bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Various Accelerating Chemical Admixtures on Setting and Strength Development of Concrete
Authors: Rosskopf PA , Linton FJ , Peppler RB 
Published: February 2009

Abstract
A study of the rate of hardening of concretes which contain inorganic accelerators demonstrates the superior performance of calcium chloride. However, there are significant changes in the compressive strength of concretes at various ages when accelerators are employed. Calorimetric studies of cement mortars show the advantages as an accelerator that calcium chloride maintains over other inorganic salts. Also, calorimetric tests demonstrate what appears to be different mechanisms of acceleration between different kinds of accelerators. Differential thermal analysis (DTA) techniques were applied to a study of the effect of calcium chloride and calcium formate on the early stages of hydration of a cement. DTA patterns show definite differences between the function of the accelerators.
Comparison of Lap Shear Test Specimens
Authors: Guess TR , Allred RE , Gerstle FP 
Published: February 2009

Abstract
The single lap shear test specimen, a method for measuring the shear strengths of structural adhesives, was evaluated in a combined experimental and analytical study. The shear strengths of two structural adhesives were measured with the conventional thin adherend lap shear specimen and with several thick adherend configurations. Shear strengths obtained from thin specimens were too low: failure was controlled by the tensile (peel) strength of the adhesive/adherend interface rather than by the adhesive shear strength. Equally significant was the finding that the relative shear strengths of the two adhesives measured with the thin specimen configuration were opposite the results from the thick adherend specimens. The apparent shear strengths from thick adherend test specimens increased with increasing adherend thickness, an expected result; however, they decreased with increasing adhesive thickness, a trend which did not agree with published analyses. This anomaly is explained by finite element analyses of the shear and normal stress gradients in the adhesive layer.
Effect of Antibuckling Constraint on Determination of Critical Stress Intensity Factor of Aluminum Sheet
Authors: Bucci RJ , Sha GT 
Published: February 2009

Abstract
Tests were made to compare Kc values for Alclad® 7475-T761 determined from 16-in. (406-mm) wide, center-cracked tension panels tested with and without guides designed to prevent buckling from intensifying the crack tip stress field. The tests show that for sheet thicknesses ranging from 0.06 to 0.15 in. (1.52 to 3.81 mm) a multiplication factor of 0.87 is required to convert Kc values obtained employing antibuckling guides to corresponding values obtained without guides. Above 0.15-in. thickness, test panels appeared to be of sufficient stiffness to prevent buckling without the use of guides, and therefore the conversion factor is unity.
Structural Strength of Short, Axially Loaded Columns of Reinforced, Laterized Concrete
Authors: Adepegba D 
Published: February 2009

Abstract
Laterized concrete was defined as concrete in which “stable” laterite fines replace sand. Reinforced and unreinforced laterized concrete short columns of the same dimensions were cast from three mixes by weight and tested in axial compression after approximately 28 days. Strains were taken on steel and laterized concrete at about the mid-height of the columns. The maximum strain recorded on laterized concrete varied between 0.12 and 0.21% and that on steel varied between 0.12 and 0.20%. The ultimate loads of reinforced laterized concrete short columns were observed to be approximately the same as the ultimate loads for unreinforced laterized concrete columns of the same dimension as the reinforced columns.
Shear and cleavage modes of failure were recognized in unreinforced laterized concrete short columns; however, lateral reinforcement prevented the development of short vertical cracks that led to failure in the reinforced laterized concrete short columns.
The load factor for reinforced laterized concrete short columns is about 2. It is concluded that 1:2:4 mix by weight of laterized concrete may not be suitable for structural works because of the large deformation at initial cracking in all the columns cast from the mix. It is recommended that design practice of laterized concrete structures should be based on the conservative elastic method until more information is available about the behavior of the material.
Impact Three-Point Bend Testing for Notched and Precracked Specimens
Authors: Server WL 
Published: February 2009

