Download or read book Hydraulic Properties of Recycled Pavement Aggregates and Effect of Soil Suction on Resilient Modulus for Pavement Design written by and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The successful incorporation of recycled aggregates in pavement design is important for achieving a higher level of sustainability in our transportation network. However, recycled aggregates are non-soil materials and have different unsaturated hydraulic and resilient modulus characteristics. This study investigated the unsaturated hydraulic properties and impact of soil suction on resilient modulus for compacted recycled aggregates used as unbound base course, including recycled asphalt pavement (RAP), recycled concrete aggregate (RCA), and recycled pavement material (RPM). Hydraulic properties and relationships including the soil-water characteristic curve (SWCC) and saturated and unsaturated hydraulic conductivity were characterized using a hanging column test coupled with a large-scale testing cell. Regression of the hydraulic parameters from SWCC and unsaturated hydraulic conductivity; data for each type of recycled materials was completed. The effect of water repellency on hydraulic properties was evaluated. Development of testing equipment and procedures that incorporate the effect of soil suction during resilient modulus measurement is presented. A mathematical model to predict resilient modulus based on bulk stress, octahedral shear stress, and soil suction is proposed. In addition, empirical relationships for predicting summary resilient modulus (SRM) via soil suction and SRM at optimum compaction for recycled aggregates are presented. Measured SRM and SWCCs for different types of recycled aggregate were used to evaluate flexible pavement performance according to the approach outlined in the Mechanistic-Empirical Pavement Design Guide (M-EPDG). The impact of environmental effects (including freeze-thaw cycles and changes in temperature) on the resilient modulus of recycled aggregates and subsequent pavement performance are evaluated and presented in this dissertation.

Download or read book Use of Recycled Aggregate Materials Characteristics in Pavement Design Analyses written by Ida Gheibi and published by . This book was released on 2020 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: Use of recycled materials promotes sustainability in roadway construction by reducing consumption of energy and emission of greenhouse gases associated with mining and the production of natural aggregates. Recycled asphalt pavements (RAP) and recycled concrete aggregates (RCA) have comparable characteristics to natural aggregates that are currently used in roadway base course applications. This study has developed a database for RAP and RCA materials' characteristics including resilient modulus (Mr), California bearing ratio (CBR), gradations along with construction specifications. RAP and RCA relationships with different engineering and index properties were investigated and some trends were proposed such as higher RAP content reveals higher summary of resilient modulus (SMr), higher RCA content causes higher optimum moisture content (OMC) and lower maximum dry unit (MDU).In addition, pavement mechanistic-empirical (ME) analyses have been conducted with the material inputs collected for the database to determine whether different values of different characteristics of RCA and RAP can be used in flexible or rigid pavement designs. Results showed that Mr parameter had the highest impact on pavement distress predictions among gradations and hydraulic conductivity.

Download or read book Hydraulic and Mechanical Properties of Recycled Materials written by Satish C. Gupta and published by . This book was released on 2009 with total page 219 pages. Available in PDF, EPUB and Kindle. Book excerpt: Construction and maintenance of roads requires large volume of aggregates for use as base and subbase materials. Because of the cost of virgin aggregates, federal and state agencies are encouraging the recycling of waste materials including materials in old pavements. This study assessed the suitability of four recycled materials relative to virgin aggregates for use as base and subbase materials. The four recycled materials were the reclaimed asphalt pavement (RAP), fly ash (FA), reclaimed concrete material (RCM), and foundry sand (FS). Assessment of these materials was done in terms of their hydraulic, mechanical, and leaching properties when mixed in with various proportions of virgin aggregates. Except for slightly higher fine content in some RAP-aggregate mixtures, particle size distribution of all mixtures was within the Mn/DOT specification band for Class 5 materials. Water retention (pore size distribution), hydraulic conductivity, resilient modulus, and shear strength measurements were generally similar to that of 100% aggregates. Exception was the mixtures of FS. Heavy metal concentrations in the leachate were also generally less than the EPA drinking water standards. We concluded that FA, RAP, and RCM mixtures will be good substitutes of virgin aggregates as base and subbase materials.

Download or read book Evaluation of the Effects of Climatic Conditions on Modulus of Base Materials with Recycled Asphalt Pavement written by Haifang Wen and published by . This book was released on 2011 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of recycled materials for construction is beneficial to both the environment and the economy. Recycled asphalt pavement (RAP) is one of the most commonly used recycled materials. Different state departments of transportation allow the use of RAP in base materials at different percentages. Characterization of the resilient modulus of base materials with RAP is important for proper pavement design. In addition, the models used in the Mechanistic-Empirical Pavement Design Guide (MEPDG) for traditional materials need to be verified for base materials with RAP, due to the unique properties of asphalt in RAP. This study evaluated the effects of moisture and temperature on the resilient modulus of base materials with different percentages of RAP. The models for the effects of moisture content on the resilient modulus of unbound materials were evaluated using crushed aggregates with RAP. In addition, models were proposed to account for the effects of temperature on the resilient modulus of base materials with RAP. The effects of the percentage of RAP on frozen moduli were also investigated.

