WI TH LI ME- CEMENT- FLY ASH ( LCF) 5-1. React on w t h so l s. St ab l zat on of coar se- gr a ned so l s hav ng l t t l e or no f nes can of t en be accompl shed by t he use of t he LCF comb nat on. Fl y ash s a pozzol an c mat er al, cons st ng ma nl y of s l con and al um num compounds t hat, when m xed w t h l me and wat er, f or ms a har dened cement t ous mass capabl e of obt a n ng h gh compr ess ve st r engt hs. Thus, l me and f l y ash n comb nat on can of t en be used successf ul l y n st ab l z ng gr anul ar mat er al s hav ng f ew f nes s nce t he f l y ash pr ov des an agent w t h wh ch t he l me can r eact. I n add t on t o l me and f l y ash, a smal l amount of por t l and cement s al so added t o accel er at e and ncr ease st r engt h ga n. ASTM C 53 pr ov des gu dance n t he sel ect on of f l y ash Su t abl e mat er al s. Types of st ab l zat on ar e coar se- gr a ned so of t he mat er al pass ng t he No. 200 m nus 40 f r act on shoul d not exceed mat er al s su t abl e f or t he LCF l s hav ng no mor e t han per cent s eve. I n add t on, t he of t he LCF cont ent. ASTM C 53 shoul d be used f or t he det er m nat on of m x pr opor t ons of t he LCF except t hat n add t on t o l me and f l y ash as nd cat ed n t he pr ocedur e, about 1 per cent Por t l and cement shoul d al so be added f or st r engt h. M n mum unconf ned compr ess ve st r engt h r equ r ement s ar e nd cat ed n t abl e 2-1. I f t est spec mens do not t hen meet st r engt h r equ r ement s, add cement n ncr ement s of 1/ 2 per cent unt l st r engt hs ar e adequat e. The t ot al quant t y of add t ves shoul d not exceed 15 per cent by we ght. I n f r ost ar eas, t he LCF m xt ur e shoul d meet t he we ght l oss cr t er a spec f ed f or cement - st ab l zed so l s. ASTM D 560 shoul d be f ol l owed except t hat t he spec mens shoul d be compact ed n accor dance w t h t he pr ocedur e descr bed n MI L- STD- 621, Met hod 0, Compact on Ef f or t Des gnat on CE- 55. For mob l zat on, t he use of ASTM D 560 may be al t er ed t o 6 cycl es of 6 hour s of f r eeze/ wet 6 hour t haw/ dr y. Per cent ages of st ab l zer sel ect ed f or use may be based on l ocal per f or mance h st or y n l eu of t hese t est s.

25 EM Apr 4 CHAPTER 6 STABI LI ZATI ON WI TH BI TUMEN 6-1. Types of b t um nous- st ab l zed so l s. a. Sand b t umen. A m xt ur e of sand and b t umen n wh ch t he sand par t cl es ar e cement ed t oget her t o pr ov de a mat er al of ncr eased st ab l t y. b. Gr avel or cr ushed aggr egat e b t umen. A m xt ur e of b t umen and a wel l - gr aded gr avel or cr ushed aggr egat e t hat, af t er compact on, pr ov des a h ghl y st abl e wat er pr oof mass of subbase or base cour se qual t y. c. B t umen l me. A m xt ur e of so l, l me, and b t umen t hat, af t er compact on, may exh b t t he char act er st cs of any of t he b t umen- t r eat ed mat er al s nd cat ed above. L me s used w t h mat er al s t hat have a h gh,. e., above So l gr adat on. The r ecommended so l gr adat ons f or subgr ade mat er al s and base or subbase cour se mat er al s ar e shown n t abl es 6-1 and 6-2, r espect vel y. Tabl e 6-1. S eve S ze 3 nch No. 4 No. 30 No. 200 Recommended Gr adat ons f or B t um nousst ab l zed Subgr ade Mat er al s Per cent Pass ng B t um nous st ab l zat on s gener al l y 6-3. Types of b t umen. ac c ompl s hed us ng asphal t cement, cut back asphal t, or asphal t emul s ons. The t ype of b t umen t o be used depends upon t he t ype of so l t o be st ab l zed, met hods of const r uct on, and weat her cond t ons. I n f r ost ar eas, t he use of t ar as a b nder shoul d be avo ded because of t s h gh- t emper at ur e suscept b l t y ; however, mat er al av a l ab l t y may Asphal t s ar e af f ec t ed t o a r equ r e t he use of t ar s n nonf r ost ar eas. l esser ext ent by t emper at ur e changes, but a gr ade of asphal t su t abl e As a gener al r ul e, t he t o t he pr eva l ng cl mat e shoul d be sel ect ed. mos t sat sf act or y r esul t s ar e obt a ned when t he most v s c ous l qu d For h gher asphal t t hat can be r ead l y m xed nt o t he so l s used. qual t y m xes n wh ch a cent r al pl ant s used, v scos t y- gr ade asphal t cement s shoul d be used. Much b t um nous st ab l zat on s per f or med n pl ace w t h t he b t umen be ng appl ed d r ect l y on t he so l or so l - aggr egat e syst em and t he m x ng and compact on oper at ons be ng For t h s t ype of const r uct on, conduct ed mmed at el y t her eaf t er.

