bluuebunny/crossref_metadata_2025 huggingface dataset:
Long-Term Leaching Performance for Commercially Stabilized Waste
Authors: Perry KJ , Prange NE , Garvey WF
Published: March 2009

Waste stabilization has emerged as one of the frequently required best demonstrated available technology (BDAT) treatment methods for land disposal of hazardous wastes as mandated under the Hazardous and Solid Waste Amendments (HSWA) of 1984. Despite this increasing reliance on stabilization as a final treatment for hazardous wastes, there is little published information on the long-term leaching performance for this type of treatment. Recognizing this, Monsanto began a study in early 1988 to evaluate the effect of elapsed time after treatment for a selected group of four Monsanto wastes, which included metallic and reactive solids. The wastes were sent to six stabilization vendors, who returned treated waste samples to Monsanto for analysis. A Toxicity Characteristic Leaching Procedure (TCLP) extraction was performed on each raw waste sample and on each stabilized waste sample at 28 days (in duplicate) and at 90, 200, 470, and 650 days (single samples) after treatment. The results demonstrated a highly waste-dependent effect of time on the TCLP results. Leachate values for some metallic wastes remained stable over time, and for other metallic wastes, leachate concentrations increased over time. These results suggest that additional scientific and regulatory evaluation of stabilization technologies and treated samples may be required to ensure long-term leaching performance confidence.
Application of Radioactive Waste Solidification Methods to Hazardous Wastes in Italy
Authors: Donato A , Ricci GA
Published: March 2009

The application of radioactive waste solidification processes to industrial hazardous waste (HDW) has been studied. An investigation to identify the most significant HDW types currently produced in Italy was carried out, and samples were collected from various producing industries to use in an experimental solidification program. The solidification processes have been divided into two categories: (1) processes using polymers as binders (polyester resins and urea-formaldehyde), applicable to the solidification of HDW of mixed organic-inorganic nature; and (2) processes using cement, applicable to HDW of inorganic nature.

The applicability of the mentioned solidification processes to some representative HDW was studied by establishing for each the best waste-to-binder ratio. Mechanical strengths and heavy metal releases were then determined. HDW incorporation in cement and in polyester resins is feasible, and the solidified final product satisfies the regulatory requirements. On the contrary, the incorporation in urea-formaldehyde resins is not applicable. The solidification costs have been calculated.
Mixture Design Optimization Considering Three Disposal Options for Solidified Heavy Metal Sludges
Authors: Shin H-S , Kim J-O , Koo J-K , Shin E-B
Published: March 2009

This research evaluated the feasibility of three different disposal options such as landfill, reuse in construction, and ocean disposal for solidified materials containing synthetic heavy metal sludges—copper and chromium. Three factors—binder/sludge, fly ash/binder, and sodium silicate (Na2SiO3) sludge ratios—were investigated in terms of physical and leaching properties. Considering the actual disposal environment, three different leachants, namely, acidic water, distilled water, and seawater, were used in the leaching tests.

The inhibition of cement hydration by copper sludge significantly affected the physical properties of solidified materials. Fly ash additions deteriorated the overall properties of solidified material, but the use of a sodium silicate solution had no significant effect. Leachate characteristics after 24-h extraction were strongly affected by the nature of leachant, and leached metal concentrations were well matched with theoretical solubility according to leachate pH. A comparison of leaching characteristics indicated that acidic water was the most aggressive toward leaching the solidified matrices and that distilled water was slightly more aggressive than seawater. Leachate alkalinity after seawater leaching decreased less than initial seawater alkalinity, which would be caused by carbonate influx and magnesium hydroxide [Mg(OH)2] formation onto solidified matrices.

Results of triplicate tests and statistical analysis indicated that the binder/sludge ratio had the greatest effect on physical properties while the type of leachant had the greatest effect on leaching properties. Mixture design optimization using linear programming was attempted for the economic comparison of three disposal options. As a result, ocean disposal as well as reuse in construction were estimated as the preferred disposal alternatives for solidified heavy metal sludge.
Cement Conditioning of Waste Materials and Polluted Soil Using the GEODUR Process
Authors: Brodersen K , Hjelmar O , Mortensen S
Published: March 2009

In this work, two areas of application of the GEODUR additive in cement stabilization of waste materials have been investigated: stabilization of radioactive contaminated soil and stabilization of municipal solid waste incinerator ash. Preliminary experimental work on a clayey soil contaminated with radioactive cesium and strontium has indicated that the GEODUR process is a technically feasible method for soil solidification. The retarding effects of humic materials in the soil are eliminated by the additive even at low cement contents. The solidified soil is not particularly strong, but has satisfactory water permeability. Retention of cesium is reasonably good, but not as good as for the untreated soil. Retention of strontium is not good but is considerably improved by carbonation. The volume stability during permanent immersion of the solidified products in water is satisfactory, but crack formation during dryout cannot be excluded.

