The Bridge Investigations Unit plans and conducts research and development studies related to the structural materials and components of bridges and other transportation structures. The principal focus of structural investigations is how structural materials influence the behavior and performance of the bridge or structure.

Studies involve development of advanced materials and alloys; such as, fibrous concrete, structural steels with improved toughness and weldability, thermally sprayed coatings, and composites to improve properties or durability. The interaction between design geometry, fabrication and welding procedures, joining methods for assembly, and structural materials are studied in-depth by this Unit. Investigations of failure, prediction of life cycle, and measurement of degradation of existing structures and component materials also have high priority.

Investigations consist of field and laboratory studies; including intensive interaction with material suppliers, consultants, and academia. Depending on the nature of the problem or aims of the study; investigations are coordinated with the various Districts of the Department, the Bureau of Bridges and Structures, the Bureau of Construction, the City of Chicago, or other Local, State, or Federal agencies.

The Bridge Investigations Unit also proposes and conducts studies of a design nature from a material and durability viewpoint. Typical studies include design of advanced bridge decks, extending the life of existing movable bridge designs; and durability studies involving fatigue, stress analysis, corrosion resistance of various details, and the application of newer alloys into bridge design.

PAVEMENT TECHNOLOGY UNIT

The Pavement Technology Unit conducts studies and provides services related to the physical components of pavements and highways. The Unit’s activities involve four major areas: Pavement Management, Structural Properties, Surface Properties, and Technical Assistance and Studies.

The Pavement Management Sub-Unit concentrates on developing outputs and tools for use in the management of pavement infrastructure. The Unit maintains the Illinois Pavement Feedback System (IPFS); a highly detailed data base of inventory, condition, and performance history of the interstate system.

The Structural Properties Sub-Unit primarily concentrates on the load carrying capacity of the pavement. Through the use of the Department’s Falling Weight Deflectometer (FWD); deflection data are gathered for conducting experimental analysis, determining overlay thickness for flexible pavements, and recommending rehabilitation strategies.

The Surface Properties Sub-Unit concentrates on the physical properties of the pavement/tire interface. Items of data collected and analyzed are friction, rut depth, ride quality, and visual condition. These data are obtained by use of the Department’s friction trailers, and video inspection vehicles.

The Technical Assistance and Studies Sub-Unit deals with service requests; such as, instrumentation of pavements/structures, overweight analysis, rehabilitation advice, and studies and solutions of unique pavement problems. A number of studies are assigned to the Pavement Technology Unit due to its testing equipment, expertise in the area, and ability to fabricate test device components.

PRODUCTS EVALUATION UNIT

The stated mission of the Products Evaluation Unit is the evaluation and development of new products, materials, and processes which appear to have potential for improvements in highway construction, maintenance, and operations. Field evaluation of new items is stressed as a particularly important activity. It is expected that evaluation and development studies will produce usable information much faster than the more fundamental, relatively long-term projects carried out at the Universities.

One of the more important functions of the Products Evaluation Unit is its one stop service to vendors. Before this unit was established, manufacturers’ representatives and others with something new to offer the Department were hard pressed to find the proper office or person to present their proposals to, and were often shunted from one office or person to another. They now have a clearinghouse where they can be heard regardless of the nature of the new product. This is good for both the vendor and the Department. Department administrators are pleased to be able to quickly refer vendors to the Products Evaluation Unit. Most vendors soon learn that approaching District or Bureau offices will result only in immediate referral to the Products Evaluation Unit. Now, most vendors approach the Products Evaluation Unit directly.

The Products Evaluation Unit and the Illinois Highway Development Council work together in making the final decision on whether or not a product is approved. The Products Evaluation Unit selects products to evaluate, conducts a pre-investigation of each product to be taken to the Council, conducts laboratory and field tests, prepares reports on product evaluations, and prepares any specifications or standard changes necessary to get approved products into use. The Council studies the information and recommendation provided by the Products Evaluation Unit on each product, and makes a decision. The Council may approve field testing of relatively new and untried products to determine their applicability for IDOT use. The Engineer of Products Evaluation calls and conducts the Council meetings, and forwards Council decisions of a sensitive nature to the Director of Highways for his concurrence. The Products Evaluation Unit, as the secretariat for the Council, is responsible for all communications, reports, implementation documents, and dissemination of news of Council actions.

The current system for products evaluation treats this endeavor as a full time activity. New products are aggressively sought out, and product evaluations are conducted by professional engineers who have extensive materials knowledge and who are experienced in evaluating products. Investigations of uniform high quality produce usable results, which are then implemented. Another advantage accrues from accept-reject decisions being made by the multi-disciplinary Illinois Highway Development Council. This assures a broad perspective and maximum benefits, while minimizing chances for error. A third major advantage is the one-stop service, which benefits both vendors and IDOT management. The vendors have a focal point where they will be given an objective hearing, and the managers have a place to which vendors can be referred if they approach the Director’s office, or a District or Bureau office. A fourth advantage of the current system is that news of new product developments, product evaluation results, and product approvals is now quickly circulated throughout the Department and to highway officials in local road agencies throughout the state. This has resulted in increased willingness of individuals to cooperate in evaluation activities, and in speedier and wider use of product evaluation results.

TECHNICAL SERVICES UNIT

The Technical Services Unit provides the vital link between research and engineering practice. The Unit is responsible for providing rapid solutions to operational problems, technology transfer, and pavement design and materials expertise. Problems encountered by the Unit are complex and highly technical, and generally cannot be solved with technical expertise available elsewhere in the Department. The Technical Services Unit is divided into three Sub-Units: Design and Materials Technology; Research Implementation; and Research Coordination.

The Design and Materials Technology Sub-Unit is responsible for searching out new design and materials technology; and transforming research findings into Department policies, methods, and specifications. This Sub-Unit influences design policy by investigating pavement structural design details, solving specific pavement design problems, developing recommendations for updating the "Pavement Design" portion of the Department's Design Manual, and investigating the constructibility and early field performance of new technology. The Sub-Unit also conducts special materials investigations, and develops solutions for specific material problems.

The Research Implementation Sub-Unit acts as a liaison between the Research Section, Test Section, and other segments of the Department. To implement research findings, the Research Implementation Sub-Unit reviews research and technology developed by others (in-house and outside the Department); assesses the validity of the findings; and transforms the new technology into procedures, policies, and specifications which can be evaluated through field application. The Sub-Unit functions as a conduit for deploying these procedures, policies, and specifications (developed out of research conclusions) into IDOT construction projects. The Sub-Unit evaluates how readily theses policies, procedures, and specifications are incorporated into IDOT projects by monitoring compliance, and making recommendations for improvements when necessary. This Sub-Unit also recommends solutions to specific new research implementation problems.

The Research Coordination Sub-Unit is responsible for the technology transfer activities of the Bureau. This includes preparation of the annual National Cooperative Highway Research Program (NCHRP) Problem Statement solicitation, second stage submittals, and other associated activities. The Sub-Unit prepares research work, and coordinates studies conducted outside the Physical Research Section. Liaison is maintained with the FHWA to ensure compliance with Federal policies and procedures. The Sub-Unit provides guidance, and reviews projects for compliance with Departmental and contract agreements. The Sub-Unit prepares the budget for studies contracted to outside agencies, and submits the budget to the Engineer of Physical Research for inclusion in the overall program.