Download or read book Evaluate Recycled Concrete as Hot Mix Asphalt Aggregate written by Haifang Wen and published by . This book was released on 2011 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Recycled Asphaltic Concrete written by Charles S. Hughes and published by . This book was released on 1977 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes a project in which approximately 6,200 tons (5,630 Mg) of asphaltic concrete were recycled through a conventional asphalt batch plant. During the construction of the project, a buildup of asphalt-coated fines occurred in the dryer and the dust collector. The buildup is thought to have been associated with the fineness and/or the high asphalt content of the recycled mix. To solve the problem, a change was made in the recycling process. The project was completed using a heat transfer method with mix proportions as high as 50% recycled material added to 50% virgin aggregate.
Download or read book Evaluation of Various Treatment Methods for Enhancing the Properties of Recycled Concrete Aggregate for Hot Mix Asphalt written by Hanaa Al-Bayati and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The application of treated CRCA with heat treatment and short mechanical treatment leads to an increase in the rutting resistance, a decrease in the total rut depth, a slight increase in the stiffness modulus, and an increase in the rutting factor of asphalt mixtures depending on the type of CRCA. The application of treated CRCA with the pre-soaking method and short mechanical treatment results in an increase in the stiffness and rutting factor of mixtures, depending on the type of CRCA. The findings demonstrated that the mixtures that included untreated CRCA have much higher ITS values than the control mix, registering a significant increase of 68%, 70%, 85.6% and 86.7%, for the mixtures that included 30% untreated CRCA#1 and CRCA#2 in both unconditioned and conditioned samples, respectively. This is followed by the ITS values of the mixtures that included 60% untreated CRCA#1 and CRCA#2 for both unconditioned and conditioned samples with an increase of 41.4%, 49.0%, 71.5%, and 56.8%, respectively. Additionally, a reasonable improvement in the ITS values in both conditioned and unconditioned samples were recorded for the mixtures that included 30% treated CRCA with different treatment techniques compared to the mixture that included 30% untreated CRCA. Furthermore, all tensile strength ratio (TSR) values for mixtures that included untreated CRCA with different types and percentages are higher than the minimum required value of MTO specifications. This indicates a successful application for CRCA in these mixtures. The use of the combination technique of pre-soaking method with weak acid followed by a short mechanical treatment method was a highly successful method for enhancing moisture resistance of asphalt mixtures as compared to other combination methods. From TSRST test, the findings indicated that the fracture temperature is reduced due to the CRCA addition compared to the control mix. However, there is no significant influence for the RCA type on the thermal cracks at low temperatures. Additionally, the fracture stress of the mixtures that included different untreated CRCA types with various proportions is generally higher than the fracture stress of the control mix Furthermore, the application of the combination of various treatments leads to a significant reduction in the fracture temperature, indicating a successful application of treated CRCA in HMA mixtures in cold regions. However, the combination of heat at 300 °C and short mechanical treatment has a considerable impact on the fracture temperature of asphalt mixtures as compared to other combination techniques. The results of ANOVA statistical analysis showed that the type of CRCA had a significant effect on the stiffness and rutting, ITS, and the fracture temperature of asphalt mixtures. Additionally, the type of treatment method had a considerable effect on the stiffness, rutting, and fracture temperature of HMA mixtures. In contrast, both the type of treatment method and the type of CRCA have an insignificant effect on the fracture stress of asphalt mixtures. The results of cost analysis revealed that both heat and pre-soaking treatment is quite reasonable, referring to many economic benefits and indicating that these treatment methods could be applicable. In conclusion, the results of this study indicate that the application of different CRCA types in various forms: treated and untreated is very successful and can contribute greatly towards more RCA applications in the asphalt pavements.
Download or read book Evaluation of Recycled Hot Mix Asphalt Concrete on Route 220 written by Charles S. Hughes and published by . This book was released on 1985 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes the performance of an approximately 8-mi section of roadway on which the rod two layers of asphalt concrete were milled, recycled through a conventional asphalt batch plant, and relaid. The recycled mix consisted of about 40% recycle material., 60% virgin aggregate, and 3.0% AC-5 asphalt cement. The project was accomplished with little difficulty and proved once again that recycling is an economical, feasible process. Over the 3 years the mix has been in service it has given very good performance and has provided impetus for the adoption in Virginia of a specification that allows a contractor to use as much as 25% recycle material in his hot mix production at his option.
