bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact Damage Characteristics of Bismaleimides and Thermoplastic Composite Laminates
Authors: Dan-Jumbo E , Leewood AR , Sun CT
Published: December 2008

Impact damage in laminates of four different composite systems was investigated. These composite systems included two thermoplastic-based composites (PEEK and Torlon) and two epoxy-based composites (toughened and brittle BMIs). At low impact ve locities, PEEK (polyetheretherketone) and Torlon composites showed significantly less matrix cracking and delamination and greater strength retention capability than the two epoxy-based composites. However, beyond a certain threshold velocity, the thermoplastic composites experienced a sudden drop in flexural strength, more so than the epoxy-based composites.Between the two epoxy-based systems, the toughened BMI composite exhibited much better impact resistance properties.
Delamination Damage in Central Impacts at Subperforation Speeds on Laminated Kevlar/Epoxy Plates
Authors: Malvern LE , Sun CT , Liu D
Published: December 2008

An experimental research program has shown that in central impacts at normal incidence by small hard impactors at subperforation speeds on continuous-filament fiberreinforced, laminated composite plates with brittle matrices, the major damage is delamination at the interfaces between unidirectionally reinforced layers of different orientation. This is accompanied by some matrix cracking between the fibers of the layers.

Composites with three kinds of fibers (glass, Kevlar, and graphite), each in a brittle epoxy matrix, have been investigated. This paper reports new results on Kevlar and compares them with some previously published results on glass and graphite. Postimpact visual examination of the semitransparent glass and Kevlar laminates revealed the extent of the delamination.

Relationships between projected delamination area and the kinetic energy imparted to the plate are reported. For those plates where the overlapping delaminations could be resolved and the total delamination area could be determined, the evidence supports the assumption of a single linear relation between total delamination area and imparted kinetic energy for each system observed at these subperforation speeds, but there is a limited amount of this kind of data available. Bending strength and stiffness reductions of the damaged panels are also reported.
X-Ray Permeability of Corrosion Products as a Measure of the Rate of Corrosion of Rebars and of Prediction of Concrete Cracking
Authors: Skoulikidis T , Marinakis D , Batis G
Published: December 2008

Normalized reinforced specimens were placed in 3.5% circulating sodium chloride (NaCl) solution (25°C) under a +850-mV anodic charge. At several time intervals on all of these specimens X-ray radiographies were taken focused on the rebars and on the concrete, and the specimens were placed again in the solutions. Measurements were taken for four months. Because of the direct lowering of the pH in the interface rebar-concrete, the pure electrochemical character of the corrosion overcomes the carbonation, and the concrete cracking is mainly and directly caused by the formation of corrosion products. It was also proved by electron probe micro-analysis (EPMA), a solid state diffusion of Fe2+ through the concrete. It was found that during the exposure the permeability of X-rays in the corrosion products decreases because of mechanical stresses. It is possible to follow the evolution of the corrosion products by X-rays and from their permeability to predict the cracking of the concrete caused by the formation of corrosion products.
Terra Theraic and Magnesium Oxide with Induced Defects as Additives on Concrete for the Protection of Rebars
Authors: Skoulikidis T , Marinakis D , Batis G
Published: December 2008

Normalized concrete specimens, blank and with 4% Terra Theraic (natural material of volcanic origin) or 4% magnesium oxide (MgO) with induced defects (SIMAC) were placed in renewed seawater, and the weight loss measurements of the rebars were taken. The same measurements were taken on the same type of specimens under cathodic protection (−850 mV), protected with our method of needle-diodes or under anodic charge (+850 mV). Some measurements were also taken for specimens immersed directly in the sea by the aid of an experimental raft. Protective properties are presented in a table, and it follows from these findings that the two Greek additives are adequate for a good protection of the rebars. The corrosion in the ocean for a short immersion period is lower than in the laboratory (same seawater) because in the laboratory we have no fouling on the specimens, which in the ocean retards the corrosion by the formation of a biological membrane.
Recommendations for the Development of a Residential Energy Standard
Authors: Cardenas TJ , McBride M , Barney G , Wilcox B , Johnson A
Published: December 2008

In June 1983, the American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) Standards Committee appointed an ad hoc committee to revise Standard 90 for Residential Buildings. The charge to the ad hoc committee was to start the technical thinking process for the creation of a separate ASHRAE Standard 90 for residential buildings and to make recommendations to the ASHRAE Standards Committee as to how such a standard might best be produced.

This paper discusses the elements of the technical review process which included a quantitative assessment of the envelope requirements of American National Standards Institute (ANSI)/ASHRAE/Institute of Environmental Sciences (IES) Standard 90A-80 and comparisons between this standard and to the requirements of other standards and energy conservation guidelines.