In a parallel experimental investigation of the effect of stabilizing incinerator ash with cement with and without addition of GEODUR it was found that the additive reduces the leachable fractions of copper, zinc, cadmium, and lead. Addition of GEODUR was also found to reduce the rate of release of cadmium, copper, and lead (and possibly zinc) from cement-stabilized incinerator ash in a marine (seawater) environment. Incinerator ash stabilized with 7.4 and 13% sulfate-resistant cement was investigated. It seems likely that application of the GEODUR process in some cases may reduce the amount of cement necessary for stabilization of incinerator ash without sacrificing waste form performance. The results presented are based on a limited number of results from continuing experimental programs which are expected to produce a more complete basis for firmer and more quantitative conclusions.
Development of an In-Line Grout Meter for Improved Quality Control
Authors: Del Cul GD , Gilliam TM
Published: March 2009

Data have been presented which show that electrical resistance of freshly prepared cement-based grouts is linear with respect to grout-mix ratio over a wide range. The data serve to establish the proof of principle for application to the real time measurement of mix ratio utilizing a meter based on the electrical resistance of the grout. The data affirm that special care must be maintained during design and installation to insure that the electrodes are properly sealed.
Summary of Solidification/Stabilization SITE Demonstrations at Uncontrolled Hazardous Waste Sites
Authors: Barth EF
Published: March 2009

Four large-scale solidification/stabilization demonstrations have occurred under EPA's SITE program. In general, physical testing results have been acceptable. Reduction in metal leachability, as determined by the TCLP test, has been observed. Reduction in organic leachability has not been determined since only low levels of organics have been leached from the raw waste utilizing the TCLP test.
Contributions of Lysimeter Data to the Development of Site Specific Performance Assessment Plans
Authors: Rogers RD , McConnell JW , Jastrow JD , Wickliff DS
Published: March 2009

Accurate data on the long-term performance of radioactive wastes in a disposal system are becoming a necessity in part because of restrictive federal and state regulations that are being promulgated. Data on the performance of buried radioactive waste forms can be obtained from lysimeter arrays. Lysimeters are ideal instruments for the acquisition of actual field test data. When properly designed and operated, lysimeters can be used to isolate and then study soil/waste systems under actual environmental conditions. The complexity of interactions occurring under field conditions can never be completely duplicated by standard laboratory testing. This paper provides data from two instrumented, operational lysimeter arrays containing waste forms fabricated with highly loaded exchange resin materials. The lysimeters have been in operation for five years and have been providing data for both meteorological events and radionuclide content of percolating water for the past four years. This paper provides data obtained from the lysimeters, a discussion of the data, and a manipulation of the database for calculating some code parameters that can be used as input into codes used to verify performance of buried radioactive waste forms.
Performance Appraisal of Full-Size Radioactive Waste Packages
Authors: Nominé JC , Billon A
Published: March 2009

Before final storage in a subsurface site, each kind of encapsulated or immobilized radioactive waste has to be recognized as acceptable for this situation. To reach this goal, French radioactive waste policy recommends an exhaustive characterization of radioactive packages. Complying with this regulation, each processing step, from the waste production to ultimate storage (identification, sorting out, conditioning, transporting, storage, and so on) necessitates a knowledge of specific properties. Among them are physical and mechanical characteristics, confinement characteristics, and behavior in relation to the stability and the aging of the embedded wastes. To give an overview, examples of results with comments will be presented and compared.
Modification of the EXCO Test Method for Exfoliation Corrosion Susceptibility in 7XXX, 2XXX, and Aluminum-Lithium Alloys
Authors: Lee S , Lifka BW
Published: March 2009

The EXCO test (ASTM G 34) is widely used to predict long-term exfoliation corrosion of high strength aluminum alloys in seacoast and other service environments. Recent experience has shown that the EXCO test does not always accurately predict the resistance of 7X50 and 2024 products processed to different degrees of resistance to exfoliation. The test also severely underestimates resistance to exfoliation of 2090-T8 products.

For 7X50 alloys, the standard EXCO test is too corrosive for materials in T7 types tempers. This unrealistic corrosion occurs during the first 24 h of the test, during which time the solution is highly acidic, starting at pH 0.4 and gradually stabilizing at pH 3.2. Tests in a preconditioned EXCO solution, prepared by exposing a piece of 7150 plate in fresh EXCO solution for 24 h to eliminate the period of low pH, showed better correlation with atmospheric test results. Subsequent chemical analyses of this preconditioned solution led to a modified EXCO solution capable of distinguishing the different levels of resistance to exfoliation that are inherent in the three commercial tempers (T6, T76, and T74). This modified solution contains 600 mg/L of aluminum ion plus 4M (142 g/L) chloride and 0.6M (37.2 g/L) nitrate concentrations, and has a pH of 3.2.

