Southern good roads . und(iul)tedlybe given to the mixing method, but its eost is usuallysomewhat greater, and for this reason it has not beengenerally adopted. The penetration method consists in puunug hot bitu-men upon the upper course of stone which has beenwell rolled and partially filled with clean stone chipsnot smaller than 1 o inch in diameter. The lower courseshoidd be firmly consolidated and its voids well filledwith fiue material before the upper course is laid, inorder to prevent the hot bitumen from running throughto the road lied. Application is made of approximate-ly one and one
Southern good roads . und(iul)tedlybe given to the mixing method, but its eost is usuallysomewhat greater, and for this reason it has not beengenerally adopted. The penetration method consists in puunug hot bitu-men upon the upper course of stone which has beenwell rolled and partially filled with clean stone chipsnot smaller than 1 o inch in diameter. The lower courseshoidd be firmly consolidated and its voids well filledwith fiue material before the upper course is laid, inorder to prevent the hot bitumen from running throughto the road lied. Application is made of approximate-ly one and one-lialf gallons per square yard, since theobject is to use enough to thoroughly coat the upi^ercourse of stone. The surface is then painted with hotbitumen at the rate of not over one-half gallon persquare yard, and clean sand, or stone chips free fromdust spread on in sufficient quantity to fill the surfacevoids and take up all excess of bitumen, after wliiclithe road is consolidaled and ma<le smontli by La Roche Avenue. Savannah]Auta]Cuurse After this it is advisable to close the road to traffic fora day or two in order to allow it to set. The principal disadvantages of this method are asfollows: (1) It is almost impossible to obtain an abso-lutel^• uniform distrilnition of the bitumen. Tliis re-sults in the aceuDuilation of the binder in pockets whichare apt to produce soft spots, and in some portions ofthe road the individual stones are not sufficiently wellcovered to produce a satisfactory bond. (2) It is nec-essary to use more liifumen than is actually required tocoat the road stone and l)ond them together. (3) It isdifficult and sometimes impossible employ a bitumen ofsufficieut original c msisteiK-y to pro<lui-e a satisfactorybond, owing to the fait thai sm-li bilumcns congealtoo rapidly when ajijilicd to culd stone to insure a prop-er penetration. The bitumen must, therefore, havethe propertx- of aciiuiring the rigid consistency afterapplication. On t
Size: 1983px × 1261px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorvarnerhe, bookcentury1900, bookdecade1910, bookyear1910