AbstractTesting and data analysis procedures developed from a recently completed fracture toughness testing program on ferritic nuclear pressure vessel steels are presented. These procedures describe the measurement of dynamic fracture toughness at stress intensification rates near 105 MPa√m/s using instrumented impact testing of three-point bend specimens. These procedures have been submitted to several ASTM task groups, and it is hoped that these guidelines will be incorporated into current and future interlaboratory activities eventually leading to a standard method for testing.
Tapered Tensile Specimen for Stress Corrosion Threshold Stress Testing
Authors: Jonas O 
Published: February 2009

AbstractA new type of specimen for determining stress corrosion threshold stress is described. The specimen has a tapered gage length that provides longitudinal stress distribution with a maximum to minimum stress ratio of 1.85. After a constant load stress corrosion test, the surface of the specimen is inspected and the gage length is longitudinally sectioned. In long-time tests the minimum stress at maximum diameter at which cracking is found approaches the threshold value. Applicability of the specimen has been confirmed by tests of several materials in different environments. The specimen can also be used for the testing of stress-induced pitting.
The Polishing Characteristics of Common Rock Types Used as Aggregate in Bituminous Pavement Surfaces
Authors: Dahir SH , Meyer WE 
Published: February 2009

Abstract
Bituminous pavement surfaces constructed with aggregates of different rock types, or of the same rock type but from different sources, often exhibit different friction characteristics under comparable traffic conditions. Rock type, abrasive size, number of wheel passes, and contact pressure between surface and tire have been generally recognized as primary factors that control the polishing process. To investigate the relation of these factors to rock properties, but without bias caused by shape and size of the aggregate or by mix design, flat surfaces of six rock types varying in texture and mineral composition were polished in a laboratory procedure. Silica in eight grades ranging from 5 to 105 μm was employed as the abrasive in polishing the surfaces with a reciprocating rubber pad apparatus, and different abrasive sizes were used in succession. Contact pressure was normally 15 psi (103 kPa), but was varied in some cases. The polish attained was measured as friction with a pendulum tester after each cyle of 6000 passes of the polishing pad. The results indicate that the susceptibility to polishing increases with the softness and homogeneity of the rocks, the fineness of the abrasive, the number of polishing cycles, and increased contact pressure.
The Particle-Size Distribution in AC Fine Test Dust
Authors: Johnston PR 
Published: February 2009

Abstract
AC test dust is widely used in studying the performance of filter media; however, controversy exists over what constitutes the actual particle-size distribution in the fine-grade material. Presented here are (1) an explanation of the difference of opinion regarding this distribution, (2) an example of problems that will arise because of the difference in opinions, and (3) a plea for workers in this field to resolve this difference.
An Assessment of Reactor Pressure Vessel Irradiated Materials Considerations
Authors: Stahlkopf KE , Marston TU 
Published: February 2009

AbstractRegulatory action has contributed almost 4% to the accumulated outage time of the nuclear plants. This translates into a loss of between $66 million and $280 million to the economy. Radiation-embrittlement-related regulatory actions and associated outages are predicted for the future. This paper evaluates the current regulations related to radiation embrittlement and discusses some of the current embrittlement issues. Weaknesses in the regulations are identified and recommendations for future research to overcome these weaknesses are presented.
Calibration of the Side-Grooved Modified Wedge-Opening-Load Specimen
Authors: LeFort P , Mowbray DF 
Published: February 2009

Abstract
The modified wedge-opening-load (WOL) specimen introduced by Novak and Rolfe is now commonly employed to establish crack growth rate and threshold of stress corrosion cracking KIscc data. The present paper is concerned with the stress intensity factor solution for this specimen with 10% side grooving. Finite element and experimental compliance studies were undertaken to define the stress intensity factor solution in terms of crack mouth opening displacement. The analytical and experimental results obtained were found to be in excellent agreement. The results also verify the use of Wilson's finite element stress intensity calibration of the T-type WOL specimen when the effect of the side grooves is accounted for.
Effect of Temperature on Stress Corrosion Cracking of 300M Steel
Authors: Ryder JT , Pickel FM 
Published: February 2009