When conducted at a temperature of 52°C, the modified EXCO solution accurately reflected the performance of 2090 and 2024 alloys in a seacoast atmosphere.
Exfoliation Corrosion Testing of Aluminum-Lithium Alloys
Authors: Thompson JJ
Published: March 2009

A study was performed comparing the corrosion resistance of new aluminum alloys in shipboard environments with accelerated laboratory corrosion test environments. The aluminum-lithium (Al-Li) alloys tested were 2020-T651, 2090-T8E41, and 8090-T851. For comparison, 7075 aluminum was tested in the exfoliation susceptible T651 temper and the resistant T7351 temper. Shipboard exposures were performed aboard aircraft carriers deployed to the Mediterranean Sea, and to the Indian Ocean during the monsoon season. Accelerated laboratory tests performed were EXCO (ASTM G 34-86), sulfur dioxide salt fog (ASTM G 85.A4-85), and MASTMAASIS (ASTM G 85.A2-85).

After shipboard exposure, the aluminum-lithium alloys in commercial tempers exhibited pitting corrosion similar to 7075-T7351. Aluminum alloy 7075-T651 exhibited severe exfoliation. During a mild shipboard exposure in which 7075-T651 developed superficial exfoliation, 8090-T651 exhibited moderate exfoliation demonstrating these alloys are not inherently exfoliation resistant.

Standard accelerated laboratory tests were effective predictors of performance in 7075 aluminum, but were not as effective for aluminum-lithium alloys. For 7075 aluminum, shipboard behaviors were reproduced in sulfur dioxide and MASTMAASIS salt fog after 3 to 4 weeks, and in EXCO after 48 h. For commercial Al-Li alloys, the standard accelerated laboratory tests did not reproduce shipboard exposure results.
Procedures and Fixtures for Removing, Capping, Handling, and Testing Masonry Prisms and Flexural Bond Specimens
Authors: Jones WD , Butala MB
Published: March 2009

Martin Marietta Energy Systems, Inc. (MMES), is currently assessing the safety of the Oak Ridge Y-12 Plant. Many of the facilities at this plant are constructed using unreinforced hollow clay tile walls (HCTWs). In the spring of 1990 a testing program that includes in situ, laboratory, and shake table tests, and nondestructive examinations was initiated.

This paper presents the techniques used for removing, capping, and handling masonry prism specimens for testing normal and parallel to the bed joints. It also presents similar techniques used for removing, handling, and testing flexural bond masonry specimens. How these techniques can be used to obtain consistent test results and why they are required to meet relevant ASTM standards is described. These fixtures can also be used for fabrication of laboratory test specimens.
Making Diaphragm Wall Joints Watertight with the CWS System
Authors: Vanel P
Published: March 2009

Diaphragm walls are discontinuous structures composed of individual panels. Making the joints between the panels watertight has been a problem for decades. The CWS system is a technique that allows the construction of geometrically well defined joints equipped with watertight devices such as waterstop blades.
Slurry Trench Cut-Off Walls for Environmental Pollution Control
Authors: Grube WE
Published: March 2009

Cut-off walls built by the bentonite-clay slurry trench technique are designed and installed to control flow during site remediation at hazardous waste sites. Non-aqueous phase liquids (NAPL's) in the site groundwater are being sought in remedial investigations as critical contaminants which are likely to significantly affect cut-off wall design and performance. Testing of backfill permeability with these liquids is necessary to ensure that the backfill will resist degradation at elevations where they occur in the groundwater. Recent research has focused on the impact of ion diffusion through the completed barrier. Plastic concrete, attapulgite clay slurries, and biopolymer slurries have been reported in use to meet job-specific requirements. Field test cells, several tens of feet in dimension, and extending to the expected depth of the total cut-off all structure, are increasingly being required by clients as pre-construction hydraulic performance demonstrations. Pump-down measurements applied to these cells provide data from which the permeability of the walls, built with full-scale field equipment, can be calculated. Hydraulic fracturing, verification of bottom-key effectiveness, long-term permeability performance, and significance of diffusion of solutes through the completed groundwater barrier remain areas of sparse published data. This paper reviews environmental slurry wall experience since the early 1980's, with emphasis on performance evaluation.
Composite Barrier Slurry Wall
Authors: Cavalli NJ
Published: March 2009

For decades systems utilizing various types of vertical flow barriers have had to be constructed to contain polluted groundwater or leachate from contaminated sites or waste disposal areas. Many of the vertical barriers used in these systems were implemented and were assumed, or designed to maintain their impermeable and barrier qualities over the long term. In the years that have passed little data has been available for comparison of predicted long-term effectiveness of vertical barriers with actual results, thus long-term performance of vertical barriers in chemically and physically agressive environments remain uncertain and unproven. Composite barriers are an attempt to overcome these inadequacies and provide a database to go forward.
Using Slurry Walls to Protect an Historic Building: A Case Study
Authors: Garvin RG , Boward JF
Published: March 2009