Download or read book Evaluation of Properties of Recycled Asphalt Concrete Hot Mix written by Elton R. Brown and published by . This book was released on 1983 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recycling of aged asphalt concrete pavements has been demonstrated to be cost-effective and to reduce the demand for natural resources such as aggregate and asphalt. Because of the advantages derived when using recycled materials, the capability to predict long-term performance is needed so that optimum benefits can be obtained. This study was undertaken to evaluate the laboratory performance to recycled asphalt concrete mixtures and to compare these results to those measured for conventional asphalt concrete mixtures. Results of this study indicated a satisfactory comparison between laboratory performance of recycled mixtures and conventional mixtures. Fatigue analysis indicated that conventional mixtures would provide the greatest fatigue resistance in thick asphalt concrete layers at lower temperatures, while the recycled mixtures would provide the greatest fatigue resistance in thin asphalt layers at higher temperatures. Water susceptability was shown to be related more to aggregate type than to mixture type. The data show that recycled mixtures prepared with the recycling agent produced mixtures with the lowest durability and poorest low temperature performance when compared with the recycled mixtures prepared with AC-5 or compared with the conventional mixtures.
Download or read book Improved Mix Design Evaluation and Materials Management Practices for Hot Mix Asphalt with High Reclaimed Asphalt Pavement Content written by Randy Clark West and published by Transportation Research Board. This book was released on 2013 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: TRB's National Cooperative Highway Research Program (NCHRP) Report 752: Improved Mix Design, Evaluation, and Materials Management Practices for Hot Mix Asphalt with High Reclaimed Asphalt Pavement Content describes proposed revisions to the American Association of State Highway and Transportation Officials (AASHTO) R 35, Superpave Volumetric Design for Hot Mix Asphalt, and AASHTO M 323, Superpave Volumetric Mix Design, to accommodate the design of asphalt mixtures with high reclaimed asphalt pavement contents.
Download or read book Evaluation of Properties of Recycled Asphalt Concrete Hot Mix written by Elton R. Brown and published by . This book was released on 1984 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Using Alkali silica Reaction Affected Recycled Concrete Aggregate in Hot Mix Asphalt written by Brian James Geiger and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of using alkali-silica reaction (ASR) affected recycled concrete aggregate (ASR-RCA) in hot mix asphalt (HMA) were investigated in this study. Dilatometer and modified beam tests were performed to determine the possibility of new ASR occurring in reactive aggregates within the HMA or re-expansion of existing gel. The Lottman test and micro-calorimeter were used to determine the moisture susceptibility of HMA made with ASR-RCA. A differential scanning calorimeter (DSC) with thermogravimetric analysis (TGA) was used to evaluate the drying of an artificial gel and x-ray diffraction (XRD) was used to check for the potential presence of gel in the filler fraction of the ASR-RCAs. Micro-deval and freeze-thaw tests were evaluated for their potential to indicate the presence of excess micro-cracks or ASR gel. Expansion testing indicated that both ASR-RCAs were still reactive with 0.5 N NaOH solution saturated with calcium hydroxide (CH) at 60°C. Dilatometer testing of HMA specimens in NaOH CH solution at 60°C indicated a reaction between the asphalt binder and the solution, but little, if any, ASR. The lack of expansion in the modified beam test supports the binder-solution interaction. However, dilatometer testing in deicer solution at the same temperature indicated that some ASR may have occurred along with the primary binder-solution interaction. The volume change characteristics associated with the binder-solution interaction with and without ASR was supported by the change in pH and alkali concentration of the test solution. DSC/TGA testing indicated that the artificial gel dehydrated at approximately 100°C. XRD analysis of the filler indicated that some gel may have accumulated in this fraction. Moisture damage testing indicated good resistance to moisture damage by HMA mixtures made with ASR-RCA especially compared to a virgin siliceous aggregate. Micro-deval and freeze-thaw tests can detect the presence of micro-cracks due to ASR in ASR-RCAs as higher mass loss than the virgin aggregate. The potential distress mechanisms that may occur when using ASR-RCA in an HMA pavement were identified. Results obtained using accelerated laboratory conditions were extrapolated based on anticipated field conditions. Guidelines for the mitigation of potential distresses in HMA made with ASR-RCA are presented.