Abstract
The effect of temperature on stress corrosion cracking of high-carbon 300M high-strength steel in deionized water was investigated. Tests were conducted with wedge-opening-load specimens at 0, 23, and 90°C. Stress corrosion crack growth rates above the stress corrosion cracking threshold KIscc were found to increase with increasing temperature and to be essentially constant at each temperature. The crack growth rates appeared to be described by an Arrhenius-type rate expression. The apparent stress corrosion cracking threshold KIscc at 23°C was approximately 12.1 MPa · m½ (11 ksi·in.½) and at 90°C, 16.5 MPa·m½ (15 ksi·in.½). At 0°C, KIscc appeared to be lower than at 23°C.
Computer-Controlled Decreasing Stress Intensity Technique for Low Rate Fatigue Crack Growth Testing
Authors: Saxena A , Hudak SJ , Donald JK , Schmidt DW 
Published: February 2009

AbstractAn automated test system utilizing computer control was developed to obtain crack growth rate data down to the fatigue crack growth threshold with a decreasing stress intensity technique and compact type specimens. The starting stress intensity range ΔK0 was chosen to yield crack growth rates in the range of 2.54 × 10−8 m/cycle (10−6 in./cycle) and subsequent values of ΔK are controlled to the equation ΔK = ΔK0 exp [C(a − a0)] (a0 and a are the initial and instantaneous crack lengths and C is a test variable). Crack length is continuously monitored by using the elastic compliance technique, thereby enabling ΔK to be decreased continuously. Comparison crack growth data were also obtained by the more conventional constant load amplitude or K-increasing method. Excellent agreement was observed between data obtained from the two procedures for a Society of Automotive Engineers 1045 steel at load ratios R of 0.1 and 0.5, an A356-T6 sand-cast aluminum alloy at load ratios of 0.1 and 0.8, and a 2219-T851 aluminum alloy at a load ratio of 0.1.
Frequency, Stress Ratio, and Potential Effects on Fatigue Crack Growth of HY130 Steel in Salt Water
Authors: Vosikovsky O 
Published: February 2009

AbstractFatigue crack growth rates over wide ranges of stress intensities (from threshold to nearly critical stress intensity) were measured on HY130 steel in 3.5% sodium chloride aqueous solution at several cyclic frequencies, stress ratios, and potentials. The growth rates are compared with reference data measured in laboratory air. The growth rate curves for both environments can be approximated by two linear sections converging at low stress intensity ranges to the same threshold, which depends only on the stress ratio. The upper parts of the lines with lower slopes converge again to the point where maximum stress intensity approaches its terminal value. As a result, the maximum environmental acceleration of crack growth appears at intermediate stress intensities, and it increases with decreasing frequency and potential. Data indicate a relatively low susceptibility of HY130 steel to corrosion fatigue. With increasing stress ratio R the fatigue crack growth threshold is shifted to lower stress intensity ranges by the same amount in both air and salt water environments. The effect of R on growth rate can be introduced into a power law expression.
Mechanical Properties in Bending at Elevated Temperature of High Strength Copper Alloy Flat Spring Materials
Authors: Fox A , Fuchs EO 
Published: February 2009

Abstract
The yield strength and modulus of elasticity in bending for several high strength copper alloy flat spring materials were determined in the temperature range 23 to 232°C (73 to 450°F) by both static and dynamic measurements. Results obtained by both methods are compared with those obtained by using a simple, short-time stress-relaxation test, and their applicability to the design of flat springs or connectors is discussed. The short-time stress-relaxation test is proposed as a simple acceptance test for flat spring materials. The alloys studied include one copper-nickel-tin alloy strengthened by spinodal decomposition (92% copper-4% nickel-4% tin), copper beryllium alloy (CA 172), copper cadmium alloy (CA 162), and copperiron-phosphorus alloy (CA 196). Long-time stress-relaxation data (2000 h) for the temperature range 23 to 232°C (73 to 450°F) confirm the observations made during the short-time relaxation tests, which showed that for extended service life applications springs made from either precipitation heat-treated CA 172 or appropriately aged 9244 alloy would operate satisfactorily at temperatures below 121°C (250°F) while those made from either of the other two alloys would not. Similar conclusions could not be drawn on the basis of bending yield strength.
Evaluation of Correction Methods for Determining Load-Independent Knoop Microhardness
Authors: Young CT , Rhee SK 
Published: February 2009