Download or read book Resilient Modulus of Recycled Aggregates as Road Pavement Materials written by Pralendra Singh and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The sources of natural or virgin coarse aggregates are diminishing in alarming rate and its production is quite expensive, uses a lot of energy, and is not environmental friendly. Hence, utilizing the recycled aggregates like reclaimed or recycled concrete aggregate (RCA) and recycled asphalt pavement (RAP) on road pavement will not only preserve the natural aggregates but also reduce the negative environmental impact. It also helps to conserve the waste landfill sites. The major downside for the use of the recycled aggregate is the quality control during its production. This research characterizes RCA samples obtained from a demolished old foundation and RAP samples from old parking lot and determines their suitability as road pavement materials. Virgin aggregates, recycled aggregates, and several blended mixtures with 20 to 80% replacement of natural coarse aggregate or virgin aggregate (NCA or VA) by weight with RCA and RAP were prepared and tested for resilient modulus (M r) and California Bearing Ratio (CBR) test. The durability of the virgin aggregate and recycled aggregate were also determined by micro-deval test. The resilient modulus value of 100% RCA and 100% VA was found to be very similar or higher but for 100% RAP the resilient modulus is higher than that of the 100%VA. The Resilient modulus of the RAP blended mixtures increases with the increase in the content of RAP percentage and for the RCA it was not consistent. The CBR values for the blended mixtures decreases with the increase in the percentage of the recycled aggregates. The micro-deval degradation test result for RCA was more than of VA due to presence adhere materials in RCA.

Download or read book The Relationship Between Resilient Modulus and Soil Suction of Fine Grained Soil in Pavement Design written by Augustine Wittonde Phillip and published by . This book was released on 1996 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Performance of Cement Treated Recycled Aggregates Under Wetting drying Cycles in Pavement Base written by Saif Bin Salah and published by . This book was released on 2017 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: Resilient Modulus (MR) is one of the most important stiffness parameter to determine the thickness of a pavement layer (AASHTO 2003 pavement design guideline). Recent studies conducted by researchers on the variability of MR with wetting-drying (WD) and freeze-thaw (FT) cycles show that long-term durability is an important criterion to be considered in designing pavement base with recycled materials. At present, the design procedure does not consider the effect of deterioration of pavement layers due to seasonal variations and limited studies have been conducted to evaluate the effect of environmental deterioration on the reclaimed asphalt pavement (RAP) and recycled crushed concrete aggregate (RCCA) mixtures stabilized with cement. The objective of this study is to evaluate the long-term durability of RCCA and RAP mix materials under repeated wetting-drying cycles. Three different combinations of RCCA and RAP materials containing 0%, 30% and 50% RAP content were used in this study. Each of these combinations were then stabilized with 4% and 6% cement content. After curing for 7 days the samples prepared from these material combinations were subjected to 4, 8, 16 and 30 wetting-drying (W-D) cycles. For the purpose of comparison, a different set of samples of the same combinations were prepared, cured for 7 days, and then further cured for 15, 25, 40 and 70 days. Resilient modulus tests were then conducted on all the samples at the end of these specified W-D cycles and curing periods. Environmental tests were also conducted to assess the effect of WD cycles on the washed-out water quality. These tests included total suspended solids (TSS), total dissolved solids (TDS), turbidity, chemical oxygen demand (COD) and pH. MR test results indicated that addition of 50% RAP into the mix reduced the resilient modulus (MR) by about 39%. Increasing the cement content from 4% to 6% increased the MR values by about 20-35% for all material combinations. Higher cement content also resulted in higher durability of the materials containing 30% and 50% of RAP. All the six material combinations used in this study showed adequate strength after 7-days of curing. But the mix containing 30% RAP + 70% RCCA 4% cement (30R_4C) and 50% RAP + 50% RCCA 4% cement (50R_4C) failed to meet the minimum layer coefficient value of 0.13 (AASHTO 2003) for pavement base layer after 8-16 wetting-drying cycles. Results obtained from the environmental tests after 30 WD cycles were found to be within the permissible values provided by EPA guidelines.

