Robinette C.J.,Granite Construction Inc. |
Breakah T.M.,Iowa State University |
Williams R.C.,Iowa State University |
Bausano J.P.,Sem Materials L.P.
Road Materials and Pavement Design | Year: 2010
The dynamic complex modulus test is quickly coming into the mainstream of practice for research purposes and implementation by owner/agencies. Past research projects have developed estimated limits of accuracy for laboratory mixed/laboratory compacted specimens, however there is little information for field mixed/laboratory compacted specimens. The dynamic complex modulus test was conducted on each of 17 field mixed/laboratory compacted mixtures with various volumetric properties and three replicate specimens to evaluate test variability. Included were factors believed to affect the results and variability of the dynamic modulus test. Statistical analysis was performed to determine the significance of the factors. The results of the analysis showed that three main factors were significant contributors to the variability of the dynamic complex modulus test results (nominal maximum aggregate size, test temperature, and binder grade). Six factors were checked and validated to be the main contributors in the dynamic modulus values (air voids, asphalt content, frequency, temperature, use of recycled asphalt pavement, and binder grade). © 2010 Lavoisier, Paris.
Hand A.,Granite Construction Inc.
Asphalt Paving Technology: Association of Asphalt Paving Technologists-Proceedings of the Technical Sessions | Year: 2013
The objective of the presentation was to answer the question - "As an asphalt contractor what are the company objectives for using sustainable technologies?" For Granite, the sustainability goal optimizes economic (return on investment or ROI), environmental (compliance), and social (citizenship) impacts. Granite's sustainability plan includes: • Operation of energy-efficient asphalt production facilities on a per-unit consumption basis; • Responsible use of sustainable materials technologies without compromising the quality of the end-product; • Increased use of recycled materials in asphalt pavements; and • Increased use of WMA consistent with quality objectives. As an example of the economic component of the sustainability goal (ROI), Dr. Hand noted that Granite invested in modifications to ten mixing plants to reduce losses, improve energy consump tion, reduce energy costs, and account for peak demands. Examples of improvements included insulating drums and hot oil piping and installing variable frequency drives on baghouse fans. The presentation also examined Granite's use of RAP. Dr. Hand noted that RAP was initially separated into three piles depending on the source. A and B piles are formed from known sources (projects) and are expected to have lower binder stiffness and good aggregate qualities - which permits maximized use of RAP with minimized virgin binder grades. C piles include imported RAP and is more typically used in EnviroBase. Dr. Hand also noted that fractionation of RAP was common as the percentage of RAP used exceeds 25%. Fractionating provides reduced variability and allows the use of the finer RAP fraction (<9.5 mm) which has a higher binder content (allowing a greater binder replacement). Dr. Hand also reviewed the sustainable technologies in use today including RAP, RAS, WMA, Crumb Rubber Modified mixes, and Ground Tire Rubber modified asphalt. Dr. Hand focused on WMA as an example and noted how the selection of WMA technology impacted the ROI (cost of equipment and technology), and Compliance/Citizenship (reduced energy use and emissions) while maintaining quality (improvement of workability and attainment of density).
McTavish R.,Granite Construction Inc. |
Stallard R.,Granite Construction Inc.
Journal of Construction Engineering and Management | Year: 2011
The factors that are considered in analyzing technical solutions and the tools used to obtain technical solutions have changed for construction engineers over the past 30 years. This paper discusses these changes and their impacts. It then outlines a process that several heavy civil contracting firms use to generate work plans for their field operations, using the details of the process at Granite Construction as an example. The paper concludes by identifying the key factors in the success of a work plan and providing some thoughts on what construction engineering education should emphasize. © 2011 American Society of Civil Engineers.
Robinette C.,Granite Construction Inc. |
Epps J.,Granite Construction Inc. |
Epps J.,Texas A&M University
Transportation Research Record | Year: 2010
Today, public agencies responsible for roads, streets, and highways are experiencing significant increases in the price of construction operations and asphalt binder availability; they are also experiencing limited available funds and the uncertainty of inflation. Those concerns are coupled with significant pressure to build, maintain, and rehabilitate "green," and agencies must look to alternative construction, rehabilitation, and maintenance methods as well as alternative materials that deliver on both of these seemingly different forces. Life-cycle assessment was used to evaluate roadway construction activities. Life-cycle assessment is similar to life-cycle cost analysis, except that environmental impact is considered over the analysis period. Life-cycle assessment includes energy consumption, emissions generation, and natural resource consumption in addition to price of the activity. All activities evaluated were compared with conventional materials and means of construction. Materials evaluated specific to hot-mix asphalt included reclaimed asphalt pavement, asphalt shingles, and warm-mix asphalt. Aggregate base stabilization and subgrade treatments were evaluated as part of a low- and high-traffic-volume facility. The final evaluation considered rehabilitation and maintenance activities that focused on in-place recycling, such as hot in-place and cold in-place recycling. In most instances, these activities can reduce energy consumption and emissions generation and can conserve natural resources (aggregate and asphalt binder), plus offer the benefit of reducing the price of construction. These materials and technologies show promise in helping agencies meet the rising price of construction while addressing public concern for the environment.