Download or read book Hot mix Asphalt Mixtures written by and published by . This book was released on 1999 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Cement and Fly Ash Treated Recycled Asphalt Pavement and Aggregates for Base Construction written by Tyson David Rupnow and published by . This book was released on 2011 with total page 2 pages. Available in PDF, EPUB and Kindle. Book excerpt: INTRODUCTION: Many entities currently use recycled asphalt pavement (RAP) and other aggregates as base materials, temporary haul roads, and, in the case of RAP, hot mix asphalt construction. Several states currently allow the use of RAP combined with cement for a stabilized base course under both asphalt and concrete pavements. Currently, there is disagreement on what properties are required and how to test the cement and fly ash treated RAP for both asphalt and concrete pavement structures. This project investigated cement and fly ash treated RAP and other materials to determine their suitability for base course construction. OBJECTIVE: The objective of this research was to determine feasibility of cement and fly ash treated RAP and other aggregates as a structural layer for both portland cement concrete and hot mix asphalt pavement systems.
Download or read book Study of Hot Mix Recycling of Asphalt Pavements written by Frank Meyer and published by . This book was released on 1983 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: Interest in hot mix recycling has recently been stimulated by:rising cost of asphalt cement and fuels; depletion and risingcosts of readily available conventional aggregate resources; theneed to reduce energy consumption; reduction in available fundsfor transportation facilities due to inflation; and, environmental problems due to mining of aggregate materials. Since hot mix recycling can offer advantages in all these areas, the overall objective of this project is to encourage the use ofthis cost and energy efficient strategy in the rehabilitation andmaintenance of pavements in the national road system.
Download or read book Evaluation of Reclaimed Asphalt Pavement and Recycled Concrete Aggregate as a Dense Graded Aggregate Base Course written by Robert Fredwin Baker and published by . This book was released on 1999 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Cement and Fly Ash Treated Recycled Asphalt Pavement and Aggregates for Base Construction written by Tyson David Rupnow and published by . This book was released on 2011 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this study was to determine feasibility of cement and fly ash treated recycled asphalt pavement (RAP) and other aggregates as a structural layer for both portland cement concrete and hot mix asphalt pavement systems. A 610 limestone from Kentucky was used as the reference material. Other materials used in the study include: Mexican 610 limestone, gravel and limestone based RAP, and blended calcium sulfate (BCS). Samples were prepared with three cement and fly ash contents and tested for compression and flexural strength. Length changes specimens were also produced and the resilient modulus was measured.
Download or read book Hot In place Recycling of Asphalt Concrete written by Joe W. Button and published by . This book was released on 1994 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: This synthesis will be of interest to administrators, pavement designers, highway, material, research, and specification engineers, and others interested in economical methods for reconstructing or rehabilitating asphalt concrete pavements. It describes the processes and equipment used for hot in-place recycling of asphalt concrete and provides information on mix designs, performance, and guidelines for its effective use. A significant amount of the information provided is based on the current practices of state highway agencies. As such, numerous case histories are included in the report.
Download or read book Semiconductor Laser Theory written by Prasanta Kumar Basu and published by CRC Press. This book was released on 2015-07-16 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides the reader with a comprehensive background of semiconductor lasers. It covers their structure, materials, operating principles supported by proper theory, and light power output, as well as conversion efficiency and how frequently the devices can be switched on and off. It also discusses the different lasers working at different wavelengths, viz, ultraviolet, visible, infrared and mid and far infrared regions of electromagnetic spectrum along with proper structure, materials and theory.
Download or read book Aggregate Tests for Hot mix Asphalt Mixtures Used in Pavements written by Thomas D. White and published by Transportation Research Board. This book was released on 2006 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduction and research approach -- Findings -- Interpretation, appraisal, and application -- Conclusions and suggested research -- References -- Abbreviations used without definitions in TRB publications.
Download or read book A Manual for Design of Hot Mix Asphalt with Commentary written by and published by Transportation Research Board. This book was released on 2011 with total page 285 pages. Available in PDF, EPUB and Kindle. Book excerpt:
