Downloaded from https://www.everyspec.com 14rL-sTD-6192 1. Smm Tus standardeatablishm criteriafor the classificationof soilsby the Unified S00 Claz6ificationSyztem, includingclazaificatioaof frozen zoilz. me iszuea of the follouins doamanta in effect 08 date of Iwdta%ioo for bide tom a part of tbia staadard to t& ~ epacified hreilt: Qov2mmTAL STAmLRm Uilitcq Nm-sTD421 - Test Mthod for PavwmentSubgrada,Subbeee,and 2eae-CourseNaterial. 3.1 Clazaiflcationeyztem. Soile se3.&n e.xietin nature separately00 mad, gravel,orauyother ai@ocmponent butereuzually fouudae mixtures vith varyinsproportion of particles of di~ sizes. Each c5pcment ccdmibutea ita C~rietics to the miztu?e.
Tlm unified Cleaaifieatim syztem iz baaed m those characteristics of the soil which indicatehou it G will behave 02 a coastruotitamterial. This zyateala a modification of the orisiaal.Caee2rmde Airfield ClazniflcationSyztem. The followia2 propertieshave bean found ztoetuzefulIapredioting howamiluillbehava 22 a comtmctim ~el ml ccmeequently ‘fore tln besia of * Unified SY8M. The propertiescan be ~ with very simpleteats cad, with experience,cm be eetimateduith sme eccuryy: Pammtuos of gravel, sand, MM fines (fimcticm peeing Ho. 2Q0 sieve). Sham or the grain-alze dietributica curve. Plasticity ead mnpreaaibility chareetaxtatica.
\ Inthe Unified S9ztam, thet30illa sivenaaame wbiohiahteadadto baa short description,md a lat. symbol which cmziate of X lattara indi- cating its principal~atica. T&ble I a~zea the zyztem,giving thanllmM, letter zymnma,alld2eneral infomatial -the mile. Iatha unified System, aoile are dividedinto coerze-2mMnad d fins-srdmed ma- teriale. m Cmvmieme ~owti=~m==t =Msawa~~ Bo.200sieva ietemadc~Srdned, Oulauyzadl haviagaorethzam perceatpeaeing the Mo.200sievo iatemad fiae grainad. 1