Slurry Wall construction was used in the construction of a five-level underground parking structure adjacent to a settlement-sensitive historic building. The slurry wall minimized ground disturbances and maintained groundwater levels in the soil supporting the building. Employed for both temporary and permanent excavation support, the slurry wall was designed as the permanent perimeter foundation wall of the parking structure. Geotechnical instrumentation was installed to monitor ground movements during excavating operations and construction. Groundwater levels were also monitored to evaluate the performance of the wall in minimizing groundwater drawdown in critical areas. The instrumentation data confirmed that the wall performed as intended; it successfully supported the excavation and new building without disturbing the historic structure.
Performance of an Internally Braced Slurry-Diaphragm Wall for Excavation Support
Authors: Bono NA , Liu TK , Soydemir C
Published: March 2009

This paper presents the construction performance of an internally braced diaphragm wall constructed by the slurry trench method at a waterfront site on the Boston Harbor in Massachusetts. Due to the proximity of an existing building, waterfront structures and the harbor, as well as the unfavorable subsoil conditions, a cross-lot bracing system was selected for excavation support. The earth support system was instrumented by inclinometers and strain gages, and the existing abutting building was monitored by settlement reference points. Instrumentation data allowed monitoring of performance of the excavation support system as well as settlements in the existing adjacent building during the foundation construction.

The performance data indicated significantly unsymmetrical lateral displacements of the opposite diaphragm walls resulting from the unequal loads imposed by the building surcharge on one side as well as the limited soil mass on the opposite harbor side. Also, the daily collected data made it possible to take quick remedial action on the lateral support system at the time of a critical incident.
Assessing the Role of Steel Corrosion in the Deterioration of Concrete in the National Infrastructure : A Review of the Causes of Corrosion and Current Diagnostic Techniques
Authors: Hertlein BH
Published: March 2009

Concrete forms a major component of the national infrastructure. The interaction between corrosion of embedded steel and deterioration of concrete is of concern to the engineers involved with infrastructure maintenance. If an effective repair and maintenance strategy is to be planned, it is important to understand the forms and causes of deterioration and corrosion damage in concrete structures. Equally important is an understanding of the range of test methods available to diagnose the cause and determine the extent of such damage.
The Influence of Fiber Waviness on the Compressive Behavior of Unidirectional Continuous Fiber Composites
Authors: Highsmith AL , Davis JJ , Helms KLE
Published: March 2009

The influence of fiber waviness and matrix nonlinearity on the compressive behavior of continuous fiber composites is studied. A micromechanics model based on the kinematics of the fibers has been developed to predict the behavior of unidirectional composites with initially wavy fibers under compressive loads. The initial waviness has been idealized as sinusoidal. Nonlinear shear behavior of the matrix has been included. Because the shear strain in the matrix is a function of position, the deformed shape of the fibers differs from the initial shape. Therefore, the deformed fiber shape is represented by a sine series.

Fiber waviness and matrix shear properties have been determined experimentally for T650-42/Radel C under several conditions. These experimental data have been used as input into the analytical model. Predicted compressive response is in reasonable agreement with experimental data.
Analysis of Composite Material Containing Defects
Authors: Frankle RS , Jones DR , Roberts BL , Shusto LM
Published: March 2009

This paper describes work performed by Failure Analysis Associates, Inc. (FaAA) to develop capabilities for quantitative analysis and evaluation of parts containing defects. The work was conducted for Boeing Aerospace under the Astronautics Laboratory NDE Data Application Project (F04611-86-C-0080). In this project, FaAA used a finite element structural analysis code to predict the response of carbon-carbon involute rings that were intentionally fabricated with wrinkles and overstaged plies. Analytical techniques for modeling the effects of the defects were evaluated. The finite element analysis predictions compared favorably with data from hoop tension tests of the rings. A computer code was developed to use digital nondestructive evaluation (NDE) data automatically to define spatially varying material properties required by finite element analysis. The code provides a practical mechanism for automatically including the effects of defects in the analysis of actual hardware. The results of this effort demonstrate promising capabilities for the analysis of composite parts containing defects.
Delamination Failure in a Unidirectional Curved Composite Laminate
Authors: Martin RH
Published: March 2009