During the review of Standard 90A-80, many requirements were identified that should be incorporated into the development of a new residential standard. In this regard, criteria for the technical and economic basis of a residential standard are outlined and discussed.

Finally, recommendations for the development of a methodology for producing a new data base for residential building envelopes, the means for updating the new data base in the future, new simpler compliance procedures, and more accurate trade-off compliance procedures are presented.
A Method for Measuring Heat Loss from Underground Heat Distribution Systems
Authors: Kusuda T , Fang JB , Ellis WM
Published: December 2008

A simple procedure to obtain the in situ determination of heat loss from an underground heat distribution system is described. The proposed procedure for estimating the heat loss from underground heat distribution systems consists of making a series of temperature and thermal conductivity measurements on the ground grid in the vicinity of the pipe system and deducing the heat loss by statistically determining the parameters of a mathematical model using the gathered data. Verification of the procedure was tested in a simulated scale model of an underground system using an insulated sandbox. The scale model is a two-pipe system buried 0.3045 m (12 in.) below the top surface of a 0.66-m (26-in.)-wide, 0.71-m (28-in.)-high, and 1.22-m (48-in.)-long sandbox. The test pipes are two electrically heated steel pipes having an outside diameter of 3.37 cm (1.325 in.). The walls of the sandbox are insulated by 5.08-cm (2-in.)-thick expanded polystyrene board. The heat loss measurements from this simulated underground heat distribution system were obtained for pipe surface temperatures of 66°C (150.9°F), 93.8°C (200.8°F), and 149.2°C (300.7°F) for three different sand moisture contents (dry, 10%, and 13%). Relatively good agreement was obtained between the measured electrical power input to the test pipes and the system heat loss estimated by the sand temperature profile around the pipes and sand thermal conductivity measured by the thermal needle technique. The paper also describes an application of the technique to a field measurement conducted at the James Madison University, Harrisonburg, Virginia.
Prevention of Common Pitfalls Through Engineered Specifications and On-Site Review
Authors: Wartan WJ
Published: December 2008

Poorly engineered specifications have a negative effect on thermal insulation systems. The availability, maintainability, and serviceability of piping and equipment are greatly affected by improper selection of thermal insulation materials and systems. System and equipment design criteria, that is, operating conditions including geographic, local, and environment, must be considered for each specific project.

The specification on file that was successfully used on a previous project at another time and at another location may not always be a wise choice. It is imperative that the manufacturer's literature be reviewed before insulation materials and accessories are specified, to preclude their use beyond the manufacturer's prescribed limits. Referencing of ASTM standards in the specification is a useful means of establishing a level of conformance and quality.

On-site reviews are a useful tool for review of the work and its conformance to the specification. The reviews must occur on a timely basis as the work progresses.

Provisions must be made to resolve problems that may arise because of construction restraints during the progress of the work. Close liaison with the insulation contractor will preclude guesswork and the resulting cost of rework.
Field Measurement of the Thermal Resistance of Office Buildings
Authors: Fang JB , Grot RA
Published: December 2008

The results of field tests conducted during the winter heating season on the thermal performance of the building envelopes of eight office buildings situated in various climatic regions are presented. The exterior envelopes of these buildings are masonry and metal-panel-faced construction of different designs. In situ measurements of heat flow through the envelopes and of air temperatures were made using heat flux transducers, portable calorimeters, and thermistors. The influences of the length of measurement period and the time lag between the air temperature difference across the envelope and the heat flow on the determination of the thermal resistance are described. The calorimeter measurement generally gives lower wall thermal resistance values than the heat flux transducer because of the additional heat flow through highly conductive framing members. Heat flow and air temperature measurements carried out over a period of 48 h and longer are found to provide satisfactory thermal resistance data. The measurements' accuracy can be improved through correction of the data for time lag. The masonry and metal-panel-faced exterior walls of these buildings tested have widely varying thermal resistances, ranging from approximately 0.5 to 5.6 m2 · K/W (3 to 32 ft2·h·°F/Btu). The measured values deviated from the predicted values by an average of 22%, and in one case by as much as 71%.
Air Movements and the Thermal Performance of the Building Envelope
Authors: Bankvall CG
Published: December 2008

Air movements will influence the thermal performance of the building envelope; to what degree will depend on the pressure situation in and around the structure, the permeability of the different materials, and the airtightness of joints between materials and building elements. In a multilayer structure with a high thermal resistance, different parts have different functions in order to protect against unwanted air flow and ensure airtightness.

Wind protection will give a degree of safety against air flow in the insulation, especially in situations involving large wind loads. Certain areas of the structure may be more sensitive and have a higher need for wind protection than others. In a similar way, the building envelope will be sensitive to air infiltration. The inside—that is, the vapor barrier, inside board, and joints—will greatly influence the air flow and the heat losses from the envelope.

