This report is meant as a state of the art on utilization of solid waste material for road construction and maintenance. There are many waste materials, but in Minnesota three products are of prime interest because they are available in such large quantities. These are: Taconite Tailings, Fly Ash, and Boiler Slag
Much study has been done on some of these large volume materials. Some of the successful uses found for these products are embankment fill, subbase, base, stabilize for soil or aggregate, paving aggregate, and bituminous mix components.
This report undoubtedly is not the "last word" on the subject of solid waste utilization. Some materials or uses may have been overlooked or neglected, but it is hoped that the overall local state picture is well represented. This report has attempted to show that there are some large volume waste materials, there are bona fide uses for them, and utilization could be expanded with some effort. This also applies to lesser volume materials that sometimes aren't recognized as being usable.
This report is intended as a resource document for use by transportation analysts in comparing the energy intensities of various transportation alternatives. "Energy intensity" is defined as the energy use per unit of productive output.
Transportation accounts for a significant portion of the total energy consumption in the United States, utilizing over 25 percent of the annual total. Consequently, the energy impacts of transportation alternatives are a critical national concern. Any reduction in energy consumption which can be realized in the transportation sector will contribute substantially toward the alleviation of the U.S. energy problem.
This report presents the results of a review of long held contentions regarding driver choice of speed and reaction to speed limits. Areas of concern that were studied included influence of the roadway environment, reaction to school speed zones and reaction to warning flashers. Results of the review show that drivers do vary their speed under differing conditions, they do not react as desired to lowered speed limits or to passive signing. They do lower speeds when they see a warning flasher in conjunction with limit signs, but not as much as is requested. There was evidence too that in some zones a lower limit may result In a more hazardous situation.
New bridge decks will be designed to standards which insure a reasonably long maintenance free life. The new bridges have been grouped into three categories with a deck protective system designed to be cost effective for the anticipated exposure to de-icing chemicals in each of these categories.
A task force composed of personnel from the Offices of Bridges and Structures, Materials, Research and Standards has reviewed and analyzed existing procedures for protection of bridge decks.
The objectives of the task force were:
1. To develop policy for installation of protective systems on new bridge decks.
2. To develop policy for establishing priorities and selecting methods for contract restoration and protection of in-service bridge decks.
3. To develop policy for systematic maintenance utilizing M.H.D. forces, for the preservation of in-service bridge decks which are not being considered for contract restoration.
The objectives were set to protect the bridge deck investment in a cost-effective manner and within budget limitations.
This prospectus outlines the need for and nature of a system of freeway surveillance and control for the St. Paul-Minneapolis Metropolitan Area. Information is presented on the transportation trends in the Metropolitan Area showing heavy reliance on highway vehicular travel and indicating that capacity deficiencies will exit. The role that freeway surveillance and control may play in the development of a total transportation system is presented. Also included is information on the cost-effectiveness of various urban transportation modes.
The long-range plans and a description of the ultimate system are outlined along with a plan of implementation to develop the system in an organized manner.
In the past, the major determinant for spring load restrictions was the tested strength of the road. Since trucks are the stressing fraction of the traffic, and they will vary in volume from nearly nothing to many thousand trucks per day, this major aspect must be taken into account. Other diagnostic techniques developed recently (and are in common usage) can be used to aid the establishment of spring axle load.
In September 1978, a Mn/DOT Task Force was established to conduct an in-depth analysis of rehabilitation measures for the 5.2 mile section of l-92 (see map, page 9) continuously reinforced concrete pavement (CRCP) located between Snelling Avenue in St. Paul and the Lowry Hill Tunnel in Minneapolis. The pavement is rapidly deteriorating due to ruptures of the reinforcing steel and spalling of the driving surface. This section of highway averages 30,000 vehicles per day. The rehabilitation of this pavement will have significant impacts. during construction in terms of social and economic cost to the traffic user and public served by the facility. In addition, the magnitude of the rehabilitation will have a major impact on the financial resources of Mn/DOT.
Because of the impacts, Mn/DOT management, felt it imperative to investigate and evaluate all possible measures in terms of design, engineering, project staging, timing, and cost. This report discusses the findings of the Task Force.
The purpose of this three month study has been to determine whether it is feasible to simulate an asphalt pavement section using the elastic theory. This has been done by first obtaining samples from Investigation 183, Test Section 102 and determining the stress-strain properties of the various layers using the repeated load triaxial test under various conditions. Appropriate moduli have then been put. into an elastic layered system which is used to calculate stresses and strains within the system. The Benkelman beam deflections measured in the field have been simulated in this manner and the comparison between computed and measured deflections is used to show whether the elastic theory simulates a flexible pavement. The possibility of determining equivalencies between stabilized base courses and granular base courses are explored as are the use of other parameters for design purposes.
Ideally, the type of pavement chosen for highway construction projects is the product of an analysis resulting in the most favorable combination of economic and engineering factors expressed in terms of the lowest annual cost per mile of road. Circumstances make the analysis somewhat less than ideal because inherent in the procedure is the need to make assumptions about future maintenance and costs in order to compare alternatives over equal periods of time. This report is a critical review of the pavement selection process as practiced by the Minnesota Department of Transportation. The study was conducted by the Research and Standards Section in response to an assignment made on June 23, 1975 by the Director of Materials, Research and Standards Office who also serves as chairman of the Pavement Selection Committee. The report presents a resume' of current practice together with analysis and recommendations for improvements in the process.
