The Center for Structural Durability (CSD) explores research in the area of durable structural highway systems including ultra-high performance concrete applications, rapid construction for prestressed concrete bridges, and inspection and repair of transportation systems and bridges using remote sensing and other non-destructive inspection techniques. Structural durability related research helps state DOTs, federal agencies and industry clients achieve their performance goals of safety, mobility, and productivity of the transportation system while developing long-term solutions to improve the resiliency of our nation’s transportation structures.
Hot Mix Asphalt (HMA) has been traditionally produced at a discharge temperature of between 280°F (138°C) and 320° F (160°C), resulting in high energy (fuel) costs and generation of greenhouse gases. The goal for Warm Mix Asphalt (WMA) is to use existing HMA plants and specifications to produce quality dense graded mixtures at significantly lower temperatures. Europeans are using WMA technologies that allow the mixture to be placed at temperatures as low as 250°F (121°C). It is reported that energy savings on the order of 30%, with a corresponding reduction in CO2 emissions of 30%, are realized when WMA is used compared to conventional HMA. Although numerous studies have been conducted on WMA, only limited laboratory experiments are available and most of the current WMA laboratory test results are inconsistent and not compatible with field performance.
The main objectives of this study are: 1) review and synthesize information on the available WMA technologies; 2) measure the complex/dynamic modulus of WMA and the control mixtures (HMA) for comparison purpose and for use in mechanistic-empirical (ME) design comparison; 3) assess the rutting and fatigue potential of WMA mixtures; and 4) provide recommendation for the proper WMA for use in Michigan considering the aggregate, binder, and climatic factors.
The testing results indicated that most of the WMA has higher fatigue life and TSR which indicated WMA has better fatigue cracking and moisture damage resistant; however, the rutting potential of most of the WMA tested were higher than the control HMA. In addition, the WMA design framework was developed based on the testing results, and presented in this study to allow contractors and state agencies to successfully design WMA around the state of Michigan.
This report describes the development and establishment of a proposed Simple Performance Test (SPT) specification in order to contribute to the asphalt materials technology in the state of Michigan. The properties and characteristic of materials, performance testing of specimens, and field analyses are used in developing draft SPT specifications. These advanced and more effective specifications should significantly improve the qualities of designed and constructed hot mix asphalt (HMA) leading to improvement in pavement life in Michigan. The objectives of this study include the following: 1) using the SPT, conduct a laboratory study to measure the parameters including the dynamic modulus terms (E*/sinϕ and E*) and the flow number (Fn) for typical Michigan HMA mixtures, 2) correlate the results of the laboratory study to field performance as they relate to flexible pavement performance (rutting, fatigue, and low temperature cracking), and 3) make recommendations for the SPT criteria at specific traffic levels (e.g. E3, E10, E30), including recommendations for a draft test specification for use in Michigan. The specification criteria of dynamic modulus were developed based upon field rutting performance and contractor warranty criteria.
SPONSOR: MICHIGAN DEPARTMENT OF TRANSPORTATION (MDOT)
PI: Zhanping You
Michigan is a state with high precipitation and cold winter temperatures (wet-freeze climate). This wet-freeze climate makes the pavement system in Michigan different from many other regions. Compared to other regions with different climates, the most noticeable pavement distress in Michigan is freeze-thaw induced damage. Thermal cracking and fatigue cracking in asphalt pavements and transverse cracking and joint faulting in concrete pavement are also major forms of pavement distress. In addition, potential damage from de-icing materials and snow removal vehicles are concerns. These concerns have limited the usage of some pavement types that are widely used in other states or countries.
The success of this research project can enable MDOT to understand which best practices in other states or countries can be potentially implemented in Michigan.
