. Engineering and Contracting . ling approximately a mile in length. The material em-ployed was Willite, which used as the sole aggregate thelight, drifting sand, a trifle loamy, found along the highway,and a binder of asphalt treated with copper sulphate; thisbinder being the special feature of this kind of dune sand used, when subjected to sieve analysis, testedas follows: Percent. Passing 200 mesh 6 Pas 100 ireFh and retained en 200 4S Pa.^sing SO mesh and retained on 100 28 Passing fiO mesh and retained on SO 14 Passing 10 mesh and retained on 60 Passing 20 mesh and
. Engineering and Contracting . ling approximately a mile in length. The material em-ployed was Willite, which used as the sole aggregate thelight, drifting sand, a trifle loamy, found along the highway,and a binder of asphalt treated with copper sulphate; thisbinder being the special feature of this kind of dune sand used, when subjected to sieve analysis, testedas follows: Percent. Passing 200 mesh 6 Pas 100 ireFh and retained en 200 4S Pa.^sing SO mesh and retained on 100 28 Passing fiO mesh and retained on SO 14 Passing 10 mesh and retained on 60 Passing 20 mesh and retained on 40 Retained on 10 mesh No broken stone was used; and the only water used wasfor the steam boilers of the road roller and asphalt plantand for the men and animals on the job. The mixture con-sisted of the following, per 747-lb. box: Lb. Sand 650 .\ ?;??> Ijimestone dust 211 Sulphate 2 No hauling was required for 87 per cent of the material,the sand being dragged to the mixing plant by means of. Constructing Fresno scraper. The cost of the mineral aggregate, deliveredin the mixer, was figured by the contractors cost accountantat less than 40 ct. a cubic yard. The pavement was made 5 in. thick where laid directlyon the dirt surface of the unpaved road, and a 2-in. surfac-ing was laid on the old macadam. Method of Construction.—The mixing was done in a Cum--mer portable road asphalt paving plant, slightly modified, sothat the mixing bucket was somewhat larger, to admit ofthe effervescence which takes place when the copper sul- phate is added to the heated asphalt. The heated asphaltis delivered by force pump, the sand is handled by auto-matic conveyor, and delivery to truck is made automaticallyon completion to the mix by opening the bottom of the pugmixer. The material was loaded onto the trucks at about320° F. On this job, after the hot material had been spread, allrolling took place lengthwise of the highway, it being im-possible to undertake the
Size: 2267px × 1103px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, bookpublisherchicago, bookyear19
