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Show 1 DEFINITION OF ROAD TERMS H List of Technical Names Taken From H the Program of the Canadian H Good Roads Congress. H With the progress of roud building B there has come Into use u number of H terms more or less technical, but H which should be well known. The fol- H lowing list Is from the program of the B Oanudlun Good Itoads cougresa : H Aggregutc. The mineral material, H such as sand, gravel, shells, slag, or H broken stone, or combinations thereof, H with which the cement or the bltuuilu- H ouh materlul Is iulxetl to form a mor- H tar or concrete. Fine uggrogute may H be considered as the mineral Inert ma- H terlal which will puss a one-fourth- V Inch screen, and coarse aggregate the H material which will not puss u one- H fourth-Inch screen.. H , tilnclof. (1) A foreign or fine mute- H rial introduced Into the mineral por- H lion of the weurlng surface for the H purpose of usslstlng the road material H to retain Its Integrity under stress, us H well as, perhaps, to aid In Its tlrst H construction. (2) The course, In n H sheet asphalt pavement, frcucutly H used between the concrete foundation H and the sheet asphalt mixture of H graded sand and asphalt cement. H llond. The combined action of In- H ertla, friction, and of the forces ot H adhesion and cohesion which helps the BBfl separate particles composing a crust BjBM or pavement in i c.siist separation under BjBlJ stress. Mechanical bond Is the bond BjBjJ produced almost wholly In u well -built BjBfl broken-stone mucudum road, by the BBB interlocking of uugulur frugments of BjBfl Btone and the subsequent filling of the BjBjJ remaining Interstices with the finer BBB BjBjJ Water Hound. Komlcd with the uld BBB of BBB Cement. An adhesive substance BBB used for uniting particles of other ma- BBB terlals to each other. Ordinarily ap- BjBS piled only to culclned "cement rock," BjBjJ or to itrtiflclally prepared calcined BBB nnd ground mixtures of limestone ami BBB rdiiclnus materials. Sometimes used to BBl designate bituminous binder used In B bituminous pavements, vheti the ex- BBV presslon "bituminous cement" (q. v.) BjBjB Is understood to be meant. BAB Cement Concrete. An Intimate mix- BY ture of gravel, shell, slag or broken BjBjB stone particles with certain propor- BBB tions of sand or similar imiterlal, ee BB-t meiit and water, made previous to BBs B&B Course. One or more layers of road BB material spread and compacted sopn- H rutcly for the formation of the road or H pavement. Courses are usually re- H ferred to In tin order of their laying, HB as first course, second course, third BjB oursc, etc. Also a single row of BBg blocks' in a pavement. BjBJ Crown. The rise In cross-section BBl from the lowest to the highest part ot BjBfl the tlulshed roadway. It may be u- BJ pressed either as so many Inches (or BBl tenths of u foot), or us a rate per loot BBB of distance from side to center, that BBl ll, "the crown Is four Inehes," or "the BjBJ crown Is one-half Inch to the foot." |