The objectives of this research include:
Document best practices nationally and internationally for pavement design, pavement materials selection, construction (workmanship), and maintenance of roadway pavements in wet freeze climates that are similar to MI,
Identify barriers to implementing the best practices presently not used in MI,
Recommend the best practices that could be implemented in MI
Sponsor: Michigan Department of Environmental Quality (MIDEQ)
PI: Qingli Dai
In the recent decade, the resuse of scrap tire rubbers in concrete has attracted much interests of researchers and practitioners. The practical efforts can reduce the environmental impact. In general, the rubber-modified concrete can improve static and dynamic fracture toughness and decrease brittleness. Particularly, the mixed rubber particles (mesh size #10-#30) will introduce the uniformly distributed “elastic entrained particles”, which can release internal expansive stress due to freeze-thaw damage and chemical attack for improved durability. In addition, the surface-treated rubber particles have good bonding strength with cement paste. Continue reading “Fiber-reinforced High Performance Rubber Concrete for Concrete Structure Construction and Repair”
The objective of this award is to understand the foaming process using several foaming agents to guide us in the design of a new warm mix asphalt (WMA) technology. In the proposed project, researchers from Columbia University and Michigan Technological University will investigate three foaming agents as potential candidates, including soda as a chemical foaming agent, CO2/N2 gas and ethanol as physical blowing agents. Multiphase characterization and viscoelastic modeling studies will be conducted to investigate how the microstructure of asphalt materials evolves with time, temperatures, and proportion of material constituents, and in doing so study any differences and relative benefits from chemical vs. physical blowing agents. A single or the combination of foaming agents will be determined for optimal end-results. The fatigue strength, the long-term performance and life cycle cost of the WMA based on the foaming process will be characterized with accelerated test methods.
This project integrates state-of-the-art rheological and accelerated aging tests, thermodynamics, poromechanics, chemical changes and multi-scale modeling to identify the physical and mechanical properties of foamed asphalt materials. The proposed studies will advance the understanding of the foaming process and establish a theoretical framework to predict the material behavior for material design, which will lead to new theories and models of sustainable engineering materials in energy and environmental aspects. This project provides a unique opportunity for conducting interdisciplinary research in sustainable engineering to reduce energy consumption, greenhouse gas emission, to facilitate recycling of asphalt materials, and improve life-cycle performance. The technologies developed in this program will be rapidly transferred to industry.
The objectives of this study are the following: (1) check the quantity and quality of existing data for weather stations in Pavement Mechanistic-Empirical (ME) Design; (2) investigate the sensitivity of required pavement designs to climatic inputs; (3) determine sources of additional weather data that can be utilized in Pavement ME Design; (4) determine where additional weather stations would be beneficial; (5) run quality checks on additional weather data and weather stations and place into the correct format for Pavement ME Design; and (6) develop a procedure to choose weather data for virtual stations for gap areas where there is no actual weather station.
The mission of the TMRC is to provide expertise and facilities to support the Michigan Department of Transportation (MDOT)’s infrastructure materials engineering needs through technical services and engineering support. The TMRC also provides education and outreach to transportation officials in the state.
The center activities for 2016 provide a continuation of the past activities of the TMRC. The main center activities will continue to be technical support through material testing and analysis in conjunction with our innovative research investigations, education and outreach in support of MDOT’s mission.
The efforts of the TMRC are divided into two components; Core Services and Supplemental Services.
Core Services include education, research support and communications. Education activities include employment of both undergraduate and graduate students on TMRC projects and provide lectures on TMRC projects to a wide range of audiences that interact with MDOT or other transportation related organizations. Research support provides the administration of the TMRC contract and dissemination of TMRC project results to MDOT and at national meetings such as the Transportation Research Board (TRB). Communications include conveyance of the TMRC’s analysis, forensic evaluations and recommendations for field implementation through a written report and may be published in peer-reviewed journals or via direct meetings with MDOT personnel.
Supplemental services are those associated with specific technical projects and investigations as specified by the MDOT project manager through a formal request process.
Sponsor: Michigan Tech Transportation Institute (MTTI)
PI: Zhen Liu, Qingli Dai
The air void size distribution has significant impacts on mechanical, thermal and transport properties of concrete and long-term durability such as freeze-thaw resistance. Measuring the characteristics of air voids in concrete (especially at early-ages) is thus very important in assessing its long-term durability. Nondestructive ultrasonic technique will be developed for potential concrete mixture quality control both in lab and field applications.
1. Develop ultrasonic air void size distribution measurement techniques for hardened air-entrained concrete and evaluate the accuracy with ASTM C 457 measurements
2. Develop ultrasonic air void size distribution measurement techniques for early-age air-entrained concrete and evaluate the accuracy with the ASTM C 457 measurements
3. Develop the testing procedures and data processing tools for potential field applications
1. Prepare air-entrained concrete samples with/without internal curing reservoirs (using light-weight fine aggregates) for air void distribution measurements
2. Design the ultrasonic measurement system for both hardened and early-age concrete sample measurements and develop the signal processing programs for the air void distribution evaluation of both types of samples
3. Evaluate the measurement accuracy by comparing with RapidAir ASTM C 457 and propose the testing procedures for potential field mixture quality control