Download or read book Resilient Modulus Development of Aggregate Base and Subbase Containing Recycled Bituminous and Concrete for 2002 Design Guide and Mn Pave Pavement Design written by Thomas M. Westover and published by . This book was released on 2007 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary objective of this study was to quantify stiffness (resilient modulus) of aggregate base containing recycled asphalt and concrete pavements. After a survey of other state's specifications and implementation guidelines, Minnesota recycling projects were selected based on the availability of laboratory resilient modulus (MR) tests and field measurements from FWD. The projects were County State Aid Highway 3, Trunk Highway 23 and Trunk Highway 200. Based on the results of a parametric study, it was found that traditional peak-based analysis of FWD data can lead to significant errors in elastostatic backcalculation. A procedure for extracting the static response of the pavement was formulated and implemented in a software package called GopherCalc. Laboratory resilient modulus measurements were compared with moduli backcalculated from the FWD data. The FWD data was analyzed using conventional (peak-based) and modified (FRF-based) elastostatic backcalculation (Evercalc) as well as a simplified mechanistic empirical model called Yonapave. Laboratory values from sequences in the MR protocol that produced a similar state-of-stress were used. Additionally, a seasonal analysis of FWD test data revealed a significant increase in stiffness when the pavement is in the frozen state.

Download or read book Recycled Materials in Geotechnical and Pavement Applications written by Amin Chegenizadeh and published by Springer Nature. This book was released on 2022-02-28 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book considers the application of recycled materials both in pavement and geotechnical engineering. Currently, Australia has faced the fundamental concern of recycling waste plastic. On 1 January 2018, China enforced a prohibition on the importation of waste plastic. China's ban is followed by other countries like India, Indonesia, and Malaysia. The ban caused many corporations to abandon waste collection agreements, and the stockpiling of waste, as there is nowhere to safely deposit this waste. This issue seems, to a great extent, to have placed Australia's recycling industry in a crisis. As a result, local councils will have to find strategic ways of recycling accumulated waste that will become a more significant issue in the coming years. In Australia, apart from economic growth, the road pavement has weakened rapidly as the current pavement unable to withstand this urgent traffic load demand. The adding of polymers to the mixtures improves the stiffness, rutting resistance, and fatigue cracking [1]. However, the application of virgin polymer is costly. Thus, using waste polymer such as waste plastic polymer is an inexpensive substitute. The potential for recycled plastic to improve the performance properties of asphalt mixtures has been demonstrated in many countries the UK, Canada, The Netherlands, and India [2]. Similarly, another application of recycled materials can be in geotechnical infrastructure. This book considers the application of recycled materials both in pavement and geotechnical engineering. References [1] Airey, G.D., Singleton, T.M., & Collop, A.C.(2002). Properties of polymer modified bitumen after rubber- bitumen interaction. Journal of Materials in Civil Engineering .14(4), 344- 354. [2] K. O'Farrell. Australian Plastics Recycling Survey- National Report. Australian Government, Department of Environment and Energy, Australia. Project reference,2018 A21502.

Download or read book Determining Pavement Design Criteria for Recycled Aggregate Base and Large Stone Subbase written by Bora Cetin and published by . This book was released on 2021 with total page 377 pages. Available in PDF, EPUB and Kindle. Book excerpt: This project was performed to evaluate the performance of recycled aggregates and large stones used in the aggregate base/subbase layers of pavement systems and provide recommendations regarding pavement design and material selection. As part of this project, eleven test cells were built at MnROAD to evaluate the impact of recycled aggregates and large stones on the long-term pavement performance via a series of laboratory [permeability, soil-water characteristic curve (SWCC), stereophotography (image analysis), gyratory compaction, and resilient modulus (MR) tests] and field tests [intelligent compaction (IC), falling weight deflectometer tests (FWD), rutting measurements, international roughness index (IRI) measurements, light weight deflectometer (LWD) tests, and dynamic cone penetrometer (DCP) tests]. In addition, a pavement mechanistic-empirical (ME) design approach was used to provide recommendations for designs of pavement systems containing recycled aggregate base (RAB) and large stone subbase (LSSB) layers. Overall, this project found that finer recycled concrete aggregate (RCA) material would be preferable to coarser RCA material and a blend of RCA and recycled asphalt pavement (RAP) materials would be preferable to natural aggregate for aggregate base layers. RCA materials provided better performance than the blend of RCA and RAP materials, indicating that RCA materials would be preferable to the blend. For LSSB layers, this project found that geosynthetics would be required to successfully construct thinner LSSB layers. Overall, thicker LSSB layers provided better structural support than thinner LSSB layers both in the short term and the long term.