Both types of increased heat losses from the building envelope (that due to air flow along the insulation and that due to air infiltration) will most influence envelopes with high thermal resistance. This type of envelope is typical of today's design in Scandinavia, and the results and discussions are related to this.
Measured Insulation Improvement Potential for Ten U.S. Army Buildings
Authors: Flanders SN
Published: December 2008

As-built drawings and handbook calculations of R values are often inadequate bases for investment decisions regarding improved insulation of U.S. Army buildings. Reported field and laboratory experience indicates that a technique employing surface-mounted heat flux sensors (HFSs) in conjunction with infrared thermography (IRT) can yield reliable estimates of R values. This technique employs IRT to position HFSs and thermocouples at representative locations on walls and roofs or attics to acquire heat flow and temperature data for estimating R values. This paper reports on the application of this technique at Ft. Carson, Colorado, and Ft. Richardson, Alaska, to eight family housing units, a temporary office building, and a barracks.

Infrared thermography of these buildings detected few thermal anomalies, but measurement of several walls with HFSs and thermocouples (typically at six locations spaced vertically on each wall) revealed significant variation in estimated R values; this variation is attributable to convection, even within fully insulated walls. This is significant for proper placement of sensors and indicates that installed fibrous insulation can lack the ability to quell convection. The insulating ability of walls containing poorly installed mineral fiber batt insulation was much worse than would be indicated by the design handbook values. Some attic insulation performed exactly as expected; some was at least 40% worse than expected.

Plotted curves using the life-cycle cost assumptions required by the U.S. Army's Energy Conservation Investment Program show the budget necessary for each level of insulation improvement to break even over a 15-year economic life. At Ft. Carson, filling empty stud cavities in brick veneer construction to an overall R value of 13 would warrant an investment of about $17.6 per square metre ($1.63 per square foot). A contractor estimates that the actual cost would be only $4.5 per square metre ($0.42 per square foot). At Ft. Richardson an R-20 level of insulation would justify an expenditure of between $12.9 and $30.1 per square metre ($1.20 and $2.80 per square foot) of wall on the wood frame buildings that were measured. Attic spaces at both installations were heavily insulated and had much less potential for improvement than walls.

The IRT/HFS measurement technique is most useful on poorly insulated buildings, where the inaccuracy of information about the initial insulating level has the greatest impact on the allowable budget for additional insulation.
A Detailed Verification Procedure for a Guarded Hot Box
Authors: Guy AG , Nixon JA
Published: December 2008

A verification procedure carried out for a particular guarded hot box facility is described. This relied on measurement of a uniform test specimen of known well-defined properties, these properties having been measured on an accredited guarded hot plate. An analysis of the various energy flows in the box is given, together with procedures for application of various correction measures required. These included a common zeroing of any out-of-balance flux through the metering box walls with that in the specimen across the metering box periphery. The effects of specimen mean temperature were included, and specimen thermal conductances and metering box thermal properties were determined using a linear regression approach. Resulting conductances were in good agreement with those obtained from the hot plate measurements.
Heat Transfer Characteristics of a Masonry Cavity Wall
Authors: Van Geem MG
Published: December 2008

Heat transfer characteristics of building elements must be known to evaluate energy losses through a building envelope. Laboratory tests of walls under dynamic temperature conditions provide data that can be used to determine thermal properties. Dynamic testing is particularly important for massive envelope components that store as well as transmit heat.

A block-brick cavity wall was tested in the calibrated hot box facility at the Construction Technology Laboratories, a division of the Portland Cement Association. The wall consisted of 100-mm (4-in.) clay brick on the exterior face, a 70-mm (24-in.) cavity, 150-mm (6-in.) concrete block, and 3 mm (⅛ in.) of plaster on the interior face. Metal rectangular ties were used for tying brick and block wythes.

Laboratory tests were performed on the wall with and without expanded perlite fill in the cavity. The wall was subjected to steady-state, transient, and periodically varying temperature conditions. Steady-state results are used to define heat transmission coefficients, such as U and R values. Data obtained during transient and periodic temperature variations are used to define dynamic thermal response of the wall. Dynamic response includes heat storage capacity as well as heat transmission characteristics of the wall assembly. Test data are also used to determine the effects of perlite insulation in the cavity.

The cavity wall construction is similar to that of a test building monitored by the National Bureau of Standards (NBS) in Gaithersburg, Maryland. Two of the dynamic temperature cycles applied to the wall during laboratory tests were derived from actual wall surface temperatures at the NBS test building. Heat flow meter data from the test building are compared with calibrated hot box test results.

