ST9801-CS000404Sent by: FREESE & NTOHOLS 214~2565 04/12/00 11~AM Job 898 Page 2/2
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Rone ng ineers
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R,,me l,'.epor'[
Mr, K. evin Yomlg,
1701 North Market Street
Smtc 500 LB 51
DaLlas, Texas 75202
R.c: Coppcll Road, Coppell, Texas
Dear Sir:
With regard to subgrade preparatton the quesmm has been raised as to thc
acivisability of using a sectmn of a non-fUne stabihzed subgrade willi a concrclc
sccm)n of c~ght roches comprised o/' 5,5 sacks of cement per yard versus a lime
stabilized subgrade with a seven inch concrete scctton comprised of five ~mclcs
cement per yard. It :s our opimon the eight-tach. 5.5 sack ~eclion is supcri,)r
The added one-half sack ',viii translate to higher tellslic strength ,,vhtci~ has
in pavement pertbrtuance. The additional inch in scclion w:il add years to thc
sm-viccabtc liik of the pavement given a constant cycizc
Even though ;kc subgradc ts not slabilized. ~I. shmzid st~ll be ~C;l/'il'icti LO thc
.six~mch dcpd~ and rccompactcd at proper lTlOlStttI'C arid dCl/Sll'y, ,.~ddlll(>l%l[}x.
m prudcnl: practice :o seal '&c concrete at. its joints am! ai(qlg atlV Cl'aC!4s IhLtl IllU'.
occm. One advantage: of l. ime-stabilizatlon is that :t provMcs ;m added
o[' protection agalllSt loss o[' subgradc strength duc [o ',:[illlri.l.t(~[[ C01'1~.~1110115, II'
pavcmcm is maintained, such that cracks are scaled, the possd>lhly of saturatm~::~
the subgrade is mimmized.
You posed another quest]on as to thc meaning o.f "non-plasltc", Wc c(,)llsid~l" l:ha~
term as precise, that is, we could not measure a plasticity m a part!ctdar soil, Wc
wdt repo~ a plasticiw index, however low, if it can be measured. Obviously
m:)n*plastic material is substantially devoid of clay. thus ~t is a gravel. 5and or silt
Regards,
Charles J. 'l;~a~Y, P.~;
Senior ConsultantJ
Scarer (]eotechnicaJ [?:ngtneer