Abstract
The correction methods proposed in the literature for determining load-independent Knoop microhardness were surveyed. The methods were evaluated by using the results from seven samples and two testers. Adding a constant correction factor for each sample to the measured long diagonals to obtain the unrecovered diagonal lengths was found to be quite successful. The correction factor includes terms from elastic recovery, visibility error, and calibration error. This factor, when applied, corrects the elastic recovery in the diagonals and the systematic errors associated with the tester employed, and thus results in Knoop hardness numbers independent of load and tester, which can be taken as the true hardness. The correction factor is load-independent but varies with sample and tester.
Two methods in the literature, a trial and error approach and an extrapolation technique, were found to work equally well for the seven samples in determining the correction factors and the load-independent hardness numbers. The approach attempting to correct the applied load with a term representing the minimum indenting load proved to be unsatisfactory.
Interlaboratory Measurements of Amphibole and Chrysotile Fiber Concentration in Water
Authors: Chopra KS 
Published: February 2009

Abstract
This paper presents the results of an evaluation of high-magnification microscopic techniques used to analyze fiber contamination in water conducted by an ASTM Task Group under Subcommittee E04.11 on Electron Metallography. These techniques offer a feasible means of measuring relatively low levels of fiber contamination in environmental water samples. Other bulk-type methods lack the needed sensitivity and selectivity. The transmission electron microscope is the best basic instrument for the analysis, particularly when it is equipped with selected area electron diffraction and energy-dispersive spectroscopy capabilities. The mean fiber concentrations by different groups agree within a factor of two. The interlaboratory reproducibility of 50% can be expected in relatively clean water samples unless the concentration is low. In samples with high concentrations of interfering solids, the precision will not be as good. Interlaboratory reproducibility of 25% is as good as the method can provide. When applied on a broad scale there are variable and significant losses associated with the condensation washing of samples containing amphibole. The losses are low and less varible when condensation washing is used to prepare samples containing chrysotile.
Comparison of Cotton Fiber Fineness and Maturity on Air-Flow Instruments
Authors: Lawson R , Ramey HH 
Published: February 2009

Abstract
Fineness and maturity measures were compared on two groups of cotton samples tested with the Micronaire, Arealometer, and IIC-Shirley fineness/maturity tester; one group was also tested with the Causticaire and sodium hydroxide maturity methods. Most correlations of the various parameters were high for Group A samples composed of four cultivars of Gossypium hirsutum L. The correlations were usually lower for Group B, which was made up of three species and several cultivars. Comparable parameters from different instruments were not always on the same level because of different calibration standards and procedures. However, if the correlation between methods is high, one can move from one measurement to another with a regression equation.
Proportional Biaxial Cyclic Hardening of Annealed Oxygen-Free High-Conductivity Copper
Authors: Lamba HS , Sidebottom OM 
Published: February 2009

AbstractCyclic-dependent hardening of annealed metals is by now a well-known experimental phenomenon. The annealed metal, when cycled between equal tensile and compressive strain limits, develops increasing stresses with each strain reversal. However, most previous experimental work on cyclic hardening has been restricted to axial or torsional loading. In this investigation hollow circular cylinders of annealed oxygen-free high-conductivity copper were subjected to combined axial-torsional cyclic proportional strain histories. The stress-strain histories for different proportional strain paths were correlated on the basis of effective stresses and strains defined previously by Tresca and Mises, and the correlations using Tresca's definitions were shown to be more representative than those of Mises. Power law hardening constants were determined for each stress-strain reversal. The power law hardening constants for axial cycling were predicted with reasonable accuracy from the corresponding torsional constants by employing correlations based on Tresca's definitions of effective stresses and strains.
Improvement of Sheet Metal Strength by Localized Thermal Shocks
Authors: Trasi SR , Hsu TR 
Published: February 2009

