EAGER: Using Nonmetals Separated from E-Waste and Waste Plastic Bags in Improving the Mechanical Properties of Asphalt Materials

Sponsor: National Science Foundation

PI: Zhanping You

The objective of this EAGER project is to investigate the possibility of improving the mechanical properties of asphalt materials with the use of nonmetals separated from E-waste (e.g., computers, monitors, keyboard, cameras, TVs, etc.) and waste plastic bags (e.g., grocery bags). E-waste and waste plastic bags are recycled materials that have potential to be used in asphalt materials. The research work will include shredding of the non-metallic separations and waste plastic bags into powders and particles, mixing the powder-like polymers and particles to modify selected asphalt materials in the laboratory, and evaluation of the mechanical properties of the modified asphalt.

Through its integrated research and educational plan, this project will advance discovery and understanding of infrastructural materials, while promoting teaching, training, and learning – impacting underrepresented high school students and teachers, undergraduate and graduate students, and professionals from industry and the government. This project will directly benefit society through improved transportation systems and lower infrastructure costs. The project also leads to collaborative efforts with a historically black Carnegie doctoral/research intensive public institution, Jackson State University.

Zhanping You
Zhanping You

Field Evaluation of Built-in Curling Levels of Rigid Pavements

Sponsor: Minnesota Department of Transportation

PI: Jacob Hiller

This project assesses the mechanisms and methods to assess built-in curling of jointed plain concrete pavements. Through the use of literature review or previous work, material, geometric, restraint, curing and local ambient relative humidity were found to be factors affecting both construction curl and drying shrinkage, leading to built-in curl of concrete slabs. Through the extensive use of a finite element program, an artificial neural network (ANN) was developed to backcalculate the built-in curl of an in-service concrete slab using falling-weight deflectometer testing for a variety of parameters. This ANN was used to evaluate existing concrete test cells at the MnROAD facility. In addition to non-destructive evaluations, significant studies into surface profiling of these same test cells was conducted to evaluate the most accurate and simplified method for evaluating built-in curl. While the nondestructive ANN method evaluates the interaction of the concrete slab with the underlying layers, the surface profiling method does not directly reflect this interaction, but instead gives an understand of the slab’s curvature at the surface. Comparisons between these methods as well as between numerous different surface profiling methods were conducted.

Jacob Hiller
Jacob Hiller

Method for Coating Mineral Granules to Improve Bonding to Hydrocarbon-based Substrate and Coloring of Same

Sponsor: University of Michigan – MI Initiative for Innovation and Entrepreneurship

PI: Ralph Hodek

Provided are compositions comprising stamp sand granules embedded in asphalt, where the stamp sand granules comprise a silane coating. Additionally provided are methods of making a silane-coated stamp sand, the methods comprising combining stamp sand granules and a silane solution to form a mixture and drying the mixture. Additionally provided are methods of  covering a surface, the methods comprising combining silane-coated particles and asphalt to provide a mixture and distributing the mixture on the surface.

Ralph J. Hodek
Ralph J. Hodek

 

Evaluation of Concrete Pavements with Materials-Related Distress

Sponsor: Michigan Department of Transportation

PI: Lawrence Sutter

An evaluation of cores sampled from six concrete pavements was performed. Factors contributing to pavement distress observed in the field were determined, including expansive alkali-silica reactivity and freeze-thaw deterioration related to poor entrained air-void parameters. A laboratory study to investigate the role of alkali-silica reactivity through accelerated mortar bar and concrete prism testing was proposed.

A copy of this report and its appendices can be found on the Michigan Department of Transportation website.

Lawrence Sutter
Lawrence Sutter

Reduction of Minimum Required Weight of Cementitious Materials in WisDOT Concrete Mixes

Sponsor: Wisconsin Department of Transportation

PI: Lawrence Sutter

This project was designed to explore the feasibility of lowering the cementitious materials content (CMC) used in Wisconsin concrete pavement construction. The cementitious materials studied included portland cement, fly ash, and ground granulated blast furnace slag. For the first phase, mixtures were prepared using the current WisDOT aggregate grading specification. For the second phase, mixtures were prepared using an optimized (e.g. Shilstone) gradation. A variety of tests for fresh and hardened concrete were conducted to determine the viability of low CMC mixtures for use in concrete pavement.