Delamination failure in a unidirectional curved composite laminate was investigated. The curved laminate failed unstably by delaminations developing around the curved region of the laminate at different depths through the thickness until virtually all bending stiffness was lost. Delamination was assumed to initiate at the location of the highest radial stress in the curved region. A closed form curved beam elasticity solution and a two-dimensional finite element analysis (FEA) were conducted to determine this location. The variation in the strain energy release rate, G, with delamination growth was determined using the FEA. A strength-based failure criterion adequately predicted the interlaminar tension failure that caused initial delamination onset. Using the G analysis, the delamination was predicted to extend into the arm and leg of the laminate, predominantly in Mode I. As the initial delamination grew around the curved region, the maximum radial stress in the newly formed inner sublaminate increased to a level sufficient to cause a new delamination to initiate in the sublaminate with no increase in applied load. This failure progression was observed experimentally.
Deterioration of Thermal Insulation Properties of Extruded Polystyrene: Classification and Quality Control System in Sweden
Authors: Sandberg PI
Published: March 2009

In the process of assessing design values for thermal conductivity of insulating materials, knowledge of the time-dependent deterioration of the insulation performance is important. Extruded polystyrene is affected by changes in the composition of the gas mixture in the cells (normally referred to as ageing) and in some applications by moisture accumulation, both mechanisms resulting in a higher thermal conductivity.

In the Swedish quality control system the determination of thermal conductivity is carried out 91 ± 7 days after manufacture. Part of the ageing has by then already taken place, and the rest of the ageing during the life span of a building is taken care of by a specified addition (Δλa) to the laboratory value in the assessment of the design value. The more ageing that takes place before the determination of the thermal conductivity, the more accurate the design value will be. Different ways of accelerating the ageing have been discussed. This paper describes a method of acceleration by cutting the specimens into thin slices. It is shown that, by making use of this method, no extra addition allowing for the ageing under service conditions is needed (i.e., Δλa = 0).

The paper also deals with moisture accumulation in soil insulation and inverted roofs. The moisture corrections (Δλm) in the classification system are given. A method for acceleration of the moisture pickup and correlation to in situ measurements as well as a theoretical model for predicting moisture accumulation are described. Finally, effects of moisture on thermal conductivity are discussed.
A Dynamic Test Method for Determining Transfer Function Coefficients for a Wall Specimen Using a Calibrated Hot Box
Authors: Burch DM , Zarr RR , Licitra BA
Published: March 2009

This paper describes a dynamic test method for determining transfer function coefficients (TFCs) for a wall specimen using a calibrated hot box (CHB). In this method, a wall specimen is installed between the climatic and metering chambers of a CHB. After a steady specimen heat transfer rate is attained, the air temperature in the climatic chamber is quickly ramped from an initial to a final temperature level in a linear manner. The final temperature level is maintained until a new steady specimen heat transfer rate is attained. The metering chamber is maintained at a steady indoor condition and is used as a calorimeter. The transient heat transfer rate at the inside surface of the wall specimen is determined at hourly time steps from an energy balance of the metering chamber. The poles and residues for a ramp analytical solution are derived by analyzing the measured specimen heat transfer response. The ramp analytical solution is subsequently used to form a triangular pulse from which TFCs are derived.

The dynamic test method was conducted on a masonry wall. Empirical TFCs derived by the test method predicted the diurnal performance of the wall specimen with good agreement. In fact, the results predicted by empirical TFCs tracked the measured results as closely as an analytical model.
The Development of a Simple Instrument for Measuring Pavement Roughness and Predicting Pavement Rideability
Authors: Janoff MS , Hayhoe GF
Published: March 2009

Based on the results of recent research, it is possible to develop performance specifications for a simple instrument that would measure profile-type roughness in only one wheelpath—instead of two, as in the profilometer—and which would compute a roughness index that is as highly correlated with pavement rideability measurements as the roughness indexes derived from the full profile.

This paper summarizes the results of the research that led up to the development of these specifications, describes the potential accuracy and validity of this instrument in measuring pavement roughness and predicting rideability—including comparisons with a profilometer—and summarizes its design specifications.

This instrument would retain the advantages of the profilometer in terms of accuracy and validity in predicting pavement rideability from pavement roughness measurements, while also retaining the advantages of a response-type roughness measuring system in terms of low cost, ease of use, and data analysis.
Some Surface Roughness, Loss, and Slipperiness Characteristics of Unpaved Roads
Authors: Paige-Green P
Published: March 2009

An extensive investigation into the performance of materials used in wearing courses for unpaved roads in southern Africa has recently been completed. This involved the routine monitoring of 110 sections of selected gravel roads covering a range of material types, climatic regimes, traffic volumes, and road geometrics. Monitoring involved the routine measurement of road roughness, gravel loss, corrugation and rut development, and a routine description of the surface condition. This paper briefly describes the results of the roughness, gravel loss, and slipperiness investigations. Models for the prediction of roughness and gravel loss are described and compared with models developed in other countries. Significant differences between the models are noted. The investigation into the slipperiness of unpaved roads is described, and the slipperiness when dry is shown to be directly related to the grading and plasticity of the material.
Surface-Deterioration Resistance of Concrete Pavement Materials
Authors: Fwa TF , Paramasivam P
Published: March 2009

