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Show OBSERVED ROAD TEST ON MSI B. P. E. Engineer Spends GO I Days Watching " Steel Firm's Experiments J R P Mitchell, highway engineer, D. S. bureau of public roads, with brad i quarters in Ogden, has Just returned from a 60 day assignment as an ob 1 server for the bureau of public roads, on ilie highway tests at Pittsburg. Ca These tests were inaugurated and carried on by a steel company of Pittsburg, Pitts-burg, under ihr direction of their engi-; neer Lloyd Aldrich. with the prima r, lobject of demonstrating the superior-' Hy of a heavily reinforced concrete pnvi--ment over any other type A high Way was built in the form of an oval,' the paement being 18 feet wide and 1370 feet long, containing thirteen d If -ferent types of concrete pavement both plain and reinforced. The- paYe ment was laid on an adobe subgrade. tho site being so selected that the sub grade conditions under each section would be as nearly uniform as possible and at the same time give one of the worst conditions encountered In high-, way construction. Traffic was started on November 9. with 35 trucks, each loaded to a total weight of 14,500 pounds, with the Idea of continuing this traffic until as many of the sections as possible were completely com-pletely destroyed. Traffic was continued contin-ued with but few interruptions until 1 January 28, the loads being increased from time to time until the weight of the trucks varied from 2. 500 to 27,-000 27,-000 pounds On January 28 operations were suspended to give the subgrade a chance to dry out and tests probably will not be continued unlil about June 1. At the close of traffic on January 28 a total of 3.668.100 ions had passed over the highway, the trucks had mn about 96.000 miles, making in all about 96.000 miles, about 370,000 circuits of the track. At this time four of tho 13 sections might be con sidered as totally destroyed. The other nine are still in fairly good condition although all show more or less damage dam-age from the heavy traffic to which Ihev have heen rii hie.-l td The expenses of the tests have been paid by the steel company, assisted t oa slight extent by donations from the California stale highway depart ment, the Auto Club of Southern Call fornia and the U. S. bureau of public roads. While the results to date have not been all that the steel company de- sired, much interesting and valuable I informal lou has bee.i obtained. Mr Mitchell said. i rr |