Laboratory test results provide a data base for evaluation of building envelope performance where cavity walls are used. The results also provide information on the effectiveness of expanded perlite as a cavity-fill material.
Field Study on Moisture Problems in Exterior Walls of a Masonry Housing Development on the Coast of the Gulf of Mexico
Authors: Trechsel HR , Achenbach PR , Conklin S
Published: December 2008

Like many other buildings in the warm and humid climate of the Gulf Coast, family quarters at the Pensacola Naval Air Station, Florida, have experienced serious moisture and mildew problems. Earlier attempts to correct the situation have not been totally successful.

Following an exploratory study in the spring of 1982, measurements of temperatures, relative humidities, air infiltration, and water leakage were taken, and other tests were conducted on several dwelling units over the period from September 1982 to May 1983. During the same period, two surveys of individual houses were conducted to determine the extent of the moisture problem and to document occupant practices that might influence or aggravate the problems.

This report summarizes the individual test and survey results. The results indicate that rainwater penetration through cracks in the masonry walls and at windows is a major source of the moisture observed in the gypsum board and the thermal insulation. Inadequate ventilation, particularly within the bedrooms, and possibly capillary rise of moisture from the foundations may also have contributed to the moisture problem. The report discusses these conclusions and lists possible remedial measures.
Condensation Potential in Wood-Frame Walls
Authors: Sherwood GE
Published: December 2008

As a result of steadily rising energy costs, construction practice for light-frame wood structures has changed over the past few years. The use of 152-mm (6-in.)-thick walls and application of high-R-value (thermal resistance value), low-permeance sheathings to 102-mm (4-in.) walls has caused concern for the moisture patterns that may occur in walls. To observe actual moisture patterns and the potential for condensation, test structures were constructed near Madison, Wisconsin, and near Gulfport, Mississippi, for exposure of eight types of insulated wall panels at controlled indoor conditions and typical outdoor weather conditions. Panels were instrumented with moisture sensors and tested without (Phase 1) and with (Phase 2) penetrations (electrical outlets) in the indoor surface.

Continuous inside vapor retarders effectively prevented cold weather condensation in all the panels. Installation of an electrical outlet changed moisture patterns in both the cold winter climate and the hot, humid summer climate. Although condensation occurred for limited time periods in some panels at both test sites, the moisture content of framing did not rise to critical levels.

This paper should be useful to building designers, builders, and building code officials.
Wetting of Polystyrene and Urethane Roof Insulations in the Laboratory and on a Protected Membrane Roof
Authors: Tobiasson W , Greatorex A , Van Pelt D
Published: December 2008

When subjected to a sustained temperature gradient in the presence of moisture in laboratory wetting tests, urethane and expanded polystyrene roof insulations accumulate enough moisture to reduce their insulating ability significantly. Extruded polystyrene is quite resistant to moisture in such tests. But the vapor drive is not as great in actual roofs, and it may reverse direction, thereby seasonally drying the insulation. To determine how well the laboratory tests could predict the wetting rate of insulation in actual protected membrane roofs, extruded and expanded polystyrene and urethane insulations were installed in a protected membrane roof in Hanover, New Hampshire. After three years of exposure, little moisture had accumulated in the extruded polystyrene, and it still retained essentially all of its initial insulating ability. Moisture progressively accumulated in 16-kg/m3 (1-lb/ft3) and 30-kg/m3 (1.9-lb/ft3) expanded polystyrene insulations, and at the end of the test they retained only about 30 and 40% of their initial thermal resistance, respectively. The urethane accumulated enough moisture to reduce its insulating ability to about 30% of its dry value. The laboratory tests provided a valuable indication of the potential long-term moisture gain of these insulations when installed in protected membrane roofs in cold regions.
Anomalous Behavior of Water Vapor Retarders Applied to Spray-Applied Polyurethane Foam Insulation on Low-Temperature Outdoor Storage Tanks
Authors: Batdorf V
Published: December 2008

The diffusion of water vapor through permeable retarders applied over thermal insulation in low-temperature service is a function of vapor pressure differentials. For permeable insulation materials of a fibrous nature, with an installed vapor retarder on the warm side, the annual intake of water by vapor diffusion is readily calculated.

It has been observed that for sprayed-on polyurethane foam insulation, the actual intake is substantially less than calculated. Field data from eight and eleven-year-old installations of spray-applied polyurethane foam, covered with vapor-retardant mastic on large storage tanks containing agricultural liquid ammonia held at −33°C (−28°F), show that the calculated level of water intake was not attained and that the insulation material continues to perform without significant change in thermal transmission.