Surface deterioration is found to have considerably reduced the useful service life of many concrete pavements in Singapore. This paper describes the development of a rotating-drum test to evaluate relative surface-deterioration resistance of different concrete pavement materials. Experimental observations indicated that a satisfactory simulation of field-deterioration process was achieved. The emphasis of the test program reported is placed on the critical initial breakdown of pavement surface that seriously affects pavement rideability. The test method was found sensitive to variation in the properties of materials tested. Test results showed that surface deterioration of concrete pavements can be improved by reducing water: cement ratio, by selecting the proper fine aggregate gradation, or by adding steel fibers.
Influence of Road-Surface Roughness on Vehicle Operating Costs: Reviewing the Evidence from Developing Countries
Authors: Harrison R
Published: March 2009

The paper describes some features of the vehicle operating cost/road-roughness relationships reported in the major international research studies from 1972 to 1986. This research is characterized by the use of road-surface roughness devices, fleets of experimental vehicles to measure fuel consumption, large-scale surveys of vehicle operators, improvements to speed and fuel modeling, and the development of user-friendly economic evaluation models. All studies report significant effects on operating costs following changes in surface roughness. The issues of calibration, new vehicle technologies, and extrapolation of study results are then discussed. The paper concludes by characterizing the main features of the research studies and shows the rise in operating costs attendant on allowing surface conditions from deteriorating to high levels of roughness.
Comparison of Slug Test Methodologies for Determination of Hydraulic Conductivity in Fine-Grained Sediments
Authors: Herzog BL , Morse WJ
Published: March 2009

Slug tests were conducted on four lithologic units at a waste disposal site in southwestern Illinois. All tested units were fine-grained glacial tills that had laboratory-determined hydraulic conductivity values between 10-9 and 10-6 cm/s. A total of 37 field tests of hydraulic conductivity were run in 29 open-hole piezometers, with some tests lasting up to a year. The piezometers were oriented both vertically and at a 45° angle to test the effects of possible vertical fractures on hydraulic conductivity.

All slug test results were analyzed using three different methods. The methods selected were those of Cooper, Bredehoeft, and Papadopulos; Hvorslev; and Nguyen and Pinder. The geometric mean values for each geologic unit determined by all three methods were within an order of magnitude and well within one standard deviation.

All three methods could not be applied to all data with the same degree of reliance. This is to be expected since each method has different underlying assumptions. However, all data did fit at least one theoretical curve very well. The importance of these results is twofold: (1) any of the three methods can produce reliable results if properly applied, and (2) data that appear to be unusable by one method may be usable by changing to another method of analysis.
Petrographic Examination of Aggregate and Concrete in Ontario
Authors: Rogers CA
Published: March 2009

Petrographic examination of aggregate and hardened concrete has been conducted by the Ministry of Transportation since the late 1940's. There were problems in communicating results of petrographic examination of aggregates to engineers. This resulted in the development of the “Petrographic Number” (P.N.) as a way of expressing the quality of coarse aggregate. Four quality categories are recognized: good aggregate (factor 1), fair (factor 3), poor (factor 6), and deleterious (factor 10). The Petrographic Number is calculated by multiplying the percentages of each rock type by the appropriate factor. The products are then added up to arrive at the P.N. The higher the P.N., the poorer the quality of the aggregate. A perfect aggregate would have a P.N. of 100. Petrographic examination is conducted on sand using automated equipment. The percent of deleterious (mica, shale) or alkali-reactive components (chert, glass) is reported. Petrographic examination of concrete is also conducted. Over the years, many problems have been investigated, such as: firedamaged concrete, frozen concrete, concrete damaged by alkali-aggregate reactions of various types, damage by freezing and thawing, causes of low strength and retarded concrete. In addition, petrographic examination has been used to detect additions of non-standard components to Portland cement.
The Magic of Investigative Petrography: The Practical Basis for Resolving Concrete Problems
Authors: Erlin B
Published: March 2009

Investigative petrography, based upon past and present applications, includes information developed using a broad variety of analytical methods. The analytical data needed to be obtained is initially identified using microscopical evaluations. That initial data, plus subsequently developed data, evaluated in the light of the nature of materials behavior, provides a better understanding of causes of materials performance.

Two case histories are presented which follow analytical investigative procedures used to identify the causes; in one case, of low concrete strengths, and in the other, of extensive cracks and curling of slabs-on-grade.