Download or read book Reliability Associated with the Estimation of Soil Resilient Modulus at Different Hierarchical Levels of Pavement Design written by Daniel Rosenbalm and published by . This book was released on 2011 with total page 687 pages. Available in PDF, EPUB and Kindle. Book excerpt: Deterministic solutions are available to estimate the resilient modulus of unbound materials, which are difficult to interpret because they do not incorporate the variability associated with the inherent soil heterogeneity and that associated with environmental conditions. This thesis presents the stochastic evaluation of the Enhanced Integrated Climatic Model (EICM), which is a model used in the Mechanistic-Empirical Pavement Design Guide to estimate the soil long-term equilibrium resilient modulus. The stochastic evaluation is accomplished by taking the deterministic equations in the EICM and applying stochastic procedures to obtain a mean and variance associated with the final design parameter, the resilient modulus at equilibrium condition. In addition to the stochastic evaluation, different statistical analyses were applied to determine that the uses of hierarchical levels are valid in the unbound pavement material design and the climatic region has an impact on the final design resilient moduli at equilibrium. After determining that the climatic regions and the hierarchical levels are valid, reliability was applied to the resilient moduli at equilibrium. Finally, the American Association of State Highway and Transportation Officials (AASHTO) design concept based on the Structural Number (SN) was applied in order to illustrate the true implications the hierarchical levels of design and the variability associated with environmental effects and soil properties have in the design of pavement structures. The stochastic solutions developed as part of this thesis work together with the SN design concept were applied to five soils with different resilient moduli at optimum compaction condition in order to evaluate the variability associated with the resilient moduli at equilibrium condition. These soils were evaluated in five different climatic regions ranging from arid to extremely wet conditions. The analysis showed that by using the most accurate input parameters obtained from laboratory testing (hierarchical Level 1) instead of Level 3 analysis could potentially save the State Department of Transportation up to 10.12 inches of asphalt in arid and semi-arid regions.

Download or read book Sustainable Alternative Materials in Unbound Granular Layers of Pavement Structures written by Adam C. Schneider and published by . This book was released on 2017 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: In Part 1 of this thesis, reclaimed cement concrete (commonly referred to as recycled concrete aggregate or RCA) and reclaimed asphalt pavement (RAP) are investigated as potential alternative construction materials for Granular B Type II subbase fill. Ontario Provincial Standard Specification (OPSS) 1010 currently allows the common use of processed reclaimed construction materials in a variety of road base, subbase and asphaltic concrete layers, with the notable exception of Granular B Type II, which at present may only include 100% crushed bedrock, talus, iron blast furnace slag or nickel slag. As more restrictions are placed on zoning and approvals for new natural aggregate extraction sites in Ontario, there is a need to better understand the performance of materials such as RCA and RAP as economically beneficial potential aggregate sources for granular base and subbase fill layers. An experimental program was created to assess and analyze the performance characteristics of a series of different subbase test mixtures incorporating RCA and/or RAP, either pure or blended with crushed bedrock, and the impact of the inclusion of these materials when compared to a conventional 100% crushed bedrock test mix meeting OPSS 1010 requirements for Granular B Type II. The performance characteristics to be assessed were field compactibility, gradations before and after field compaction, physical properties, standard and modified Proctor tests, California Bearing Ratio (CBR), permeability, resilient moduli and lightweight deflectometer (LWD) resilient moduli. Field testing programs conducted at Quarry 1 in Ottawa, Ontario and Quarry 2 in Burlington, Ontario indicate that the subbase test mixtures meeting OPSS Granular B Type II gradation requirements and incorporating different proportions of crushed rock, RCA and/or RAP exhibit similar field rolling compactibility relative to 100% crushed rock. Grain size analysis testing showed some aggregate breakdown in multiple test mixes, with only minimal increases in material passing the 75 μm sieve, which is crucial to preserving permeability and drainage characteristics. Tests using a lightweight deflectometer (LWD) were subject to substantial variability but indicated that mixes using elevated levels of RCA (50% and 100%) can potentially have lower in-situ moduli compared to the other blends tested. Laboratory tests indicate that high replacement levels of RCA can be used in subbase materials as a substitute for 100% crushed rock while maintaining good water permeability characteristics and similar or higher resilient moduli in blends incorporating RCA and/or RAP. CBR testing results were similar across all test blends incorporating crushed rock and RCA, but also indicated that the inclusion of 30% RAP can potentially reduce the bearing capacity of the granular material by approximately 30-40% in comparison to all other blends which do not contain RAP. Based on the overall results of this study, RCA and RAP appear to be capable of successfully substituting for natural aggregates in Granular B Type II in a range of compositional proportions. It is recommended that test sections should be completed on highway contracts with subbase mixture blends incorporating RCA and/or RAP in order to verify their performance in pavement structures in the field. In Part 2 of this thesis, foam glass lightweight aggregates (LWA) are investigated as a potential pavement engineering design alternative in order to mitigate roadway loading impacts upon underlying subgrade soils while promoting the sustainable and economical use of recycled waste glass. Foamyna Canada Inc. supplied the Centre for Pavement and Transportation Technology (CPATT) with two foam glass lightweight aggregate materials, designated in this thesis as LWA-A and LWA-B. Physical properties testing was carried out by CPATT, including grain size analysis, crushed particle content, flat and elongated particle content, Micro-Deval abrasion resistance, cyclic freezing-and-thawing resistance and resilient modulus testing procedures. These procedures were conducted in order to evaluate the LWA materials against locally applicable standards, namely Ontario Provincial Standard Specification document OPSS 1010 as currently used by the Ministry of Transportation of Ontario (MTO). The laboratory testing detailed in Part 2 indicates that both LWA-A and LWA-B have a very consistent and repeatable gradation with a high percentage of coarse aggregates. Both foam glass materials have very high crushed particle contents and very low flat and elongated particle contents. Micro-Deval abrasion resistance, freeze-and-thaw resistance and resilient moduli were also excellent for both materials, while relative density testing indicated LWA material specific gravity values which were substantially lower than that of water. However, it was found that the gradations of these two tested materials do not satisfy the existing requirements of OPSS 1010, which were developed for natural aggregates and, as currently constituted, may not be appropriately adapted to artificial lightweight aggregates. The coarse nature of the LWA materials would be highly beneficial to ensure the stability of the granular layers and prevent upward capillary water movement into other layers of the pavement structure. Pavement design calculations were carried out using the AASHTO 1993 empirical design procedure and found that utilizing foam glass LWA as a lightweight subgrade replacement fill material can result in substantially leaner pavement structures as compared to the use of conventional expanded polystyrene (EPS) geofoam blocks as an artificial subgrade. A life-cycle cost analysis (LCCA) procedure carried out on these pavement designs showed that the use of foam glass LWA as a lightweight fill material underlying pavement can result in overall cost savings of over 30 percent relative to pavement structures which are underlain by EPS geofoam. Overall, the two tested LWA materials showed excellent physical and mechanical characteristics, and would be suitable for use in pavement structures as innovative lightweight and environmentally friendly alternatives to natural aggregate materials.

