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Show Utah Governor Calvin L. Rampton recently released the results of a report entitled "An Evaluation of the Performance Per-formance of Asphalt Pavements in Utah." THE REPORT, prepared by a blue-ribbon panel of independent experts appointed appoint-ed by Governor Rampton, investigated charges of, inferior asphalt and construction con-struction techniques being used to build Utah's roads. The report concluded, that on the whole, Utah was moving mov-ing in the right direction in its asphalt road construction. ONE OUT-of-state panel member concluded that "Utah's highways measure up-favorably up-favorably with those of other states." The report noted that "the characteristics of the asphalt in question have greatly improved during the past 20 years. Many of the pavement (failures) observed represent a 'holdover' from past design and construction proce-' dures. . . The Utah Department of Transportation Transporta-tion has the expertise in their materials, research, design, construction and other technical tech-nical and administrative personnel per-sonnel to (continue to) reduce pavement deficiencies such as transverse cracking. . . " "INFERIOR" UTAH produced asphalts have often been blamed for poor pavement performance, but the panel concluded, "There is very little evidence that asphalt cements produced by American Oil Co. and Phillips Petroleum Co. have been the major contributing factor in the poor performance of dense-graded hot plant-mix pavements constructed prior to 1970." Utah asphalts, while not the best in the nation, are not the worst either, and provide an acceptable level of performance. perfor-mance. "Beginning about 1973, the asphalts produced by American and Phillips were improved by selective blending with fluxes from other sources. The present level of quality should be maintained or improved." IN MANY areas the panel was complimentary of the Utah Department of Transportation's Trans-portation's specifications and procedures. Utah's asphalt mix designs, control procedures, sub-base design and construction, and chip-sealing chip-sealing jobs all received high marks. In two major areas, however, the panel recommended recom-mended some further changes in Utah's specifications. specifica-tions. The use of softer asphalts and a change in the aggregate gradation were suggested. UTAH, LIKE many other states, began using harder asphalts during the early years of the Interstate program. The harder asphalts made the pavement more "stable" and better able to withstand the heavy beating by high speed cars and trucks. But the harder asphalts were also more "brittle" and more susceptible to cracking in cold weather. The forma tion of cracks was usually followed by the formation of chuck holes. To combat this, the panel suggested using softer asphalts. DIRECTOR OF Transportation Transpor-tation Blaine J. Kay said, "We realized several years ago that we were using too hard a grade of asphalt and we have been moving towards increasingly softer grades since then. We have achieved better performance by using the softer grades. Currently our main paving grade of asphalt is one grade harder than that recommended recommend-ed by the panel. We will investigate the feasibility of using even softer grades, but it must be recognized that the softer grades of asphalt can be more susceptible to rutting and bleeding during the warm summer months." IT WAS also recommended that Utah decrease the percentage per-centage of "fines" or small particles in the aggregate (gravel) mixed with asphalt oil to make asphalt pavement. The percentage of fines in a mix can affect both the strength and flexibility of asphalt. "We have already reduced the number of fines in our asphalt mix within the last year," said UDOT Engineer of Materials and Research Wallace J. Stephenson, "but it is still not as low as the panel recommendations. We will research this very carefully to establish a cost-benefit cost-benefit ratio for the change. "WE DO know that if we reduce the percentage of fines more, our costs for aggregate could increase. It is quite possible, though, that this increase could be adequately offset by improved pavement performance." Director Kay said, "There were numerous other technical tech-nical recommendations made. Some of them we have already implemented, some we will implement in the near future, and a few will require further study before any changes will be made. "WE ARE very happy with the panel's report. No matter what the job, there is always some way to do it even better. Sometimes it takes an outside opinion to find the areas for improvement. We are. extremely appreciative that the panel members took the time to carefully review our procedures and we welcome their suggestions. I think the end result will be even better roads for the citizens of Utah." |