bluuebunny/crossref_metadata_2025_split huggingface dataset:
Growth of Short Cracks During High Strain Fatigue and Thermal Cycling
Authors: Skelton RP 
Published: March 2009

Research in high-temperature fatigue usually concerns either crack initiation and endurance of smooth specimens in high strain fatigue (HSF) or the growth of long cracks in the nominally elastic regime described by linear elastic fracture mechanics. This review shows that the relatively unfamiliar growth rates in HSF can be linked to those in stress-intensity controlled growth, and so can be used satisfactorily for predicting component failure. Either a strain-based intensity parameter or a J-integral method may be used, and several examples are given. Integrated HSF growth rates are also shown to be consistent with smooth specimen endurance from (1) striation measurements, (2) direct measurement, and (3) the predictions of the shear decohesion model.Empirical HSF growth relations are summarized and the effects of temperature, environment, tension dwells, and microstructural damage are assessed in several alloys. The greatest correction that has to be made to the experimental and theoretical growth relations arises from the accelerating effects of creep during dwell.
The Concept of Uniform Scatter Bands for Analyzing S-N Curves of Unnotched and Notched Specimens in Structural Steel
Authors: Haibach E , Matschke C 
Published: March 2009

From an extensive test program, 53 S-N curves, established for alternating, zero-tension, or fluctuating tension constant amplitude loading conditions, are obtained for unnotched and three types of centrally notched flat specimens of structural steel Ck 45 (SAE 1045) and 42 CrMo 4 (SAE 4140). These S-N curves are intended to improve existing fatigue design data for application of the two steels tested in cases of finite life design.
The comparative evaluation of the test series reveals the possibility of describing the test results in log S-logN diagrams in terms of uniform scatter bands when distinguishing between the unnotched specimens, the notched specimens in the annealed condition, and the notched specimens in the quenched and tempered condition. These experimental findings are compared with an analytical analysis based on the local stress-strain approach using Neuber's rule. This analysis explains that the derived concept of uniform scatter bands is in accordance with our present understanding of the fatigue behavior of notched elements. Moreover, it allows the agreement of the analytical model and the actual material behavior to be critically examined. In conclusion the paper outlines the link between the nominal stress concept and the local stress-strain approach for deriving engineering fatigue design data.
Aggregate-Related Applications for Residues from Fluidized Bed Combustion Boilers
Authors: Collins RJ 
Published: March 2009

Continuing development of atmospheric fluidized bed (AFB) combustion systems offers great potential for producing energy from low quality coals and other combustible materials in an environmentally acceptable manner. The process involves burning the crushed coal in a bed of limestone or dolomite that has been fluidized by jets of hot air. The resultant by-products are a dry, sand-size spent bed residue and a relatively high carbon fly ash. Potential aggregate-related applications for these by-products, and in particular the spent bed residue, are discussed.
This paper is a further progress report for a research program sponsored by the U.S. Department of Energy to evaluate potential commercial applications for fluidized bed combustion wastes. Included in this paper are laboratory data related to a number of different AFB by-product sources; a summary of separation efficiencies of several beneficiation techniques; and supporting data related to three of the most promising applications for spent bed residues. These applications are stabilized road base compositions, masonry block, and synthetic aggregate. Data pertaining to laboratory studies and small-scale field demonstrations for each of these applications is presented and discussed.
Resource Conservation by Use of Iron and Steel Slags
Authors: Lewis DW 
Published: March 2009

Use of iron and steel slags as construction materials is believed to be the oldest and best developed “resource recovery” operation in the world. Iron blast-furnace slag use in the United States began more than 100 years ago with current use about equal to production. Steelmaking slags were largely wasted prior to World War II but are now used extensively in flexible pavement construction and railroad ballast. The 1979 Bureau of Mines data show use of nearly 36 million tons (32.5 × 106 Mg) of slag in commercial applications, replacing a similar amount of virgin materials.
Supplies of blast-furnace and steel slags are expected to increase by only a small amount during the remainder of this century. Use patterns will undergo marked changes, greatly increasing energy conservation and continuing conservation of virgin materials. Large amounts of blast-furnace slag will be processed for use as a cementitious material, saving both the virgin raw materials that would be used to produce a similar tonnage of portland cement and the huge amounts of energy used in cement kiln operation. Increasing recognition of the skid resistant characteristics of steelmaking slags will result in greater usage in asphalt concrete surface courses.
These changes in use patterns will decrease the amounts of slag available for use in base course and embankment construction. In many areas, it will be possible to use lower quality natural aggregates, recycled construction materials, or suitably processed wastes in these applications, thus further extending the supply of high quality virgin aggregates.
Single-Ply Synthetic Rubber Roofing Membranes
Authors: Doherty FW , Shloss AL 
Published: March 2009

Desirable performance characteristics common to all roof installations are the ability to accommodate movement and to remain functional at ambient temperatures while resisting the extremes of the elements, particularly the ravages of ultraviolet light, air pollutants, and water. Synthetic rubbers possess desirable performance attributes for single-ply roofing membranes, particularly those sheets based on properly formulated compositions of polychloroprene, chlorosulfonated polyethylene and ethylene/propylene/diene terpolymer. The latter elastomers have demonstrated long-term resistance to weather and water in a variety of other applications to a degree that has commended their consideration as sheet rubber roofing membranes throughout the world. Such membranes have satisfactorily served as integral parts of successfully functioning roofing systems for 15 to 20 years.
The fundamental characteristics of these synthetic rubbers as single-ply rubber roofing membranes are examined by reviewing: (1) architectural and design considerations, (2) installation parameters, (3) performance and durability, (4) synthetic rubber polymers, (5) role of rubber products manufacturer and contractor/installer, and (6) industry acceptance.
Atmospheric Corrosion of Weathering Steels
Authors: Knotková-Čermáková D , Vlčková J , Honzák J 
Published: March 2009

A general research program to study the corrosion behavior of weathering steels is being completed by the State Research Institute for Materials Protection. Three stages of research are discussed:
1. a description of the corrosion characteristics of these materials.
2. the corrosion behavior of weathering steels in structural service, and
3. the evaluation of the applicability of weathering steels for typical real structures.
The results of this program were used to formulate the corrosion section of the specification: Technical Direction for Application of Weathering Steels.
A comparison of the cost of construction using conventional paint coatings on steel versus the use of weathering steel is provided, including the protection and operation of construction.
Effect of 1 Percent Copper Addition on Atmospheric Corrosion of Rolled Zinc After 20 Years' Exposure
Authors: Showak W , Dunbar SR 
Published: March 2009

The atmospheric corrosion characteristics of a commercial rolled zinc alloy containing 1 percent copper and an unalloyed grade have been evaluated after 20 years' exposure under ASTM Committee B-3 (now G 01.04.04) 1957 test program on atmospheric corrosion of nonferrous metals. Corrosion damage was assessed by measurement of loss in weight, loss in mechanical properties, and depth of pitting. The 20-year corrosion rates are analyzed with respect to previous 2- and 7-year results. Comparisons are also made with the behavior of three unalloyed grades of rolled zinc investigated in the 20-year 1931 program by Committee B-3 using weight loss and tension test methods.
Weight loss method appears to be the most reliable way of determining the corrosion rates of zinc. Corrosion rates found for zinc in the 1931 and 1957 test programs are in good agreement. The corrosion rate of zinc is not significantly affected by variations in compositions investigated.
Local galvanic action is probably responsible for the pitting which occurs in the copper-containing zinc alloy. Pitting is most severe in the marine atmosphere in direct contact with salt spray. The pit-depth/total-penetration ratio tends to decrease with increasing total penetration. The net change in tensile strength after 20 years' exposure at all four test sites is equal to or less than that expected due to weight loss. Tensile elongation is found to be more sensitive to corrosion effects than tensile strength, although both alloys still possess considerable ductility after 20 years.
A better way of compensating for aging in zinc is needed if tension test results are to be useful in evaluating corrosion damage.
Chironomidae Toxicity Tests—Biological Background and Procedures
Authors: Anderson RL 
Published: March 2009

Toxicity tests must be based on an understanding of the test animal's life cycle. The first section of this report describes the biological information needed to develop toxicity test procedures. The second section describes three categories of toxicity test systems—short-exposure, partial life-cycle, and life-cycle exposures.
Each researcher has developed a procedure to solve a particular problem. Therefore, it is impossible to provide specific recommendations for a general toxicity test. In practice, anyone using chironomids should establish a clear experimental objective and then select the test species. The required biological information and test procedure can then be obtained from the literature or developed by experimentation.
Failure During Construction and Subsequent Rehabilitation and Performance of a Dynamically Cast-in-Place Concrete Pile Foundation
Authors: Clark JI 
Published: March 2009

During construction of a dynamically cast-in-place concrete pile foundation for a heavily loaded library tower at the University of Calgary, extensive pile heave was recorded. Consultants were engaged to assess the effect of pile heave on the pile capacity. A down-hole sonic tool was used to assess several piles where damage was suspected, and the results indicated severe damage to the pile shafts. Load tests confirmed the results when piles failed at a fraction of the required load. Further assessment led to the conclusion that 200 of the total of 292 piles were not capable of supporting the design load.
The contractor elected to rehabilitate the damaged piles by adopting a pressure grouting technique recommended by the consultants. Load tests confirmed the viability of the grouting method, and it was implemented for all damaged piles. During the rehabilitation, extensive fracturing of the soil was revealed at various depths over the entire building site. The piles were successfully rehabilitated, and the structure was instrumented to record settlement during and after construction. Settlement records have been maintained for seven years since construction.
Load Testing of Instrumented 225-Foot-Long Prestressed Concrete Piles
Authors: Lacy HS 
Published: March 2009

Piles driven through 62 to 77 m (200 to 250 ft) of low-strength clay penetrated up to 23 m (75 ft) into compact fine sand with little increase in driving resistance. At other locations, the piles met refusal after only about 1 m (3.3 ft) of penetration into the sand. Borings indicated a consistently compact bearing stratum. This test program was developed to establish whether piles driven to very low driving resistances at moderate penetration into the lower compact sands would support the 91-Mg (100-ton) design load. The overlying clays provided no permanent pile support, as in some areas they are underconsolidated as a result of site filling.
The test program included casting eight electric strain gages and a 7.6-cm (3-in.) diameter hole in 36-cm (14-in.) square prestressed concrete piles. The piles were driven in three sections to low driving resistances with a continuous record of driving stresses. Anchors were installed in the center hole, with rods extending to the surface. The top of the piles were loaded in increments to 3½ times the design load to overcome the loss of load into the thick clay layer. A procedure of performing the load test a short time after the pile was driven and cyclic loading after reaching maximum test load was used to increase the load reaching the lower compact sand stratum. Full-scale laboratory load tests were preformed on a section of pile to establish the variation in elastic modulus to permit accurate estimates of pile load at various depths.
The pile load tests demonstrated that the deep compact sand layer was capable of supporting the design loads, even though penetration was terminated at low driving resistances. Substantial portions of the load during the short-term tests were resisted by adhesion in the thick clay layer. The amount of clay adhesion was directly related to the time after driving of the piles.
Cyclic Pile Load Testing—Loading System and Instrumentation
Authors: Lu TD , Miller VG , Fischer JA 
Published: March 2009

The scope, concepts, methodology, and details of a load application system and instrumentation for the successful operation of a series of cyclic pile load tests are described.
The purposes of the pile tests on an instrumented H-pile were to evaluate the dynamic behavior of piles under cyclic loading conditions for seismic analyses and design of a structure supported on piles. The scope of the pile load tests included a static vertical, cyclic vertical, and cyclic lateral loading, with a sustained constant vertical load.
A major requirement of the cycle testing was to apply a controlled varying load intensity to the pile in a specific wave shape at a specific frequency. To fulfill this requirement, an automated closed loop loading system, which consisted of an electronic-electromechanical control system interfaced with hydraulic loading components, was developed.
An instrumentation program was implemented to measure the static and cyclic response of the test pile to include (a) bending moments and axial compression of the pile during driving; (b) loads, moments, angular rotation, and deflections of the pile during testing; and (c) the configuration of pile after driving and after each increment of load application.
Stress and Deformation in Single Piles Due to Lateral Movement of Surrounding Soils
Authors: Wang MC , Wu AH , Scheessele DJ 
Published: March 2009

This paper presents a case history of structural damage due to lateral soil movement and an analysis of stress and deformation in the supporting piles. The project involved cast-in-place concrete piles cased in steel pipes having 40.6-cm (16-in.) outside diameter and 38.7-cm (15¼-in.) inside diameter. The piles extended through a 7.6-m (25-ft) oyster shell fill and a 17-m (55-ft) soft clay layer and penetrated 7.6 m (25 ft) into a compact sand stratum. Due to overloading at the top of the fill, the soil surrounding the piles underwent lateral movement and caused cracking in the pile caps.
The amount of lateral soil movement was measured using inclinometers. Based upon the measured soil deformation, lateral soil pressures were determined with appropriate moduli of subgrade reaction. The soil pressures were used as lateral loading on a single pile. Using a finite element computer program that was developed based upon the theory of beam on elastic foundation, the deformation of the single pile and the horizontal reaction and resisting moment mobilized in the pile cap were analyzed. By comparing the horizontal reaction and resisting moment with the structurally determined ultimate values, the results of the pile behavior analysis were checked favorably.
Ethylene Oxide Detection and Protection
Authors: Pritts IM , McConnaughey PW , Roberts CC , McKee ES 
Published: March 2009

Ethylene oxide is used as an intermediate for the synthesis of a wide variety of industrial compounds. Furthermore, its strong alkylating properties make it useful as a fumigant and sterilant, and therefore, it is used in hospitals. Recent concern for ethylene oxide's toxicity may result in lowering the threshold limit value (TLV) from 50 to 10 ppm. Clearly, detection and protection methods for ethylene oxide are of immediate concern.
The detection of ethylene oxide can be accomplished easily and quickly by using a recently developed detector tube system. This detector tube system employs two reactors, a detector tube, and a hand-operated pump. As ethylene oxide is drawn through the three-part detector tube, it is first converted to formaldehyde; the formaldehyde then reacts with xylene and sulfuric acid to form a quinoidal compound. The stain is proportional to the concentration of ethylene oxide present.
A system to measure the average ethylene oxide concentration by time weighted average (TWA) over a 4 to 8-h period also has been proposed. This system uses activated charcoal tubes with fairly large sampling beds and smaller back-up beds. Because of the volatility of ethylene oxide from charcoal beds, special precautions must be taken for storage and analysis of this system, such as storage over dry ice and cooling the carbon disulfide eluent with dry ice.
A gas mask canister has been developed to protect workers for over 8 h against 1000 ppm ethylene oxide concentrations. The service time has been determined by the break-through of 1 ppm ethylene oxide. The use of the detector tube and canister should provide workers with protection from exposure to ethylene oxide.
Toward the Nondestructive Characterization of Fatigue Damage in Composite Materials
Authors: Mordfin L 
Published: March 2009

This paper is based upon introductory remarks presented at the opening of the ASTM Symposium on Damage in Composite Materials. The cooperation between specialists in fatigue and in nondestructive testing, in the organization and implementation of the symposium, is marked as a noteworthy milestone in an era in which closer cooperation between these two groups will be needed in order to achieve enhanced quality in materials and manufactured products.
Experiences with an unusual form of damage in pultruded guys for antenna support systems are described to show that the development of meaningful test methods for composites may benefit from unconventional approaches. It is suggested, furthermore, that the development of voluntary standards for the nondestructive characterization of composite materials will succeed only to the extent that individuals with the relevant competences are encouraged to contribute to this important activity.
Fractographic Studies of Graphite/Epoxy Fatigue Specimens
Authors: Morris GE , Hetter CM 
Published: March 2009

Techniques have been developed for determining fracture directions and locating fracture origins for graphite/epoxy (Gr/EP) laminates that fail by overload. These techniques have used the scanning electron microscope (SEM) to identify failed epoxy component topographic features (hackles) that characterize overload failures. Now, the hackle interpretation technique is used to trace hackles back to fracture origin locations on the fracture surfaces of tensile failed Gr/Ep test coupons and structures.
Recently, these SEM studies have been expanded to include fatigue tested cross-plied Gr/Ep specimens. Patterns of arrest marks (striations) have been associated with tension-compression fatigue crack propagation for some Gr/Ep test specimens. The striation features are distinctly different in appearance from hackles; therefore, they present a promising topographic feature to differentiate tension-compression fractures from overload fractures in Gr/Ep composites. Visual, nondestructive testing, and SEM techniques that were used to identify the striation topographic features are described. Progress to date is presented on attempts to correlate observed striation patterns with fatigue damage growth in Gr/Ep test specimens.
Effect of Stacking Sequence on Damage Propagation and Failure Modes in Composite Laminates
Authors: Ratwani MM , Kan HP 
Published: March 2009

The effect of stacking sequence on damage growth and failure modes in composite laminates is discussed. Tests were conducted on AS/3501-6 graphite/epoxy coupons with four different stacking sequences. All laminates had the same percentage of 0, 90, and ±45 degree plies. Constant amplitude fatigue tests were performed at R (minimum to maximum stress ratio) = −1.0 and −∞. The specimens were periodically taken out of the testing machine and subjected to nondestructive inspection using X-ray radiography with diiodobutane.
The results of nondestructive inspection indicate that the direction of damage propagation depends on the stacking sequence in the composite laminate. The damage may propagate predominantly along the loading direction or in a direction at some angle to the loading direction, depending on the stacking sequence. Interlaminar stress analysis of four laminates was performed to correlate the direction of damage propagation with the nature of interlaminar stresses.
A Chronic Toxicity Test with the Marine Copepod Acartia tonsa
Authors: Ward TJ , Rider ED , Drozdowski DA 
Published: March 2009

A chronic toxicity test was developed for studying the effects of five toxicants (effluents) on the survival and reproduction of Acartia tonsa, a marine zooplankton. The test involves the exposure of copepods to three concentrations of each material (320, 100, and 32 ppm) for an entire life cycle. It is divided into three parts: (1) the reproduction of laboratory-cultured Acartia tonsa in breeding chambers containing the three concentrations of toxicants under static conditions; (2) sexual maturation of the F1 organisms in the toxicant concentrations under flow-through conditions; and (3) the reproduction of the F1 organisms under the same conditions as those established for Part 1, and the monitoring of the organisms' reproductive success, defined as the number of viable F2 offspring.
The results of the chronic tests were compared with data from an acute study conducted earlier. The chronic tests showed a significant reduction in organism survival, when compared with the acute tests (in the range of 1.0 to 0.1 percent of the 48-h LC 50 value). This paper highlights the relative simplicity of the chronic Acartia tonsa test procedure and demonstrates its twofold usefulness: (1) in the identification of a long-term effect and (2) in the comparison of the chronic toxicity of differing materials.