26 EM Apr 4 Tabl e 6-2. Recommended Gr adat ons f or B t um nous- St ab l zed Base and Subbase Mat er al s 1-1/ 2- nch Max mum S eve S ze 1- nch Max mum 3/ 4- nch Max mum 1/ 2- nch Max mum nch / 4- nch / 2- nch / - nch No No No No ± No ± 7 No. 0 ± No ± / 2- nch U. S. Ar my Cor ps of Eng neer s 0

27 EM Apr l qu d asphal t s,. e., cut backs and emul s ons, ar e used. Emul s ons ar e pr ef er r ed over cut backs because of ener gy const r a nt s and pol l ut on The spec f c t ype and gr ade of b t umen w l l depend on c ont r ol ef f or t s. t he. char act er st cs of t he aggr egat e, t he t ype of const r uct on equ pment, and cl mat c cond t ons. Gener al l y, t he f ol l ow ng t ypes of b t um nous mat er al s w l l be used f or t he so l gr adat on nd cat ed :, a. Open- gr aded aggr egat e. ( 1) Rap d- and med um- c ur ng l qu d asphal t s RCand 00, and MC ( 2) Med um- s et t ng asphal t ( 3) Tar s RT- 1 and RT- 2. ( 1) Rap d- and med um- cur ng and MC- 00. ( 2) CMS- 2, no mat er al pass ng t he No. l qu d asphal t s RC- 250, Tar s RT- 1, RT- 2, RT- 3, emul s ons MS- 2, and RT- 4. c. Aggr egat e w t h a cons der abl e mat er al pass ng t he No. 200 s eve. per cent age of f ne aggr egat e and ( 1) Med um- c ur ng l qu d asphal t s MC- 250 and MC- 00. ( 2) Sl ow- cur ng l qu d asphal t s ( 3) CSS- 1h. RC- 00, Sl ow- cur ng l qu d asphal t s SC- 250 and SC- 00. ( 3) Med um- s et t ng and sl ow- set t ng asphal t SS- 1, and CSS- 1. ( 4) 250, emul s on MS- 2 and CMS- 2- b. Wel l - gr aded aggr egat e w t h l t t l e or 200 s eve. MC- 250, and MC- 70, Sl ow- set t ng asphal t emul s ons ( 4) Med um- s et t ng asphal t ( 5) Tar s RT- 3, RT- 4, SC- 250 and SC- 00. RT- 5, SS- 1, SS- 1h, CSS- 1, and emul s ons MS- 2 and CMS- 2and RT- 6. The s mpl est t ype of b t um nous Unbound aggr egat e. d. st ab l zat on s t he appl cat on of l qu d asphal t t o t he sur f ace of an For t h s t ype of oper at on, t he sl ow- and unbound aggr egat e r oad. Tar med um- c ur ng l qu d asphal t s SC- 250, MC- 70, and MC- 250 ar e used. t ypes RT- 5 and RT- 6 may be used n nonf r eez ng cl mat es. 4

