Texas Transportation Institute

Knapp, K. Rao, K. Cratvford, J. and Krammes, R. (1994). The Use and EvnlunCion of TrunsporCuCion Control Measures. Research Report 1279-6. Texas Transportation Institute. Texas Federal Highway Administration and Texas Dcpaixnient of Transportation. 

Schrank, D. and Lomax, T. (2005). The 2005 Urban Mobility Report. Texas Transportation Institute, Texas A M University System. 

The Texas Transportation Institute has just completed a very extensive two year FHWA sponsored program to look into other aspects of safety and environmental impact of sulfur-asphalt construction [53]. A number of typical sulfur-asphalt and sulfur-concrete paving systems were evaluated to assess their potential environmental impact and establish safety considerations relative to their formulation, construction and maintenance. The environmental impact was investigated from the formulation stages, through weathering, and included considerations of simulated fires and chemical spills. 

Other Work. In addition to the work conducted by Shell Canada Limited, a number of studies with similar materials have been conducted by the Texas Transportation Institute (29), the U.S. Bureau of Mines (30) and the National Research Council of Canada, Dept, of Building Research (31.). 

Highway District 11 is located in East Texas, and the area does not have an abundant supply of conventional aggregates. Of the materials available locally, sand is the most plentiful. These local sands were first combined with asphalt in a hot-mix plant in 1962 and were evaluated on U.S. and State highways. From this experience, it was concluded that hot-hand asphalts merited consideration as base materials. Quite often two sands (usually 100% passing the 40 sieve) are combined to obtain the proper gradation. When it was subsequently learned that the Texas Transportation Institute (13) was evaluating the sulfur-asphalt binders, efforts were initiated to field test these materials. 

Sulfur-asphalt binders can be prepared by various mechanical means. One conventional method is to combine liquid sulfur and asphalt at 285°-300°F in a Gifford Wood colloid mill. A rotor stator gap setting of 0.02 in. at 7000 rpm for 8 min will prepare satisfactory emulsions. This emulsion is immediately mixed with preheated aggregate. The laboratory binder was prepared by TTI (Texas Transportation Institute) scientists in cooperation with SNPA (Societe Nationale des Petroles d Aquitaine) scientists and is believed to be comparable with the binders prepared by the turbine in the field trials. The need for dispersing sulfur in the asphalt is discussed by Garrigues (9) and by Kennepohl et al., Deme, and McBee et al. elsewhere in this volume. 

The test sections were not opened to regular traffic until June 1976 therefore they have been under traffic for only 10 months as of this report. A preliminary series of samples was taken one month after the test sections were completed (October 1975), a second series soon after the sections were opened to traffic (August 1976), and a third series of samples in April 1977. Additional test series are planned at six-month intervals until at least six series of data are obtained. The results of the preliminary and secondary testing phases have been reported by Texas Transportation Institute (16) and are summarized in Table V. 

The author wishes to acknowledge the assistance of Frank D. Galla-way, District Engineer (deceased) and appreciated his confidence that all organizations could accomplish their tasks within the needed time frame. We wish also to thank especially Bob M. Gallaway, Texas Transportation Institute, and H. L. Fike and J. O. Izatt, The Sulphur Institute, for their contributions. 

The contributions of the Federal Highway Administration, Moore Brothers Construction Co., Societe Nationale des Petroles d Aquitaine, Texas Transportation Institute, U.S. Bureau of Mines, Texasgulf, Inc., Robertson Tank Lines, Inc., and the Sulphur Institute were greatly appreciated. 

Trials, Texas Transportation Institute, Interim Reports 512-1, Study No. 1-10-75-512 (January 1976). 

The experimental data correlated quite well with those computed using the Rule of Mixtures. The computed values are given in parentheses in Table VII. The Thermopave S-A-S mixture (80.5 6 13.5) had a thermal expansion coefficient of 29.3 X 10"6 in./in.-°C which is about 30% higher than that of the A/C material used for comparison. This difference could have a significant effect on the stresses developed at the interfaces between adjacent layers of A/C and sulfur-asphalt mixtures. At this writing a more in-depth evaluation of the effects of the missmatch in thermal properties is in progress at the Texas Transportation Institute. 

McKerall WC, Ledbetter WB, Teague DJ (1982) Analysis of fly ashes produced in Texas. Texas Transportation Institute, Research Report No 240-1, Texas A M University, College Station, TX, p 382... 

Lowery, L. et al. 1969. Pile Driving Analysis State of the Art, Research Report 33-13 (final), Texas Transportation Institute, College Station, TX. 

TTI (Texas Transportation Institute). 2001. The 2001 Urban Mobility Study. College Station, Texas Texas Transportation Institute. 

Chowdhury, A., Button, J. W., Lytton, R. L. (2009). Tests of HMA overlays using geosynthetics to reduce reflection cracking. Texas Texas Transportation Institute. 

Urban Mobility Information from the Texas Transportation Institute (TTI) http //mobility. tamu.edu/ (accessed September 15,2010) provides information and resources about traffic monitoring and congestion, with emphasis on the analysis of traffic data. 

UUman, G.L. and Rose, E.R. 2004. Effectiveness of dynamic speed display signs (DSDS) in permanent apphcations. Project Summary Report 0-4475-S. Texas Transportation Institute. The Texas A M University System. TTI.PSR0401.0304.575. 

Texas Transportation Institute, Texas A M University, College Station, TX. 

A full scale test involving actual 55 gal drums arranged in the pattern shown in Fig. 12.17 was performed at the Texas Transportation Institute. The initial car speed was 52.5 mph and the weight of the car was 3,360 pounds. The displacement-time curve for the model test is shown in Fig. 12.19 together with that for the prototype test adjusted to take care of differences in scale. The two curves are seen to be practically identical. At the same time, the motions of the model drums resembled those of the prototype drums in all respects, including a wave that propagated forward from drum to drum and the sidewise motion of the drums. 

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