The low strengths were caused by exposure of the concrete to sub-freezing temperatures. The petrographic studies provided evidence of the early freezing, exonerated other factors, and subsequent studies for admixture contents provided evidence linking the admixture dosage to the freezing phenomenon. The cracks and curling resulted because of interference of a chemical component of an admixture to the timely hydration of the expansive component of Type K shrinkage-compensating cement. The petrographic procedures used to identify the causes of these problems are presented.
Nitric Acid Induced Degradation of High Density and Linear Medium Density Polyethylene: Physical Property Sensing Techniques
Authors: Tisinger LG , Carraher CE
Published: March 2009

The paper addresses the way in which analytical techniques may be used to characterize changes in the microstructure of geomembranes due to aggressive chemical environments. For this work, linear medium density polyethylene geomembranes and high density polyethylene geomembranes were exposed to 70% nitric acid for 2, 6, 8, and 10 days at 50°C. Tensile properties were measured after each exposure period. Degrees of crystallinity, onset of decomposition temperature, and infrared analyses were conducted before and after 10 days' exposure to nitric acid. Both materials displayed degradation and appear to have been similarly affected by the aggressive chemical environment.
Brittle Fracture in Polyethylene Geomembranes
Authors: Peggs ID , Carlson DS
Published: March 2009

The common concept of polyethylene in geomembrane form is that of a compliant ductile material that yields at 12% elongation but will actually break only after reaching 800% or more elongation. This is so, but over extended periods of time polyethylene will also fail by brittle cracking at essentially zero elongation.

Within two years of installation, brittle cracks have developed in geomembrane liners exposed on the side slopes of liquid impoundments. Such cracking has occurred at stresses well below the yield stress of the material.

The characteristics of brittle fractures with respect to the locations where they occur, how they are initiated, how they propagate, and what can be done to prevent them are discussed in this paper.
Microstructural Analysis of a Soil/Geotextile System
Authors: Mlynarek J , Rollin AL , Lafleur J , Bolduc G
Published: March 2009

The rearrangement of the soil in contact with a geotextile is of basic importance in the behavior of engineering filtration systems. The paper presents a microscopic method for the analysis of soil/geotextile systems. This method supports filtration tests to explain experimental and field behaviors. A morphometric method was applied to analyze the used geotextiles and the microstructure of the soil layer upstream of the filters. In order to observe the natural filter structure and the clogging level of the filter, soil/geotextile samples were encapsulated in an epoxy resin, cross-sectioned, and analyzed under a microscope. The filtration laboratory tests have been performed on in situ soils to supplement microscopic analysis to forecast filtration behavior of geotextiles. Using both techniques, the time-dependent phenomena taking place at the soil/geotextile interface and the clogging mechanisms can be identified. In this paper, the microphotographs of soil/geotextile systems and their water permeabilities as a function of filtration time are presented.
Mix Design Practices for Cold In-Place Recycled Pavements
Authors: Scholz T , Hicks RG , Allen D
Published: March 2009

Since 1984, the Oregon State Highway Division has constructed 724 km (450 centerline miles) of cold in-place recycled pavements. During this period, an intensive study was undertaken by the Oregon Department of Transportation (ODOT) and Oregon State University (OSU) with the following purposes: 1. To develop an improved mix design procedure for cold in-place recycled pavements. 2. To evaluate the structural contribution of cold in-place recycled pavements. 3. To develop improved guidelines and specifications for the construction of cold in-place recycled pavements.

This paper summarizes the development of a mix design process and describes the early procedures used and their limitations.

The first section of the paper describes the recycling process used during the 1984–1988 period. The second part of the paper describes the evolution of the mix design process used during this period. It describes the steps needed to estimate the emulsion content from properties such as RAP gradation, residual asphalt content, and asphalt properties (penetration and viscosity). Also described are the mix design criteria developed to date (stability, modulus, etc.). The third part describes the expected ranges in strength properties (stability, modulus, etc.) for cold recycled mixes.

The last part of the paper presents significant conclusions from the work performed to date as well as recommendations for further study.
Asphalt Emulsion Slurry Seal and Wheelpath Inlay
Authors: Baker RF
Published: March 2009

This report documents the development of a slurry seal and wheelpath inlay study. The objective of this study is to develop quick inexpensive procedures to improve skid resistance, extend the useful life of a pavement, and to reduce wheelpath rutting on bituminous concrete pavements.

A two-course asphalt emulsion slurry seal was constructed on two sites to monitor the extension of useful pavement life and improved skid resistance. The slurry seal increased the useful pavement life for at least three years and improved the skid resistance by approximately 30%.

A wheelpath inlay was constructed on a severely rutted bituminous concrete pavement. Rut depth and skid resistance data were taken before and after construction. The inlay appears to offer an effective, alternate, less costly procedure for correcting wheelpath rutting.