Abstract
In two previous papers, the authors presented results of a new process of introducing beneficial residual stresses in a sheet metal strip containing a small circular hole by a single thermal shock applied over an annular region concentric with the hole. In this paper, it is shown that multiple thermal shocks over separate annular regions are considerably more advantageous in introducing such beneficial residual stresses in the same sheet metal and in permitting wider tolerances for such variables as locations, sizes of shock zones, and strengths of the shocks for desired degree of benefit.
Biaxial Analogs of Triaxial Stresses
Authors: Ehrenburg DO 
Published: February 2009

Abstract
In the case of composite materials such as concrete and natural rocks, fracture is resisted by internal friction, cohesion of the matrix, and adhesion at the interfaces. Although the behavior of an interface is clearly understood only when it is acted on by tensile forces, rock mechanics is primarily concerned with compressive forces. The apparent difficulty is circumvented by breaking down any given stress system into two components: an isotropic pressure and a tensile biaxial stress. The strength indicated by the latter component is precisely equal to that of the given stress system. Thus a condition of triaxial compression can be transformed into one of biaxial tension. An analysis based on this transformation indicates that the strength of composite materials in equal biaxial compression is considerably greater than in unconfined compression; this relationship becomes the keystone of a strength theory for composite materials.
A New Fixture for Fatigue Testing
Authors: Min BK , Raj R 
Published: February 2009

Abstract
A new type of fixture has been designed for low cycle fatigue testing. The fixture provides good alignment and reduces the setup time to a minimum. It is especially useful for testing at elevated temperatures. If specimens with uniform cross section in the gage length are used, then the need for a diametral strain gage is eliminated. The fixture is presently being used to measure low cycle fatigue crack growth in 316 stainless steel at elevated temperatures.
Compliance Correction for Determining Load-Line Energies for Compact Fracture Toughness Specimens
Authors: Server WL 
Published: February 2009

AbstractA compliance correction technique has been used to calculate energies in the compact specimen test measured at the specimen loading line using the machine ram displacement. The compliance-corrected results for nine pressure vessel steels tested at temperatures of room temperature, 71°C, and 177°C have been compared with the direct measurement (standard clip gage) approach, and the results show essentially a 1:1 relationship with a correlation coefficient of 0.997. This technique should be useful for determining elevated temperature, ductile fracture toughness values and for tests in which the normal clip gage (or other technique) fails to operate.
A Modified Procedure for Measuring the Maximum Specific Gravity of Bituminous Paving Mixtures
Authors: Ishai I , Tons E , Chritz AP 
Published: February 2009

Abstract
An accurate measurement of the maximum specific gravity of bituminous paving mixtures Gmm is needed for a reliable air voids analysis of the mixtures in the design and control phases. Since most actual bituminous mixtures combine absorptive aggregates, some difficulties have been encountered with the use of some current procedures for measuring Gmm. This paper presents a procedure for measuring the maximum specific gravity with the use of methanol. The good wetting ability of the methanol, together with its insignificant dissolvent characteristic, enables it to be used as a volumetric liquid for realistic measurements of Gmm. These properties eliminate the difficulties in expelling the trapped air bubbles even without vacuum as well as ensure almost no asphalt dissolution and thus no penetration of liquid inside the aggregate surface voids that are impermeable to asphalt. In general, the test was found to be fast and simple, with highly repeatable results.
Strain Criteria for Fatigue Fracture of Metals at High-Cycle Loading
Authors: Troshchenko VT 
Published: February 2009

Abstract
The paper deals with the features of inelastic straining and fatigue fracture of metals in high-cycle loading. It is shown that the use of cyclic strains enables one to study the kinetics of cyclic deformation and fatigue damage accumulation with different loading histories, to consider the stress-strain state of structural elements with stress concentration, to formulate strain criteria for the fatigue fracture of metals involving various factors, and to develop methods for the accelerated determination of the fatigue limit.