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Large Scale Model Experiments of Recycled Base Course Materials Stabilized with Cement and Cement Kiln Dust
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Item Code: SN3109
Date of Publication: 2009
Price: $0.00
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The objectives of this study were to determine the resilient modulus of two recycled roadway materials: recycled pavement material (RPM) and road surface gravel (RSG) with and without cement and cement kiln dust (CKD) stabilization. The resilient modulus was determined by conducting Large Scale Model Experiments (LSME) designed to replicate field conditions, and compared with the resilient modulus determined from the laboratory test method described by NCHRP 1-28A. Results of wet-dry and freeze-thaw durability tests were used to select a portland cement content of 4% by weight and a CKD content of 10% by weight to chemically stabilize RPM and RSG. The stiffness at curing times of 7 and 28 days was evaluated, and the summary resilient modulus (SMR) corresponding to a bulk stress of 208 kPa was used to calculate AASHTO base layer coefficients for use in pavement layer thickness design. A conventional base course material specified as a Class 5 material gradation employed in Minnesota, and similar to AASHTO grading C, was used as a reference material.
This thesis was developed as part of the educational requirements of the University of Wisconsin-Madison under a fellowship grant from the PCA Education Foundation.
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Sedimentation of Pervious Concrete Pavement Systems
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Item Code: SN3104
Date of Publication: 2008
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Pervious concrete pavement systems (PCPS) are a unique and effective means to address important environmental issues and support green, sustainable growth, by capturing stormwater and allowing it to infiltrate into the underlying soil. Sedimentation leading to clogging is a potential problem in serviceability of PCPS. The sedimentation rates of pervious concrete with 20% porosity were examined with three different soil types: sand, clayey silt, and clayey silty sand. Pervious concrete beam and cylinder specimens were exposed to sediments mixed in water to simulate runoff with heavy and typical load of soil sediments. Falling head permeability tests were performed in the specimens before and after exposure. Results show that storage capacity will be minimally affected by sediment. Exfiltration rate, however, can be affected by sediment characteristics in some situations. A simple, economical test for estimating exfiltration rates of the system in these situations was also developed. The results of this study were used to develop design guidelines that complement the hydrological design of PCPS considering the effects of sedimentation of the system at end of service.
The effects of realistic freezing rates on frost resistance of pervious concrete, including the effects of sedimentation were also examined. Pervious concrete disk specimens were subjected to freezing and thawing cycles using a unique and innovative test that considers realistic, slow freezing rates of partially saturated, pervious concrete disk specimens. Results confirmed previously published reports that sand must be included in the mixture to be frost resistant when saturated or normally saturated, regardless of the addition of air entraining admixture (AEA).
This thesis was developed as part of the educational requirements of North Carolina State University under a fellowship grant from the PCA Education Foundation.
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Slurry Stabilization and Reaction Chemistry of Cement-Treated Soils
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Item Code: SN3108
Date of Publication: 2009
Price: $0.00
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This project focused on evaluating important parameters for stabilizing soil with cement slurry and also investigated the chemistry of cement-modified soil at curing times up to 24 hours. Cement slurry usage is increasing due to concerns over dusting, and numerous companies and types of equipment are available to apply the slurry. By investigating the impact of cement slurry age, percent solids, and compaction delay time on the performance of cement-stabilized soils in the lab, researchers discovered that slurry age (up to 2 hours) does not affect performance, and slurry percent solids can impact performance in some cases. However, compaction delay time plays a much more significant role in the strength and modulus characteristics of the end product, and this delay time should be accounted for during the design stage. Investigations of the chemistry of cement-modified soils using scanning electron microscopy, differential scanning calorimetry, and X-ray diffraction suggest that after only 10 minutes of curing both C-S-H and portlandite are present. As curing time increases, the amount of C-S-H decreases and the amount of portlandite increases. After 2 hours cure, coatings are developing on the clay, and after 24 hours these coatings are more extensively developed. Additionally, a shift in the montmorillonite basal spacing and a change in the montmorillonite recrystalization peak suggested the cement produced a structural modification. After 24 hours, a measurable amount of cement clinker existed, meaning unreacted cement is available for further reaction.
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The Influence of Curing Temperature on Cement Stabilization of North Carolina Soils
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Item Code: SN3120
Date of Publication: 2008
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Soil stabilization is the process of increasing the quality of in-situ soil so as to make it
functional as an engineering material. There are numerous ways to stabilize soils, both
mechanically and chemically. One type of chemical stabilization includes adding
Portland cement and water to soil, a process known as cement stabilization. At the end of
this process, which involves various stages of mixing, compacting, and curing, the
resulting material is known as “soil-cement.” Soil-cement has been used for decades as a
material capable of withstanding large compressive stresses. The Portland Cement
Association (PCA) first considered the viability of soil-cement after a scientific study
launched by the South Carolina State Highway Department in 1932 revealed promising
results (M. D. Catton 1959). Since then, soil-cement has been thoroughly investigated
and, in turn, standard methods of determining the various engineering properties of the
material have been established by the American Society for Testing Materials (ASTM).
The PCA has also produced guidelines for dealing with soil-cement in its publication
Soil-Cement Laboratory Handbook (PCA 1992).
This thesis was developed as part of the educational requirements of the University of North Carolina at Charlotte under a fellowship grant from the PCA Education Foundation.
DISCLAIMER
The contents of this report reflect the views of the author(s) and not necessarily the views of the University. The author(s) are responsible for the facts and the accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of either the North Carolina Department of Transportation or the Federal Highway Administration at the time of publication. This report does not constitute a standard, specification, or regulation.
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2005 ACPA Profiler Repeatability Test
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Item Code: SN2877a
Date of Publication: 2005
Price: $0.00
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This report describes testing of profiler repeatability on four sections of textured concrete, including transverse tining, longitudinal tining, diamond grinding, and light turf drag. The profilers included only devices with a large-footprint height sensor. The evaluation of repeatability was based on the level of cross correlation between repeat profile measurements after the application of the filters used in IRI calculation.
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A Comparison of Six Environmental Impacts of Portland Cement Concrete and Asphalt Cement Concrete Pavements
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Item Code: SN2068
Date of Publication: 2001
Price: $0.00
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The “environmentally friendly” aspect of products has become increasingly important for building and highway decision-makers. In this report, the authors summarize a literature survey, investigation, and comparison of six specific topics relating to the environmental impact of portland cement concrete and asphalt cement concrete pavements. These areas include (1) the effects of the pavement color on the microclimate, (2) artificial lighting requirements of the pavements at night, (3) the effect of pavements on vehicle fuel consumption, (4) inclusion of waste and recycled materials in pavements, (5) the potential to recycle pavement at the end of its useful life, and (6)
costs during construction, maintenance, and reconstruction. The authors also highlight particular situations where either pavement type provides an advantage to the environment. This report is also found on DVD021.
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Assessment of Profiler Performance for Construction Quality Control: Phase I
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Item Code: SN2877
Date of Publication: 2005
Price: $0.00
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This report documents a profiler verification experiment that tested the performance of inertial profilers on four pavement sections. The repeatability and reproducibility of lightweight profilers on new concrete with coarse texture was of particular interest. The study included six lightweight inertial profilers, three high-speed inertial profilers, two walking-speed profilers, a rod and level survey, and one profilograph. Tests were performed on four sites: (1) moderately rough asphalt of typical surface texture, (2) new longitudinally tined concrete, (3) moderately rough broom-finished concrete, and (4) new transversely tined concrete. Both new concrete sections were selected to assess the sufficiency of existing lightweight profilers on the market for use in construction quality control.
For additional information, see ACPA publications:
TB006P
RT 4.08
RT 4.09
RT 5.01
This report is also found on DVD021.
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Bond Shear Strength of a Rigid Pavement System with a Roller Compacted Concrete Base
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Item Code: SN2990
Date of Publication: 2006
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Roller Compacted Concrete (RCC) is a zero slump, dry concrete which contains more aggregate and less cement than conventional concrete. When RCC is utilized as a pavement, it requires no formwork, reinforcement, joints or dowels and can be placed
similarly to the techniques used for placing hot mixed asphalt. RCC has shown durability in harsh climates, can reach a compressive strength of over 7000 psi, and is resistant to chemical attacks. These properties of RCC make it a more economical and more durable alternative to conventional asphalt and concrete pavements. The only thing keeping RCC from dominating the transportation construction market is that RCC has a rough surface. RCC’s rough surface does not provide the proper rideability for traffic to exceed
moderate speeds. To enhance the surface of the RCC, asphalt overlays have been applied. The asphalt overlays have been performing well, but they lack the strength and durability of a rigid pavement system.
In order for a two layer rigid pavement system to behave properly, adequate adhesion between the base and the overlay must occur. This research explored the different factors that affect the strength of the interface bond. A guillotine shear tester was used on six inch cylinder samples of rigid pavements with an RCC base to evaluate
the bond strength. Variables included different mixture designs for overlays, the use of
internal curing, changes in aggregate type, different air contents, and different interface
preparations.
Despite exhibiting different properties from conventional concrete, RCC behaves similarly as a base with a concrete overlay. They are both affected in the same manner by the type and strength of the overlay, the air content, aggregate type, and bond interface preparation. This knowledge of how the bond strength is developed will assist in exceeding the minimum bond strength desired and thus validating the use of a rigid
pavement system with an RCC base. This thesis was developed as part of the educational requirements of Cleveland State University under a fellowship grant from the PCA Education Foundation.
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Cement Modification of Clay Soils
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Item Code: RD002
Date of Publication: 1969
Price: $0.00
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A study of the benefits obtained by cement modification of clay soils. Comparisons were made between cement-soil and lime-soil mixtures using 11 different soil samples, four with an AASHTO classification of A-6 and seven with a classification of A-7-6. Additions of 3% and 5% cement by weight to these soils significantly reduced the plasticity indexes and increased the shrinkage limits, cohesiometer values, and unconfined compressive strengths. Reductions in plasticity index by cement treatment were approximately the same as those produced by an equal weight of lime. Strengths of cement-treated A-6 soils were greater than those of A-7-6 soils. In addition, soils treated with cement generally showed higher strengths than those treated with lime. This was particularly evident with Type A-6 soils. This report is also found on DVD021.
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Characteristics and Utilization of Coarse Aggregates Associated with D-Cracking
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Item Code: RD047
Date of Publication: 1976
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Degree of saturation of coarse aggregate and its response to freezing and thawing are important aspects of the problem of D-cracking. Studies have indicated that nondurable material may reach critical saturation when the concrete is in contact only with capillary-held water. Sorption properties and freeze-thaw tests differentiate between durable and nondurable materials. Reducing maximum aggregate particle sizes, as indicated by laboratory freeze-thaw tests, is the most feasible method of improving durability. This report is also found on DVD021.
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Comparative Performance and Cost of In-Service Highway Pavements - I-15 Utah
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Item Code: SN2209a
Date of Publication: 2001
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This report summarizes a study of the long-term performance and costs of concrete and asphalt pavements on Interstate 15 in Utah. Descriptions are given of the orginal pavements, subgrade, and traffic, pavement rehabilitation, service life, and life-cycle cost. Cost and performance data-favor concrete. This report is also found on DVD021.
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Comparative Performance and Cost of In-Service Highway Pavements I-40 Oklahoma
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Item Code: SN2209b
Date of Publication: 2001
Price: $0.00
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This report summarizes a study of the long-term performance and costs of concrete and asphalt pavements on Interstate 40 in Oklahoma. Descriptions are given of the orginal pavements, subgrade, and traffic, pavement rehabilitation, service life, and life-cycle cost. Cost and performance data-favor concrete. This report is also found on DVD021.
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Comparative Performance and Costs of In-Service Highway Pavements I-985 and SR 400, Georgia
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Item Code: SN2209c
Date of Publication: 2001
Price: $0.00
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This report documents a comparative study of the performance and life cycle cost of JPCP and ACP on I-985 and SR-400 in northern Georgia. A general description of the corridors, including location, climatic condition, traffic, and design is provided. The original pavement construction and rehabilitation activities are described and summarized in terms of type, year, and cost. The pavement performance was analyzed using survival analysis and LCCA. The LCCA considered the costs of initial construction and significant rehabilitation, was conducted for analysis periods of 25, 30, 35, and 40 years, and was completed using a 3.77 percent inflation rate, a 7.32 percent market interest rate, and a 3.55 percent discount rate.
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