Recommendations are presented for the use of the slurry seal and the wheelpath inlay.
Analysis and Interpretation of Aircraft Component Defects Using Quantitative Fractography
Authors: Goldsmith NT , Clark G
Published: March 2009

Quantitative fractography techniques have been in use at the Aeronautical Research Laboratory (ARL), Melbourne, Australia, for more than 15 years, and they have been developed into a specialized facility for deriving crack growth histories from fracture surfaces. This capability has played a fundamental role in a number of pioneering life extension programs which have permitted the continued operation of several aircraft types in current service with the Royal Australian Air Force (RAAF). The increasing RAAF demand for advanced fractography has required the development over a number of years of computer-based semiautomated data acquisition and data processing facilities for fractographic analysis; these developments have permitted a significant improvement in the speed with which fracture surfaces may be analyzed and are now used routinely in ARL's quantitative fractography.

This paper describes current ARL activities in the use and further development of quantitative fractographic techniques and the specialized facilities employed to derive and process data from fracture surfaces observed by both scanning electron microscopy and optical microscopy. The results able to be obtained are illustrated by reference to case histories of defects in components from service aircraft, from full-scale component tests, and from laboratory test samples. Procedures for minimizing or overcoming some of the difficulties associated with interpretation of fracture surface markings are discussed. The paper also describes the way in which fracture mechanics concepts need to be used in conjunction with fracture surface analysis to achieve a correct understanding of the crack growth history. In particular, some empirically based approaches developed for interpolation and extrapolation of incomplete crack growth histories may now be understood by reference to fracture mechanics concepts. Finally, current and future developments in fracture surface analysis are discussed, with particular reference to the benefits to be gained by the introduction of modern image processing and image enhancement techniques.
Current and Future Neutron Radiologic NDT Standards
Authors: Brenizer JS
Published: March 2009

Two groups are active in producing standards which are used in neutron radiology (NR) activities within the United States. On the national level, ASTM has three standards which address the neutron radiography method: ASTM Practices for Thermal Neutron Radiography of Materials (E 748), ASTM Method for Determining Image Quality in Direct Thermal Neutron radiographic Testing (E 545), and ASTM Method for Determining the L/D Ratio of Neutron Radiography Beams (E 803). The International Organization for Standardization (ISO) has a working group which is developing three standards that also address the neutron radiography method. No ASTM or ISO standards exist for the neutron radioscopic NDT method.

Future ASTM standards will address the neutron radioscopic method, neutron radiographic dimensioning, and neutron radiologic system characterization. It is expected that similar efforts will be undertaken in ISO. Given the relatively small community providing neutron radiologic NDT services, international cooperation already in place will most likely continue to grow. This paper reviews current and future trends in NR standards and the impact of these standards on the world market.
Present and Future NDT Standards for Liquid Penetrant and Magnetic Particle Testing
Authors: Fenton JD
Published: March 2009

Consider four basic types of documents—guides, practices, references, and specifications. The documents written by ASTM E07.03 on Penetrant and Magnetic Particle Methods have traditionally been guides, practices, and references. This subcommittee will now include specifications. Guides and practices instruct or guide the user, define good industry practices, and always give the user every possible option from which to select. They supply detailed how-to information to the user on how to apply the process. The references are a collection of graded anomalies that furnish the engineer with a very useful tool by which he can define acceptance criteria. A specification is a control document that establishes the basic parameters within which the process must be controlled. They are thou shall documents and supply very little howto information.

In order to call out guides and practices on an engineering drawing, in a specification, or in a contract, many qualifying statements are required, making these documents undesirable for this purpose. Specifications supply a minimum amount of instructions or how-to information—they define the parameters within which the process is applied or controlled. There are, basically, three types of specifications: (1) those that control the process, (2) those that establish the acceptance criteria, and (3) those that do both.
NDT Standards from the Perspective of the Department of Defense
Authors: Strauss B
Published: March 2009

This presentation illustrates the interaction of the DoD non-Government Society (NGS) bodies in the area of NDT. The adoption process for NGS will be outlined including the criteria for adoption, what adoption means, and the advantages of DoD/NGS interaction.

The tasks of the DoD's Standardization Program Plan for NDT will be described along with DoD's efforts on a Joint Army, Navy, Air Force (JANNAF) NDE Subcommittee and on an international standardization group (America, Britain, Canada, and Australia) called the Quadripartite Working Group on Proofing, Inspection, and Quality Assurance.
U.S. Participation in the Development of International Standards for Nondestructive Testing
Authors: Mordfin L
Published: March 2009

It is important to the U.S. balance of trade that international standards for nondestructive testing (NDT) be compatible with the practices used in this country. This need is becoming more critical as the European Community approaches its goal of a single market with uniform standards. Unfortunately, the private sector of the U.S. economy does not appear to have adequately recognized this need, nor has the public sector faced up to it, so that U.S. participation in the development of international standards for NDT has been less than adequate. The nature and the status of this participation are explained and discussed.