The author hypothesizes that the cellular nature of the insulation restricts and changes the diffusion mechanism and that the absence of free air spaces within the insulation attenuates moisture diffusion paths.
Thickness and Density of Loose-Fill Insulations After Installation in Residential Attics
Authors: McElroy DL , Yarbrough DW , Graves RS
Published: December 2008

Limited information exists on the extent of settling of loose-fill attic insulations as a function of time after installation. This study reports thickness and density measurements in attics immediately after installation and periodically for two years following. Installations of fiberglass A, rock wool, fiberglass B, perlite, and cellulose in 44 attics in Ohio, Washington, and Tennessee were examined periodically.

The thickness, t, at fixed locations was measured using probes, rulers attached to ceiling joists, and polystyrene floats guided by rulers. The density, ρ, was determined using a cylindrical cutter to define a specimen of known volume that was weighed on site. The observed values of t and ρ were correlated with time after installation, and manufacturers' descriptions of products including thermal resistance expectations.

As part of the analysis of cellulosic insulation behavior, a series of laboratory tests of the blower-cyclone-shaker technique were conducted, and the findings from these tests are reported.
A Calorimeter for Determining Heat Transmission Characteristics of Windows
Authors: Bowen RP , Solvason KR
Published: December 2008

Heat loss through windows is receiving an increasing amount of attention from consumers, manufacturers, and building designers. The technology is changing and should lead to substantial improvements in thermal performance. To assist in the evaluation of existing as well as new products, the Division of Building Research, National Research Council of Canada (DBR/NRCC), has designed and built a new calorimeter for use in their Environmental Test Facility.

This paper presents an approach for determining the heat transmission characteristics of windows using the radiative and convective components of heat transfer from the calorimeter to the specimen surface. Through calibration tests using materials of known conductance, expressions for the radiation exchange between the calorimeter surfaces and the specimen and the calorimeter air to the specimen can be determined. These expressions are then used when testing a window to calculate an equivalent surface temperature for the window. This approach is necessary because of the difficulty in determining an average surface temperature on glass.

Although the approach can be used with conventional calorimeter designs, uncertainties are introduced because of the changing calorimeter characteristics for different sizes of specimens. To reduce the uncertainties, the new calorimeter was designed to have a constant convection coefficient and uniform temperature radiation field. The calibration program is discussed, and some preliminary results are given.
Case Histories of Moisture Monitoring in Residential Walls
Authors: Kane R , Titley G
Published: December 2008

There is an unjustified concern within the building industry that the use of an exterior low water vapor permeance foam sheathing design allows an accumulation of moisture between the vapor barrier and the exterior sheathing.

In this study the authors measured the moisture content in the wood studs of seven occupied homes, in four Canadian cities, with a low water vapor permeance sheathing (extruded polystyrene), with or without a noninsulating sheathing, such as plywood, fiberboard, or chipboard, used on the exterior of the house. The degree days ranged from 4068 to 5920°C, and the relative humidity ranged from 71 to 83.5%. In all cases the actual moisture content of the studs was measured with Delmhorst moisture elements and then read with Delmhorst moisture meters. The results show a similarity in moisture concentration patterns regardless of the exterior sheathing installed. The effects of construction practices and local relative humidities are discussed.

The practical usefulness of actual moisture studies of real homes, done in a variety of climates, will be most interesting to today's architects and builders.
A Method to Predict the Hour-by-Hour Humidity Ratio of Attic Air
Authors: Cleary P , Sonderegger R
Published: December 2008

Long-term measurements of attic wood moisture content have shown that at least 50 kg of water may be stored in roof sheathing members over the course of the winter, to be released in the spring. Overlaid on this seasonal cycle is a daily variation driven by temperature changes in the attic. A dynamic model is required to predict the resulting attic air humidity ratio. Hourly moisture flows in a typical attic—from ventilation and from the wood—are examined, and a simple first-principles dynamic mathematical model to relate them is developed. The model predicts the hour-by-hour attic air humidity ratio. The results are compared with measured data. The implications for attic ventilation rates at different levels of attic insulation are discussed.
Human Protection from Burns by Heated Surfaces—The Problem and Solution
Authors: Mumaw JR
Published: December 2008

Insulation in some form has been used in the home for centuries to protect the occupants against extremes of heat and cold. With the Industrial Revolution, insulation was applied to industrial processes to conserve energy and, more important, to protect the process products during manufacture. As technology expanded, bringing more complex processes, higher temperatures, and more worker exposure situations, an increased awareness of the need for worker safety led to the use of insulation for personnel protection. Unfortunately, it was not until after World War II that adequate medical data were available to aid in the definition of a “safe” heated surface. To this day, the definition of “safe conditions” for heated surfaces varies widely among consultants, appliance manufacturers, insulation producers, and regulatory agencies. In 1983, ASTM Committee C-16 on Thermal Insulation began work toward developing standards to resolve these issues. This paper outlines the approach taken by the working task groups to establish (1) a standard definition of the human burn mechanism for heated surfaces and (2) the tools required to determine if a surface presents a hazard.
Building Component Test Development Using Module Simulators
Authors: Roberts CC
Published: December 2008

In certain instances consensus standard test methods may not model building responses to environmental influences. Researchers in the past have utilized module simulators, which are model buildings for comparing the effects of specific building components and interactions between several building components. Examples of module tests are presented. A draft ASTM comparative module test method is also presented; this test method may be useful both in analyzing complex phenomena not addressed by present consensus standard test methods and as a basis for the development of a consensus standard test.
Relationship Between the Rheological Properties of Asphalt and the Rheological Properties of Mixtures and Pavements
Authors: Davis RL
Published: December 2008

The central tenet of this paper is that a proper level of bearing capacity is essential to good asphalt pavement performance. Methods for designing pavements with increased bearing capacity and methods for measuring this property are recommended. Since the bearing capacity of asphalt pavements is seldom determined, the fact is often overlooked that many pavement failures that are attributed to stripping, inferior asphalt quality, and inferior stone quality are actually structural failures due to inadequate bearing capacity. Increased truck tire pressures menace many pavements which were designed to traditional standards but which have bearing capacities too low to cope with the higher stresses. The only practical way to save these pavements from premature failure is to lower the stresses or tire pressures on them during hot weather.

The complexity of the rheology of asphalt and asphalt pavements and the poor precision of test methods used to measure these properties require that the conditions of test be carefully matched to road conditions in order that the results be meaningful.

The use of aggregate graded to a high volume concentration and with a top size two-thirds the thickness of the pavement dramatically increases bearing capacity.

Low-viscosity asphalt and air voids of less than 3% greatly increase the durability of asphalt pavements.
Basic Rheology and Rheological Concepts Established by H. E. Schweyer
Authors: Tia M , Ruth BE
Published: December 2008

The flow properties of asphalts are usually characterized as Newtonian, pseudoplastic, dilatant, Bingham plastic, and thixotropic. Asphalts always exhibit some degree of elasticity. Therefore, even asphalts with Newtonian flow properties cannot be truly classified as Newtonian materials. In general, we can consider these flow categories to be a function of the shear susceptibility (complex flow) of the material. Most paving grade asphalts will exhibit Newtonian-like (C = 1.0) flow properties at or near conventional mix temperatures. At high shear rates the material may develop pronounced dilatant behavior (C > 1.0). However, at low temperature (<25°C) we often observe a greater degree of pseudoplastic (C < 1.0) behavior. The use of a fixed or specified shear rate for computation of asphalt viscosities at lower temperatures is often misleading and may result in erroneous interpretation of test results. The advantages of using constant power viscosity (ηi) is discussed in conjunction with viscosity-temperature regression analyses for evaluation of temperature susceptibility. This paper presents a thorough and concise overview of rheological types with emphasis on the need for rheological measurements throughout a range in temperature. The presentation discusses measurement methods and relies heavily on procedures purported by H. E. Schweyer as being excellent for the characterization of paving and roofing asphalts. The theoretical basis of the Schweyer constant stress rheometer is fully presented. The operation of the rheometer and procedure for analysis of data are described and illustrated by an example. The application of low-temperature viscosity test results using the Schweyer rheometer is also shown by an example.
Improved Rheological Properties of Polymer-Modified Asphalts
Authors: Muncy HW , King GN , Prudhomme JB
Published: December 2008

Polymer modification dramatically changes the rheological properties and therefore the performance of asphalt cement. This study discusses conventional and new methods of specification testing for the polymeric elastic and tensile properties. Five asphalts were tested before and after polymer modification for penetration, viscosity, low temperature ductility, pen-vis numbers (PVN), and aging indices. Tensile strength, force ductility, toughness and tenacity, dropping ball, creep response, elastic recovery by ductilometer, torsional recovery, sliding plate rheometry, Dekker elastic recovery, and temperature susceptibility test methods are also examined. It is concluded that current asphalt cement specifications should be supplemented with tests for tensile strength and elastic recovery if the relative performance properties of polymerized asphalt cements are to be compared.
Rheological Properties of Sulfur Asphalt Binders with Fillers Determined by the Sliding Plate Rheometer
Authors: Akili W , Courval GJ
Published: December 2008

Sulfur continues to be favored as a potential asphalt extender in road paving operations. Over the past decade, developments in the field of sulfur/asphalts (S/A) have proceeded at a rapid pace, leading to products and technologies that are currently at the early commercialization stage. In this study, the properties of selected S/A binders mixed with three commonly used mineral fillers (cement, hydrated lime, and crushed limestone fines) were determined using the sliding plate rheometer. Variables have included loading time, temperature, and S/A weight ratio. The results indicate that sulfur has a much greater influence on measured properties such as viscosity and stiffness than mineral fillers alone. S/A binders, with hydrated lime filler, have exhibited higher viscosity and stiffness than binders prepared with cement or limestone fines. The rheometer data, coupled with photomicrographs, support the notion that the morphology of S/A binders with fillers is very different from that of S/A binders alone in terms of potential voids, sulfur recrystallization, and the size of crystal platelets.
Designation, Identification, and Characterization of Metals and Alloys
Authors: Westbrook JH
Published: December 2008

In contrast to the situation with polymeric and ceramic materials, alpha-numeric designation systems are relatively well established and well known for metals and alloys. Unfortunately, since such designations are mostly based on composition alone and differ between alloy groups, major problems still occur in building computer files for an information system of broad scope in materials and properties. This paper reviews existing systems of designation for metals and alloys and outlines the approach taken for characterization of materials in the MIST demonstration program being built for the National Materials Property Data Network.

Designation systems for metallic materials have been formulated by the trade associations (for example, Aluminum Association [AA], Copper Development Association [CDA], and the American Iron and Steel Institute [AISI]), by professional societies (for example, ASTM), by user groups (for example, Military and Federal), and by private companies (both users and producers). Naturally this has led to a chaotic situation with many ambiguities and uncertainties. A big step forward was taken by ASTM-Society of Automotive Engineers (SAE) who established a Unified Numbering System (UNS), which provided a logical and unambiguous code for thousands of commercially important metallic materials. Unfortunately, not all significant alloys are included; the coding relates to composition alone; and the scheme has not been endorsed outside the United States by such bodies as the International Standards Organization (ISO), or the European Standards Association.

Since in general properties are not defined by composition alone further characterization must be provided. Among the features that must be noted are form, size, method of synthesis, post-processing treatments, applications, and so forth. Illustrations of the incorporation of all these descriptors are taken from the metadata structure built for the Materials Information for Science and Technology (MIST) system.
VAMAS Activities on Materials Data Banks
Authors: Reynard KW
Published: December 2008

The Versailles Project for Advanced Materials and Standards (VAMAS) Task Group on Materials Data Banks has surveyed the VAMAS countries to identify areas where standards are needed to build and distribute factual materials data banks. It presented its report to the Steering Committee in May 1987.

This paper reviews the findings and recommendations of the Task Group. These have a particular relevance to the work of ASTM Committee E-49, as the input to the report related all the recommendations to the likely end result of standards for materials data and other information being stored and accessed by computer.

Many of the topics have been debated in the Workshops of Fairfield Glade, Petten, and Schluchsee in recent years. The recommendations take account of the work that has been done in several countries following these discussions. It is therefore no surprise that topics such as systems for the designation of materials, terminology, multilingual dictionaries and definitions, computerized directories for testing standards and the equivalence of materials, and methods of linking data bases and their access are given a high priority. What is different is the direct relationship between the recommendations and those producing standards, codes, and guidelines.
Materials Data Activities in China
Authors: Lu Y , Fan S
Published: December 2008

Current materials data activities in China are described. Some features are summarized and some applications are listed. A variety of materials data bases have been introduced. Some of them are described in detail. In addition, the organization of materials data bases in China is reviewed and its future predicted.
Information Systems Design for Material Properties Data
Authors: McCarthy JL
Published: December 2008

Material properties data present numerous challenges that current data base management technology does not address. Major problems include data complexity, naming conventions, measurement units, summary levels of abstraction, and data sparseness. Networks and gateways to multiple material information systems compound these challenges and add others.

Experience from projects such as the Materials Information for Science and Technology (MIST) system prototype suggests several general approaches that address these problems, including modular system architecture; a three-tiered approach to naming materials, properties, and variables; an active data thesaurus; material and variable class hierarchies; structured representation of tables and graphs; and existence tables to indicate data availability by the cross product of materials, properties, and independent variables for any given data base. It also suggests that we need to go beyond the simple relational model to solve our problems and implement solutions.
Data Base R&D for Unified Life Cycle Engineering
Authors: Burte HM , Harmsworth CL
Published: December 2008

Unified life cycle engineering should encompass designing for performance, producibility, and supportability in an interactive mode. It will combine computer aided design (CAD) and computer aided manufacturing (CAM) with supportability concerns such as inspection, corrosion protection, repair, and replacement. This new engineering approach will deal with these parameters in the design process from a total life cycle standpoint.

The development of such an approach will require the integration of existing data bases and the development of new information sources. Today's data bases are not sufficient in scope nor do they meet the statistical requirements for such a concept. No system automatically prompts the user with the warning notes and “do's and don't's” that must be considered to prevent an unintentioned misuse of materials property data. Rapidly locating and accessing the needed range of diverse information and making it available for intelligent, interactive use by the designer presents a significant challenge.
Socioeconomic Barriers in Computerizing Materials Data
Authors: Rumble JR
Published: December 2008

While the computer technology, both hardware and software, exists to allow easy and comprehensive access to computerized data on engineering materials, only a few data bases are publicly available today. The reason for this is a set of barriers based on socioeconomic factors that are only partly recognized. In this paper, the use of materials data is examined to identify some of these socioeconomic barriers. They primarily arise from three factors: complex usage patterns, a relatively new computer audience combined with an exploding computer technology, and a lack of understanding of the positive impact of computerized materials data. Ways to overcome these barriers are suggested.
Generation and Use of Composite Material Data Bases
Authors: Ranger K
Published: December 2008

The use of composite material data bases in the structural design process is important due to the great number of material systems that are currently available. In preliminary and final design, it is efficient to have computer programs that use data bases containing fiber, matrix, ply, and laminate information. Definitions and methods of generation (estimation techniques and test methods) for these data bases are included. The AS1/3501-5 graphite/epoxy material system is used in the examples. This paper is intended as a guide for implementation of a composite material data base system for a design group.
Welding Information Systems
Authors: Jones JE , Vanderveldt HH
Published: December 2008

This paper presents recent developments in Welding Information Systems at the American Welding Institute (AWI). First, it covers the traditional data and knowledge representation and use of welding technology. Then it presents the use of advanced computer technology to rapidly retrieve and use of new welding technology. Specifically, the paper discusses applications developed by AWI in the use of 4GL data-base systems for welding data; the use of knowledge representation techniques in the development of expert systems for welding application; and the use of neural network simulators for associative memory storage and retrieval of welding-related image data. The paper presents an overview of the WIN™ system, a welding engineering workstation developed by AWI.
A New Pair of Eyes II. Looking at Dispersants from a Different Point of View
Authors: Katz WB
Published: December 2008

Those concerned with managing oil spills have been struggling for the past 15 to 20 years to improve the application and effectiveness of dispersants. Progress has been slow and uneven, especially in the United States where the attitude of regulatory agencies has been to downplay the use of dispersants. This paper takes a serious (occasionally irreverent) approach to the problem of dispersing oil, using some different viewpoints than have been used in the past.
Applications of Supercritical Fluid Chromatography-Mass Spectrometry in the Analysis of Fossil Fuels
Authors: Chess EK , Kalinoski HT , Wright BW , Udseth HR , Smith RD
Published: December 2008

Supercritical fluid chromatography-mass spectrometry (SFC-MS) and related techniques have been applied to the chemical characterization of a variety of fossil fuels, including diesel fuels, diesel fuel sediments, and petroleum- and coal-derived liquids and solids. Supercritical fluid chromatography can provide either high resolution or extremely rapid separation of complex fuel-derived mixtures. Insoluble sediments from marine diesel fuels can be extracted with polar supercritical fluids and the extracts directly introduced to a mass spectrometer for on-line characterization. Chemical class separations and mass spectrometric analysis of coal-derived liquids can be accomplished by utilizing high-performance liquid chromatography columns and a specially designed interface to the mass spectrometer. The development of polar supercritical fluids and Chromatographic columns for use with the polar fluids and the development (in addition to refinement) of the SFC-MS interfaces and capillary flow restrictors have been responsible for the successful application of SFC-MS and related techniques to the analysis of fossil-fuel-related materials.
A Comparison of the Methods of Medium Resolution Selected Ion Recording and Multiple Reaction Monitoring When Applied to the Analysis of Steranes and Triterpenes in Crude Oil Extracts
Authors: Harriman GE , Owen R , Parr VC , Weir O , Wood D
Published: December 2008

Oil correlation studies and assessments of the environment of deposition of source rocks and of the maturation, migration, and biodegradation of crude oils are commonly based upon the distribution of “biological marker” compounds within the oil or source rock extract. The measurement of these compounds involves the use of combined capillary column gas chromatography with mass spectrometry. However, the compounds are usually present at low levels and so selected ion recording techniques are preferred. Comparisons are made of two methods for increasing the selectivity of the mass spectrometer beyond that available when using nominal mass resolution, such as that available with quadrupole instruments. These methods are, increasing the mass spectrometer resolving power to, say 2 to 3000, and secondly to monitor fragments formed in the first field free region of a double-focusing instrument. The second method generally yields data that are easier to interpret and are less confused by interferences. Moreover, the sensitivity is adequate to obtain results using whole oils and total source rock extracts without prior sample cleanup and concentration.