The research resulted in several successful low CMC concrete mixtures in terms of workability, strength, and durability. Many unsuccessful low CMC concrete mixtures were also produced. The analysis of the data suggests a practical minimum CMC of 5.0 sacks/yd³ for concrete. However, successful mixtures containing fly ash were achieved at the CMC levels of 4.0 sacks/yd³ and 4.5 sacks/yd³ . The same minimum CMC limits were established in both the first and second phases of the research, regardless of the change in aggregate gradation.

Lawrence Sutter
Lawrence Sutter

Investigation of Portland Cement Concrete Exposed to Automated Deicing Solutions on Colorado’s Bridge Decks

Sponsor: Transportation Research Board

PI: Karl Peterson

The Colorado Department of Transportation (CDOT) has identified potential performance problems in some portland cement concrete (PCC) bridge decks and approach slabs in the form of pattern surface cracking, spalling, and joint/crack deterioration, which are suspected to be materials-related distress (MRD). External factors, such as the use of deicing/anti-icing chemials, have the potential to initiate and increase the reate and magnitude of deterioration due to MRD, thereby shortening the life of the structure.

This paper details the results of a study conducted to investigate whether the application of highly concentrated deicer solutions through fixed automated spray technology (FAST) automated bridge deck deicing/anti-icing systems is disproportionately contributing to the deterioration of PCC bridge decks and adjacent concrete approach slabs in Colorado and whether the mitigation strategies being employed by CDOT are addressing the problem. The approach to this investigation involved the use of visual inspection techniques, materials sampling, and the evaluation of the sampled concrete using petrographic methods.

In the bridges studied, the concrete evaluated appears to be sufficiently resistant to damage from the intrusion of deicer chemicals, though where full-depth cracking was present, obvious signs of movement of moisture and deicers through the deck were observed in addition, some initial signs of possible chemical deicer attack were noted, and continued exposure to highly concentrated deicers may contribute to long-term durability concerns. However, the use of polymer-modified asphalt/fabric membranes in conjunction with a hot mix asphalt (HMA) overlay appears to be very effective in preventing the ingress of chlorides into the underlying concrete deck.

 

Using Nonmetals Separated from E-Waste in Improving the Mechanical Properties of Asphalt Materials

Sponsor: University of Michigan – Michigan Space Grant Consortium

PI: Baron Colbert

Increasing quantities of plastics and electronic waste materials are placing a burden on the environment due to the rapid production of new electronic devices. Currently, there is a mandate for the transportation industry to produce roads and highways more economically, that are environmentally conscientious, and are sustainable. The mandate has resulted in an opportunity to implement electronic waste materials within asphalt binders. Successful implementation of these materials require a better understanding of the performance between modified asphalt binders and mixtures under variable temperature and loading conditions. This investigation explored the performance of modifying asphalt mixtures and binders with waste plastics and electronic wastes within the context of laboratory produced asphalt binder and mixtures specimens using Superpave performance tests. Conclusions from this study include the following: Modified E-Waste Binders become more viscous as e-waste per cent increase in asphalt binders, small amounts of Acrylonitrile butadiene styrene (ABS) within the asphalt binder meet Superpave thermal cracking specifications, and dynamic Shear Rheometer (DSR) results indicate comparable to improved rutting performance when implementing modified e-waste binders. Future research work will develop modified e-waste asphalt binders and mixtures based upon Superpave characterization tests to determine e-waste particle size effects and improvement in preventing asphalt pavement damage and distress.

 

Methods for Evaluating Fly Ash for Use in Highway Concrete

Sponsor: National Academy of Sciences

PI: Lawrence L. Sutter

Photo Quora.com

Initially researched as NCHRP 18-13:  Specifications and Protocols for Acceptance Tests of Fly Ash Used in Highway Concrete

Fly ash—a byproduct of coal combustion—is widely used as a cementitious and pozzolanic ingredient in hydraulic cement concrete. The use of coal fly ash (CFA) in concrete is increasing because it improves some properties of concrete and often results in a lower cost of concrete. However, the chemical and physical compositions of CFA influence constructability, performance, and durability and may contribute to problems, such as cracking and alkali-silica reactivity (ASR) in concrete pavements, bridge decks, and other highway structures. Regulatory requirements have also contributed to changes in CFA properties that may adversely affect concrete performance. In addition, current specifications and test methods do not adequately characterize CFA properties, address the effects of CFA characteristics on fresh and hardened concrete properties, or consider the alkali content of the cement. For example, carbon content of CFA is not usually determined directly but is often assumed to be approximately equal to the loss on ignition (LOI). Such inadequate characterization may lead to unwarranted restrictions on the use of suitable materials. Although a great deal of research has been performed on the effects of CFA characteristics on concrete properties, the research has not dealt with the applicability of current specifications to the fly ashes that currently are produced. In addition, existing test methods for sampling and testing CFA used in concrete do not adequately address the characterization of CFA or the performance aspects of highway concrete. Further research is needed to develop recommendations for improving CFA specifications and test protocols and thus help highway agencies better evaluate and use CFA that will provide acceptable structural performance and durability. NCHRP Project 18-13 was initiated to address this need.

Read the full report:
Methods for Evaluating Fly Ash for Use in Highway Concrete

Lawrence Sutter
Lawrence Sutter

Field Study of Air Content Stability in the Slipform Paving Process

Sponsor: Applied Pavement Technology, Inc.

PI: Lawrence Sutter

This study evaluated the impacts of construction on the air content and air void system structure of Portland cement concrete pavements. The primary intent was to quantify the air content of fresh concrete before and after it had gone through the slipform paver. The air void system parameters of hardened concrete were then assessed with cast cylinders and extracted core specimens. The results of the air content testing on fresh concrete and the concrete cylinder specimens cast in the field suggested that some loss of air (approximately 1%) occurred as the concrete passed through the paver. Laboratory testing performed on cores extracted from the pavement did not provide conclusive evidence that entrained air was lost during the slipform paving process. In fact, many extracted cores had measured air content values that were much higher than those measured in the fresh concrete and even higher than the specification requirement. If excessive, such values could result in increased permeability and low-strength-related issues. The results suggested that the air content testing on fresh concrete did not capture the true air content of the concrete as it was placed with a slipform paver. The fresh concrete air content in general was lower than was the air content measured in the cores.

Read the full report:
Field Study of Air Content of Air Content Stability in the Slipform Paving Process

Lawrence Sutter
Lawrence Sutter

Laboratory Study for Comparison of Class C Versus Class F Fly Ash for Concrete Pavement

SPONSOR:  WISCONSIN DEPARTMENT OF TRANSPORTATION (WISDOT)

PI: Lawrence Sutter

Photo by Alibaba.com

The two objectives of this research were to a) evaluate Class F and Class C fly ash sources for use in paving concrete and b) determine acceptable proportions of each ash type to use in paving mixtures. A combined study was performed involving characterization with respect to AEA adsorption using the foam index test, direct measurement of adsorption, and the iodine number test and a partial factorial experiment was conducted to evaluate concrete mixtures prepared using different fly ash, cement, and aggregate sources. The adsorption testing highlighted known inconsistencies of loss on ignition measurements. Freeze-thaw testing in 4% CaCl2 solutions indicated no statistical difference in performance with or without fly ash but fly ash type was a significant factor in mixtures that failed freeze-thaw testing. Compressive and flexural strength followed the classical behavior expected of fly ash mixtures. Maturity showed the largest impact of fly ash addition. Overall the Class F and Class C ash sources performed well and using either at substitution levels up to 30% is recommended. Additional scrutiny of some Class F sources, with respect to freeze-thaw performance, is warranted. Use at higher levels should be done only after performance testing of the specific combination of materials to be used at the job-mix proportions.

A copy of this report can be found on the Wisconsin Department of Transportation website.

Lawrence Sutter
Lawrence Sutter