 Using Medical X-Ray Machine to Determine the Service Life of ConcreteNovember 11, 2019 Concrete is a porous material that allows materials to move through it. The number of pores connected in the concrete, also known as the permeability, influences the ability of fluids to penetration the concrete. And this permeability parameter is an important transport mechanism for freeze-thaw damage, corrosion, alkali silica reaction, and sulfate attack. The TRB Innovations Deserving Explora...
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 Primer on Bridge Load TestingNovember 8, 2019 Load testing of bridges to assess bridge performance has been in practice since at least 1891 in Switzerland. In times when engineering models were not as accurate and available as today, a critical step in the construction of a bridge was to load test prior to opening or during the opening ceremony of the bridge. Several bridges, including ones in Serbia, Switzerland, and France, collapsed dur...
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 Nano-Enabled Multifunctional Concrete for Transportation InfrastructureOctober 24, 2019 Concrete is the most widely used synthetic material on earth. In the U.S., more than 75 percent of bridges and more than 60 percent of interstate highways are made of concrete. There is no other bulk material on the horizon that could replace concrete as the backbone for our increasing demands in infrastructures. Despite several decades of studies, concrete bridges, highways and infrastructures...
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 Relationship Between Laboratory Cracking Tests and Field Performance of Asphalt MixturesOctober 7, 2019 Information exchanged during the 97th Annual Meeting of the Transportation Research Board in a session titled "Relationship Between Laboratory Cracking Tests and Field Performance of Asphalt Mixtures" is captured in Transportation Research Circular E-C251: Relationship Between Laboratory Cracking Tests and Field Performance of Asphalt Mixtures . The document explores a significant amount of wor...
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 Evaluating the Effects of Recycling Agents on Asphalt Mixtures with High RAS and RAP BinderSeptember 30, 2019 More than 90 percent of highways and roads in the United States are built using hot-mix asphalt (HMA) or warm-mix asphalt mixtures, and these mixtures now recycle more than 99 percent of some 76.2 million tons of reclaimed asphalt pavement (RAP) and about 1 million tons of recycled asphalt shingles (RAS). According to the National Asphalt Pavement Association, cost savings in 2017 totaled appro...
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 Simulation Options for Airport PlanningSeptember 19, 2019 Global business and tourism depend heavily on the efficient operation of airports and movement of passengers, baggage, and cargo across many areas. With increasing demand and connectivity requirements for airports comes the need for more sophisticated simulation and modeling tools to validate design assumptions. Furthermore, airport design and planning decisions have significant impacts on poli...
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 Guidelines for Collecting, Applying, and Maintaining Pavement Condition Data at AirportsSeptember 12, 2019 “Pavement condition data” are essential inputs to the process of managing airport pavements and ensuring safe operations. The technology available today to collect pavement condition data is considerably different from that available even 20 years ago, and new technologies are being developed and introduced into practice at a rapid pace. ACRP Research Report 203: Guidelines for Collecting, Appl...
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 Measuring, Characterizing, and Reporting Pavement Roughness of Low-Speed and Urban RoadsSeptember 5, 2019 Pavement smoothness (or roughness) is used by state highway agencies for monitoring network condition and other purposes such as assessing construction quality and optimizing investments in preservation, rehabilitation, and reconstruction. States are also required to report the International Roughness Index (IRI) as an element of the federal Highway Performance Monitoring System (HPMS). Because...
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 Practices to Mitigate Alkali-Silica Reaction (ASR) Affected Pavements at AirportsAugust 22, 2019 Some concrete pavements commonly used at airports are susceptible to the destructive effects of alkali-silica reaction ( ASR). The presence of ASR on concrete pavements can have a devastating effect on pavement performance, not only in terms of reduced functionality, but also in terms of shortened service lives. The focus of ACRP Synthesis 96: Practices to Mitigate Alka...
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 Transportation Research Circular E-C248: 12th International Conference on Low-Volume RoadsAugust 6, 2019 TRB’s Technical Activities Division has released Transportation Research Circular E-C248: 12th International Conference on Low-Volume Roads, highlighting topics including road surfaces, geotechnology, cold regions and climate change, pavement management, planning and economics, unpaved roads management, geosynthetics in low-volume roads, drainage and stream crossings, climate change resiliency,...
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 Automated Pavement Condition SurveysJuly 23, 2019 TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 531 documents agency practices, challenges, and successes in conducting automated pavement condition surveys. The report also includes three case examples that provide additional information on agency practices for conducting automated pavement surveys. Pavement condition data is a critical component for pavement management s...
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 Impact of Asphalt Thickness on Pavement QualityJuly 2, 2019 TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 537: Impact of Asphalt Thickness on Pavement Quality documents transportation agency policy for lift thickness and minimum compaction requirements on resultant asphalt pavement quality. To achieve expected pavement performance, it is important that asphalt concrete (AC) have adequate density. A critical factor in achieving th...
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