Download or read book Material Properties for Implementation of Mechanistic empirical M E Pavement Design Procedures written by and published by . This book was released on 2004 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Model for the Prediction of Subgrade Soil Resilient Modulus for Flexible pavement Design written by Beresford O. A. Davies and published by . This book was released on 2004 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: Subgrade soil plays a very important role in the construction of roadways. Before the use of asphalt in the construction of roadway, roads were being constructed based on experience. The introduction of paving asphalt in road construction has led to the development of engineering procedures and designs for the methods of construction. The resilient modulus of the underlying material supporting the pavement is now considered as a key material property in the AASHTO mechanistic-empirical design procedure. Attempts have been made by researchers to predict the Subgrade resilient modulus from laboratory/field experimental methods based on the soil properties. This research seeks to develop a model for predicting the subgrade resilient modulus due to environmental conditions by considering the seasonal variation of temperature and moisture content which affects the soil. The limitation of this research model is that it cannot be used universally since environmental conditions vary from place to place, however, it can be modified to suit other local environmental conditions. The detrimental effect of low resilient modulus of subgrade soil is observed in the damaged analysis.

Download or read book Soil and Material Inputs for Mechanistic empirical Pavement Design 2007 written by American Society of Civil Engineers and published by . This book was released on 2007 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book New Trends in Recycled Aggregate Concrete written by Jorge de Brito and published by MDPI. This book was released on 2019-07-15 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is the result of a Special Issue published in Applied Sciences, entitled “New Trends in Recycled Aggregate Concrete". It identifies emerging research areas within the field of recycled aggregate concrete and contributes to the increased use of this eco-efficient material. Its contents are organised in the following sections: Upscaling the use of recycled aggregate concrete in structural design; Large scale applications of recycled aggregate concrete; Long-term behaviour of recycled aggregate concrete; Performance of recycled aggregate concrete in very aggressive environments; Reliability of recycled aggregate concrete structures; Life cycle assessment of recycled aggregate concrete; New applications of recycled aggregate concrete.

Download or read book The Effects of Mix Design on the Design of the Pavement Structure when Utilizing Recycled Portland Cement Concrete as Aggregate written by James Stanley Fergus and published by . This book was released on 1980 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt: