bluuebunny/crossref_metadata_2025 huggingface dataset:
End-Result Specifications—A Contractor's Viewpoint
Authors: Jones WH , Scherocman JA
Published: March 2009

Method-type specifications penalize a competent asphalt paving contractor by requiring the contractor to use prescribed equipment, materials, and methods to construct a particular pavement. End-result specifications, on the other hand, allow the contractor to use his available resources to accomplish the required end product in the manner of his own preference.

The Indiana State Highway Commission let to contract a paving project under end-result specifications. This contract, awarded to Magaw Construction, accepted the asphalt content, aggregate gradation, and pavement surface smoothness on the basis of statistical-type specifications. The quality control exercised by the contractor was excellent, with the penalties assessed being equal to only 1.24 percent of the value of the paving work.

A lack of knowledge by state personnel of the significance of end-result specifications and differences in sampling and testing techniques have, in the past, caused the assessment of many of the penalty points. The differences in the results obtained could be reduced on future projects, however, through the use of a certified asphalt technician approach to end-result specifications.
Application of Low-Cycle Fatigue Test Results to Crack Initiation from Notches
Authors: Truchon M
Published: March 2009

Fatigue crack initiation tests were carried out on notched specimens, with Kt values ranging from 1.4 to 4.2, made of a large variety of steels. The paper describes the application of the critical location approach to these tests on the basis of low-cycle fatigue data obtained on smooth specimens under Neuber control straining or under conventional reverse straining (Rε = (εmin/εmax) = −1).
Prediction Capability and Improvements of the Numerical Notch Analysis for Fatigue Loaded Aircraft and Automotive Components
Authors: Nowack H , Hanschmann D , Foth J , Lütjering G , Jacoby G
Published: March 2009

Because they combine minimum experimental expenses with a maximum flexibility regarding their application areas and objectives, numerical notch analysis methods have attained special importance among the presently available crack initiation life prediction methods.

The first part of this study gives the results of an evaluation program in which the prediction capability of the numerical notch analysis concept using the Neuber approach for the consideration of the notches was investigated. The loading histories considered are standard flight loading histories (TWIST and FALSTAFF), automotive histories, and simple, systematically varied loading histories. The test specimens were center notched and angle type, and the materials were high-strength aluminum alloys, Ti6-4, and others. The test results showed satisfactory predictions in many cases; however, unacceptable deviations occurred, especially under long-term random loading, after high peak loads, and under a high amount of compressive loads.

The second part of this study investigates the reasons for the deviations in the predictions. The main reasons are (1) inadequate consideration of the sequence effects on the damage accumulation, and (2) differences in the stress states and crack initiation processes at the stress raisers of the notched specimens and at the unnotched specimens.

A new damage evaluation procedure is proposed that is based on these test results. A more adequate definition of the crack initiation stage is attempted and a consideration of short cracks is provided.
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.
Effect of Light-Water Reactor Environments on Fatigue Crack Growth Rate in Reactor Pressure Vessel Steels
Authors: Törrönen K , Cullen WH
Published: March 2009

This paper presents an overview of the effect of light-water reactor environments on the fatigue crack growth rate in reactor pressure vessel steels. The effect of different variables known to influence the environmental assistance—stress intensity range, load ratio, frequency, temperature, water chemistry, and irradiation—is described. The fractographic phenomena and mechanisms of fatigue crack propagation associated with environmental influence is emphasized. An analytical approach for predicting the crack growth rates based on the hydrogen embrittlement model is described. Finally, a discussion of the effect of different transients occurring in the nuclear reactors on the crack growth rate predictions is presented.
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.
Beneficiation of Marginal Coastal Oregon Aggregates with Cement
Authors: Chang C , Hicks RG , Vinson TS
Published: March 2009

Coastal Oregon has a severe shortage of quality construction aggregates. There is, however, an abundant supply of lower quality, or marginal, aggregates. In an attempt to use marginal aggregates, the feasibility of beneficiation with cement has been investigated. Specifically, the optimum cement contents to stabilize three marginal aggregates (Tyee sandstone, marine basalt, dredge spoil sand) were determined. The resilient modulus and fatigue life characteristics were measured for the aggregates stabilized at the optimum cement contents. The influence of moist curing time and wetting and drying or freezing and thawing cycling on the properties measured were evaluated. The results indicated the resilient moduli of all the materials tested increased with moist curing time. The resilient moduli of the stabilized aggregates were not affected by freezing and thawing cycling, however, the moduli were reduced after wetting and drying cycling. The fatigue life characteristics, expressed in terms of tensile stress versus number of load repetitions to failure, were not significantly different for the moist cured stabilized materials compared to the stabilized materials subjected to wetting and drying or freezing and thawing cycling. The resilient moduli and fatigue life properties measured were used to arrive at typical layer thicknesses and layer equivalencies for road sections employing the cement stabilized marginal aggregates. The results indicate beneficiation of marginal aggregates with cement is economically justifiable.
Properties of Marginal Aggregates Treated with Asphalt Emulsion
Authors: Evans GL , Hicks RG
Published: March 2009

The suitability of asphalt emulsions for upgrading marginal aggregates has been evaluated. The aggregates tested included a high quality basalt, two low quality marine basalts, and a fine grained dune sand. Mix properties evaluated included diametral resilient modulus and diametral fatigue life for both as-compacted specimens and specimens conditioned by moisture exposure. Layered elastic design principles were used with the dynamic test results to develop layer equivalencies for emulsion treated marginal aggregates compared with hot mix asphalt concrete. The results indicate that beneficiation of marginal aggregate with asphalt emulsions should make acceptable paving mixes, particularly for low volume roads.
Ceramic Roadway Aggregates
Authors: Petty AV
Published: March 2009

Through a cooperative program between the Bureau of Mines, Tuscaloosa Research Center, and the Federal Highway Administration, ceramic aggregates having high wear- and polish-resistance were developed. Three-hundred aggregate compositions, incorporating a variety of low-cost “waste” materials were evaluated over a 30-month period. Aggregates were produced using conventional ceramic processing techniques and fired at temperatures ranging from 900 to 1500°C. British Wheel and Los Angeles Abrasion tests were used for initial screening of the aggregates. These data, in addition to raw materials costs, its availability, and energy requirements, were used to select nine compositions for circular track tests at Maryland and North Carolina Highway Department facilities. Economic evaluations showed that present production costs, based on a 1000 ton-per-day operation ranged from $10 to $120 per ton of material produced. Guyana bauxite was used as a standard, and several of the selected compositions developed surpassed the bauxite in performance and were lower in cost.
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.
Thermal Evaluation of One-Ply Sheet Roofing
Authors: Cash CG
Published: March 2009

This paper presents some preliminary data on the thermal analysis of one-ply roofing sheets. The differential scanning calorimetry (DSC) data show that DSC techniques may be used to identify the type of plastic or elastomer used in one-ply roofing sheets. Products manufactured by different producers, and weathered and unexposed specimens have different shaped curves. Once a library of curves has been established, DSC testing may be used not only to identify materials and their producers, but to show aging characteristics and degree and nature of damages from general exposure and environmental influences.
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.
Aquatic Invertebrates in Tolerance Investigations from Aristotle to Naumann
Authors: Anderson BG
Published: March 2009

The earliest use of aquatic invertebrates in tolerance research was carried out to answer questions concerning adaptation and evolution somewhat over a century and a half ago. The procedures were essentially the same as those we use today for bioassays in the determination of water quality. In the first studies that have been reported, freshwater invertebrates were subjected to seawater, and marine invertebrates were exposed to freshwater. Later, many workers carried out research on the effects of ions in various combinations and concentrations on both freshwater and marine invertebrates. Some investigators were interested in the actions of drugs. It was only about five decades ago that serious consideration was first given to the use of aquatic invertebrates as test animals for the determination of the toxicity of potential pollutants. The author reviews representative reports of tolerance studies in which aquatic invertebrates were employed as experimental animals up through the time of Naumann. This is followed by a brief exposition of the author's procedures using Daphnia magna as the test animal in the determination of apparent thresholds of toxicity.
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.
Flow-Through Toxicity Testing System for Molluscan Larvae as Applied to Halogen Toxicity in Estuarine Water
Authors: Roberts MH
Published: March 2009

The routine static toxicity test method for molluscan larvae is outlined. A new flow-through test method for molluscan larvae is presented with data from studies of halogen toxicity. The test involves containment of larvae in a mesh-covered chamber suspended in a small aquarium. The water in the basket is replenished every 7 min by raising and lowering the water level in the tank by means of an automatic tidal siphon. Improvements in the test system are under development.
Use of Polychaetous Annelids as Test Organisms for Marine Bioassay Experiments
Authors: Reish DJ
Published: March 2009

The procedures for culturing three species of polychaetous annelids from egg to egg under laboratory conditions are described for Neanthes arenaceodentata, Capitella capitata, and Ctenodrilus serratus. The materials and methods required to conduct short-term, long-term, and complete life-cycle bioassays are outlined. The importance and use of these test organisms in marine bioassays is discussed.
A Discussion of Fire Risk Assessment
Authors: Roux HJ
Published: March 2009

Fire standards have been characterized in the ASTM Policy on Fire Standards (1979) as either fire risk assessment standards or fire test standards. Although the need for fire risk assessment standards is evident, there is a lack of understanding of what a fire risk assessment standard is and how it is obtained. The role of ASTM Subcommittee E05.91 on Planning and Review, a subcommittee of ASTM Committee E-5 on Fire Standards, and its success in answering these questions is described. Related subjects such as definitions of risk, hazard, and safety, the effect of proximity, and determination of the potential for harm are discussed.
Legal and Economic Criteria for Test-Based Fire Risk Assessment
Authors: Brannigan VM , Dardis R
Published: March 2009

This paper defines test-based fire risk assessment as it is used for economic and legal analysis. Its economic use is illustrated by cost-benefit and risk-benefit techniques. Its legal use is discussed in the context of tort liability, contracts, and regulation. In both areas, there is a need for definition of the risks being measured, the confidence in the result, and the type of assessment and data being produced.
Design and Evaluation of Load Tests on Deep Foundations
Authors: Reese LC
Published: March 2009

The use of methods of prediction of the performance of deep foundations is strongly encouraged. The paper presents models for both axially loaded and laterally loaded deep foundations and shows examples of the use of the models. Internal instrumentation that can be used in future load tests is discussed, along with load test procedures. Information from load tests of instrumented deep foundations will allow improvements in the methods of prediction of the behavior of deep foundation under various kinds of loading.
State-of-the-Art Pile Design Practice—Current and Proposed as Reflected in Building Codes
Authors: Fuller FM
Published: March 2009

Building codes generally specify maximum allowable compressive stresses for basic pile materials that control the structural design of piles. Sometimes these prescriptive type provisions are qualified by performance type provisions that permit such allowable stresses to be exceeded under controlled conditions. Combined prescriptive and performance regulations governing pile foundation design and installation is recommended because totally prescriptive or totally performance type provisions are impractical under the present state of the art. A relatively high structural factor of safety must be reflected in allowable stresses for pile material to provide for the many uncertainties currently existing in pile foundation design and installation and the several conditions under which the actual structural factor of safety can be less than assumed. Until we have more precise answers to all of our problems in designing and installing satisfactory pile foundations, any move to reduce the structural factors of safety below current levels would be ill advised. An examination of the current allowable stresses and proposed increases indicates that under today's state of the art, a practical limit has been reached or in some cases exceeded and proposed increases are generally unwarranted or undesirable.
Interpreting End-Bearing Pile Load Test Results
Authors: Brierley GS , Thompson DE , Eller CW
Published: March 2009

Interpretation of pile tip settlement behavior obtained from rod telltales on fourteen full-scale test piles at five different sites indicates that the applied load can be divided into end-bearing and skin friction components. The end-bearing component is used to obtain stiffness information about the bearing stratum. An equation for estimating pile settlement based on information accumulated during this study is given, and a procedure is proposed to estimate settlement from downdrag forces. Information about bearing strata obtained from the load test results can be accumulated and used to assist with design of future end-bearing pile foundations.
Analytical Methods to Predict Pile Capacities
Authors: Cheeks JR
Published: March 2009

A comprehensive test pile program was conducted for a large manufacturing facility. During this program, several pile types, including timber, precast concrete, concrete-filled pipe, and shells were driven and load tested to failure. Prior to load testing, the ultimate pile capacity was predicted by three static and two dynamic techniques. After testing, the predicted and measured capacities were compared. The wave equation and the Dutch cone penetration soundings resulted in the most consistent predictions.
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 Transfer from Bored, Cast-in-Situ Piles in London Clay
Authors: Cooke RW
Published: March 2009

This paper presents some measurements of the distribution of load transfer from the shafts of instrumented, bored, cast-in-situ concrete piles formed in London clay using a limited number of installation techniques. The measurements were included in a study of whether the use of bentonite slurries to stabilize open bore holes prior to concreting inhibits the development of friction on the shafts of piles in stiff clays. The instrumentation consisted of rod extensometers of various lengths and vibrating-wire gages clamped to the reinforcing cages. Devices attached to the bottom of each reinforcing cage prevented the development of any bearing forces at the pile bases. A method of correcting the extensometer observations for bending of the laterally unsupported length of shaft cased through fill is described, and the results are compared with a finite element analysis of the pile-soil system.
Timber Piles in Standards, Codes, and Practice
Authors: Diekmann EF
Published: March 2009

This paper presents a limited review of the standard and code provisions relating to timber piles from the turn of the century to the present. The provisions relative to axial stress in ASTM Establishing Design Stresses for Round Timber Piles (D 2899-74) are discussed and compared to some of the background experimental data. The conclusion is drawn that ASTM Method D 2899-74 is generally satisfactory regarding axial stresses but has specific weaknesses requiring changes. While no changes are forseen in the immediate future in the use of timber piles for 335 to 445 KN (40 to 50 ton) loads, it is suggested that timber piles may be utilized for higher capacity requirements. The view is expressed that limitations on pile material stresses are not proper in a building code, that such limitations are more appropriately placed in guidelines for foundation engineers selecting piles for specific applications.
A Rational Procedure for Evaluating the Behavior of Impact-Driven Piles
Authors: Holloway DM , Clough GW , Vesic AS
Published: March 2009

A numerical solution has been developed using a finite difference formulation to simulate the one-dimensional impact wave propagation behavior and subsequent static load test performance. Based on this solution, the importance of residual driving stresses in properly interpreting pile behavior under axial loads is examined. This paper (1) briefly describes the analytical procedure developed by the authors to incorporate residual stresses explicitly, (2) applies the procedure to a documented pile load test to demonstrate the concepts developed, (3) examines the consequences of ignoring residual driving stresses in interpreting/predicting pile behavior under axial loads, and (4) demonstrates the influence of various parameters on the predicted pile performance.
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.
Interpretation of Load Tests on High-Capacity Driven Piles
Authors: Leonards GA , Lovell D
Published: March 2009

Pipe piles and H-sections about 35 m (115 ft) long were driven through 24 m (80 ft) of alluvial materials to bearing in a stratum of glacial till about 15 m (50 ft) thick overlying bedrock. Load tests were conducted to establish the equipment and driving resistance needed to develop a capacity of 3560 kN (400 tons) solely in the underlying tills. Interpretation of these tests proved to be a challenge that led to the development of a new technique to analyze load transfer using only data obtained from conventional pile load tests. Among the conclusions reached were (1) ultimate shaft friction of steel piles driven into very stiff to hard tills did not exceed 120 kPa (1.25 tsf); (2) for piles as large as 460 mm (18 in.) in diameter, ultimate shaft friction is not necessarily mobilized before the pile capacity is reached; and (3) loading and unloading a pile can cause irreversible changes in the existing as well as on the ultimate shaft friction—methods of interpreting pile load tests to determine load transfer or residual stresses that rely on these changes being negligible, should be used with caution.
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.
Building Code Requirements for Maximum Design Stresses in Piles
Authors: Rempe DM
Published: March 2009

The maximum pile design stresses specified in building codes exert a strong influence on the design of pile foundations and have a major impact on the efficiency of utilization of pile materials. This paper presents an overview of code requirements in the United States, with emphasis on model codes and the recommendations of technical societies and trade organizations, but including a sampling of requirements in local codes. This is followed by a discussion of the current trend toward higher design stresses, potential problems resulting from this trend, and means by which codes can be structured so as to minimize or avoid these problems.
Field Evaluation of Caisson-Shale Interaction
Authors: Spanovich M , Garvin RG
Published: March 2009

Load tests were conducted on ten full-sized cast-in-place drilled caissons (bored piles, drilled shafts) of varying diameter. Three caissons were tested to evaluate end-bearing on the surface of fissile shale; five caissons were tested to evaluate side shear of shale sockets; one caisson was tested to evaluate end-bearing below weathered shale; and one caisson was tested to evaluate side shear in soil. Nine of the shale-bearing caissons tested exhibited subgrade failure, observed as excessive settlement, while the remaining shale-bearing caisson, drilled to end-bearing below the weathered shale, failed by shearing of the concrete shaft. The end-bearing test values exceed commonly employed empirical design values by factors ranging from 3 to 23. The shale sockets supported loads of at least one-third of and in some cases exceeding the ultimate end-bearing load.
Influence of Driving Stresses on the Development of High Pile Capacities
Authors: Thompson CD , Thompson DE
Published: March 2009

The impact stresses have been measured near the top of piles as they are driven to practical refusal in very dense granular soils and shale bedrock. These stresses have been compared with capacities determined from static load tests. The comparisons were carried out on 24 piles of various types and lengths driven with a wide range of hammers and capblocks at different sites. They indicate that the ultimate bearing load divided by the pile shaft cross-sectional area during driving averages 1.2 times the impact stress at practical refusal with a standard deviation of ±20 percent. This is in close agreement with the Case method wave equation analysis. It is concluded that, for conditions similar to those tested, driving criteria to establish a required bearing load may be estimated from impact stress measurements at the top of the pile. Other methods, such as conventional dynamic formulas, are not as suitable, as they cannot measure the effects of hammer and cap block variations.
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.
Sampling and Analysis of Airborne Fenitrothion and Tris(2-Ethylhexyl)Phosphate
Authors: Krzymien ME
Published: March 2009

An analytical technique is described for simultaneous determination of fenitrothion and tris(2-ethylhexyl)phosphate (TEHP) in air. Total airborne (vapor and aerosol) fenitrothion and TEHP were collected in glass tubes 75 by 6.3 mm outside diameter containing a 10-mm plug of Tenax GC. Air was drawn through the adsorber at a rate of about 1 L/min for a period of up to 4 h to measure the dosage of fenitrothion and TEHP or for 2 to 3 min to determine timewise variations of concentration. The break-through volume of the adsorbers was larger than 360 L at a sampling rate of 1 L/min. The material collected on Tenax GC was thermally released directly into a gas chromatographic column and analyzed using a thermionic detector. Cascade impactors were used to collect aerosol and measure the drop-size distribution over a range of 1 to 30 μm. The concentrations of fenitrothion and TEHP measured in field experiments varied over a range of 3 × 10−12 g/L to 2 × 10−8 g/L and 5 × 10−12 g/L to 2 × 10−10 g/L, respectively. The precision of the method was better than ± 10 percent using different adsorbers and ± 5 percent for the same adsorber. Field tests were conducted in New Brunswick forests during the 1980 spruce budworm control program.
Large Volume Sampling Without Preconcentration for Continuous Gas Chromatography
Authors: Phillips JB , Valentin JR , Carle GC
Published: March 2009

A milligram quantity of adsorbent material was placed at the head of a gas chromatographic column. The initial part of the column itself served as this adsorbent in some experiments. A continuously flowing gaseous sample was passed through a length of narrow bore metal tubing, the precolumn adsorbent, and the gas chromatographic column. A computer generated signal heated the metal tubing which heated the sample gas stream and the precolumn adsorbent. The changing adsorbent temperature generated a changing concentration of adsorbable substances in the gas stream. Thus, the computer generated a chemical concentration signal usable for chromatographic analysis. This technique is related to chromatographic analysis using preconcentration but has several important advantages.
Determination of Hydrogen Cyanide in Air by Ion Chromatography
Authors: Dolzine TW , Esposito GG , Gaffney RJ
Published: March 2009

This paper describes a new procedure for the determination of hydrogen cyanide (HCN) concentrations in air. Airborne HCN is entrained in an impinger containing aqueous alkali and subsequently converted to sodium formate; the latter is quantitatively measured by ion chromatography. The collection procedure, reaction conditions, and chromatographic method are described. Interferences and the use of ion exchange resins for sample clean-up were investigated also. The precision and accuracy of spiked and air samples are presented.
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.
Damage Documentation in Composites by Stereo Radiography
Authors: Sendeckyj GP , Maddux GE , Porter E
Published: March 2009

The results of an experimental study of penetrant enhanced stereo X-ray radiography for damage documentation in resin-matrix composite materials are presented. The results show that penetrant enhanced stereo radiography can describe accurately the spatial distribution of matrix cracks and delaminations. Presence of fiber fractures can be inferred from the matrix cracking patterns.
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.
An Investigation of Cumulative Damage Development in Quasi-Isotropic Graphite/Epoxy Laminates
Authors: Masters JE , Reifsnider KL
Published: March 2009

Results of an experimental investigation of cumulative damage development in two unnotched quasi-isotropic graphite/epoxy laminates subjected to quasistatic tension and tension-tension fatigue are presented. Damage development in the form of transverse cracking in all off-axis laminae, longitudinal cracking, and delamination was monitored via the surface replication technique. Results of the study include a detailed description of the chronology of damage development prior to failure. Evidence also is presented in support of a damage model based on the concept of a characteristic damage state.