28 EM Apr 4 Gu dance M x des gn. cour ses s base and subbase For subgr ade st est m at ng t he pr el used f or sel ect ed : p = 0. 02( a) f or t he des gn of b t um nous- st ab l zed cont a ned n EM and EM ab l zat on, t he f ol l ow ng equat on may be m nar y quant t y of. cut back asphal t t o be ( b) ( c) ( 0 - S) ( d) g 0 wher e : p a c S per cent cut back asphal t by per cent of m ner al aggr egat per cent of m ner al aggr egat on No. 0 s eve per cent of m ner al aggr egat on No. 200 s eve per cent of m ner al aggr egat per cent sol vent we ght of dr y aggr egat e e r et a ned on No. 50 s eve e pass ng No. 50 and r et a ned e pass ng No. 0 and r et a ned e pass ng No. 200 s eve The pr el m nar y quant t y of emul s f ed asphal t t o be used n st ab l z ng subgr ades can be det er m ned f r om t abl e 6-3. The f nal des gn cont ent of cut back or emul s f ed asphal t shoul d be sel ect ed based upon t he r esul t s of t he Mar shal l St ab l t y t est pr ocedur e The m n mum Mar shal l St ab l t y r ecommended f or ( MI L- STD- 620). subgr ades s 500 pounds. I f a so l does not show ncr eased st ab l t y when r easonabl e amount s of b t um nous mat er al s ar e added, t he gr adat on of t he so l shoul d be mod f ed or anot her t ype of b t um nous mat er al shoul d be used. Poor l y : gr aded mat er al s may be mpr oved by t he add t on of su t abl e f nes cont a n ng cons der abl e mat er al pass ng t he No. 200 s eve. The amount of b t umen r equ r ed f or a g ven so l nc r eas es w t h an ncr ease n per cent age of t he f ner s zes.

29 EM Apr 4 Tabl e 6-3. Per cent Pass ng No. 200 S eve U. S. Pounds of 50 Emul s f ed As phal t Requ r ement s Emul s f ed As phal t per 0 Pounds of Dr y Aggr egat e at Per cent Pass ng No. S eve Ar my Cor ps of Eng neer s

30 EM Apr 4 APPENDI X A PH TEST TO DETERMI NE LI ME REQUI REMENTS FOR LI ME STABI LI ZATI ON A- 1. Mat er al s. A- 2. Appar at us. L me t o be used f or a. PH met er ( t he ph met er a ph r ange of 14). b m l l l t r e c. 50- m l l l t r e d. D st l l ed wat er e. Bal ance. f. Oven. g. Mo st ur e cans. A- 3. a ( or must l ar ger ) so l st ab l zat on. be equ pped w t h an el ect r ode hav ng pl ast c bot t l es w t h scr ew- t op l ds. pl ast c beaker s. t hat s f r ee of C02. Pr ocedur e. St andar d ze t he ph met er w t h a buf f er sol ut on hav ng a ph of b. We gh t o t he near est gr am r epr esent at ve sampl es of a r - dr ed so l, pass ng t he No. 40 s eve and equal t o gr ams of oven- dr ed so l. c. Pour t he so l s c r ew- t op l ds. sampl es nt o 150- m l l l t r e pl ast c bot t l es w t h d. Add var y ng per cent ages of l me, we ght ed t o t he near est gr am, t o t he so l s. ( L me per cent ages of 0, 2, ' 3, 4, 5, 6,, and, based on t he dr y so l we ght, may be used. ) e. Thor oughl y m x so l and dr y f. Add 0 m l l l t r es of so l - l me m xt ur es. l me. d st l l ed wat er t hat s C02- f r ee t o t he Shake t he so l - l me and wat er f or a m n mum of 30 seconds g. unt l t her e s no ev dence of dr y mat er al on t he bot t om of t he bot t l e. h. Shake t he bot t l es f or 30 seconds ever y m nut es. or

31 EM Apr 4. Af t er 1 hour, m easur e t he ph. and t r ansf er par t of t he sl ur r y t o a pl ast c beaker The l owest j. Recor d t he ph f or each of t he so l - l me m xt ur es. l m e g v ng per cent of a ph of. 40 s t he per cent r equ r ed t o st ab l ze t he so l. I f t he ph does not r each. 40, t he m n mum l me cont ent g v ng t he h ghest ph s r equ r ed t o st ab l ze t he so l.