bluuebunny/crossref_metadata_2025_split huggingface dataset:
Early Assessment of Concrete Quality by Accelerating Compressive Strength Development with Heat (Results of ASTM's Cooperative Test Program)
Authors: Wills MH 
Published: February 2009

Abstract
Rapid concrete construction practices have led to increasing pressure to assess the quality of concrete at a very early age. Therefore, a cooperative test program was conducted among nine laboratories to evaluate several existing test procedures involving the use of either hot water, boiling water, or the heat of hydration of portland cement to provide heat necessary to accelerate the compressive strength development of concrete. Depending upon which procedure was employed, the amount of acceleration ranged from 1.1 to 2.5 times the strength developed after the same period of moist curing. Statistical analyses of the data justified adoption of a standard method that can be used to judge the quality of concrete soon after mixing. This method involves three procedures of accelerated curing which are limited to concrete made with the same materials and tested by the same laboratory. It has been designated ASTM C 684-74 (Making, Accelerated Curing, and Testing of Concrete Compression Test Specimens). Use of it, under the conditions stated therein, results in as reliable an evaluation of the quality of the concrete at one or two days of age as compared to that measured at 28 days of age according to ASTM C 31-69 (Making and Curing Concrete Test Specimens in the Field).
Holographic Interferometry for Measuring Swelling of Hardened Concrete
Authors: Goldberg JL , O'Toole KM , Roper H 
Published: February 2009

Abstract
Holographic interferometry is used to study the deformation of one surface of a concrete test specimen while water is allowed to diffuse into the body of the material. The potential of this new approach for examining the dynamic behavior of swelling concrete is demonstrated by applying the technique to two hardened concrete test specimens made with different aggregate materials.
Freezing and Thawing Tests and Theories of Frost Damage
Authors: Blachère JR , Young JE 
Published: February 2009

Abstract
Cyclic freezing and thawing tests on structural clay materials are reported. These results and those of recent studies on the freezing of water in consolidated porous materials and the theories of frost damage are used to discuss the mechanisms of pressure generation and relief mechanism. It is concluded that the major mechanisms of stress generation and relief during the freezing of water in porous materials may be different for small or large cooling rates, and that it is probable that freezing and thawing tests can be accelerated, although it should be done with great caution.
Mechanisms of Acceleration by Calcium Chloride: A Review
Authors: Skalny J , Maycock JN 
Published: February 2009

Abstract
Calcium chloride (CaCl2) is a well-known accelerator of the hydration of concrete. Its activity is very complex, and a meaningful mechanistic interpretation requires an assessment of the effect of CaCl2 on each of the individual clinker mineral components. This paper reviews the considerable literature associated with hydration acceleration of calcium silicates, aluminates, and ferrites in the presence of CaCl2. It attempts to cover all of the most meaningful data and observed effects and to relate these effects to various proposed mechanisms. Where appropriate, the reviewed work is critiqued, and suggestions for potentially important new fields of research are offered.
Simulating Rain Impact Damage to Supersonic Missile Radomes
Authors: Smith DG , Kinslow R 
Published: February 2009

Abstract
A test simulating the rain impact damage to two ceramic missile radomes traveling at supersonic speeds is described. A water-jet gun has been developed which fires a short burst of water at speeds up to 5000 ft/s (1524 m/s). This gun was used to simulate the impact of raindrops on the radomes. Equations are given relating the crater volume and area of a single jet impact to the energy of the jet. Then equations are given which express the cumulative damage as a function of impact angle, drop size distribution, velocity, and rain field length and intensity. A computer code has been written to solve these equations. The computer code gave results that agreed well with an actual rocket sled test. The code was used to predict the damage for a new set of conditions, and the water-jet gun was used on full-scale radomes to simulate the predicted rain impact damage.
A New Technique for the Study of Cement Hydration by Scanning Electron Microscopy
Authors: Taylor DH 
Published: February 2009

Abstract
A new scanning electron microscopy technique is described which permits the study of cement hydration in greater detail than by other methods. Its chief advantages are (1) high sensitivity to early stages of hydration; (2) ability to detect amorphous as well as crystalline phases; and (3) ability to distinguish the behavior of individual components (cement or aggregate) of concrete during hydration. Examples of results obtained by this technique are presented.
Static and Impact Behavior of Graphite/Epoxy Composite Laminates Containing Third-Phase Reinforcement Materials
Authors: Adams DF , Perry JL 
Published: February 2009

AbstractA series of graphite/epoxy composite laminates containing four different types of third-phase reinforcement materials were fabricated, incorporating an anisotropic ply lay-up pattern. Both thick and thin laminates were used. Static tensile, flexure, and short beam shear specimens and Charpy impact specimens were tested, the latter with an instrumented impact tester. The fracture surfaces of the static flexure and the Charpy impact specimens were then examined in detail with a scanning electron microscope. Observed similarities and differences between the static flexure and impact fracture characteristics of a given composite were noted and referred to the corresponding energies absorbed to failure. Similar comparisons were made between the various material combinations.
Economic and Performance Aspects of Increasing Insulation on the Temperature of Built-Up Roofing Membranes
Authors: Cash CG , Gumpertz WH 
Published: February 2009

Abstract
The energy crisis has raised demands for a substantial increase in the insulation of roofing systems, and calculations in this paper confirm that the financially most favorable insulation has a thermal resistance much higher than that of presently used systems. Objections have been raised to the increase in the thermal resistance of roofs on the basis that this will result in a substantial increase of the temperature range to which membranes are subjected, with resultant increase of membrane cracking from temperature movement. We have made a number of calculations to check on the justification of such concerns.
The results of our work, based on a number of simplifying assumptions, show that increasing the thermal resistance of insulation, over presently prevailing standards, does not significantly enlarge the thermal range to which roofing membranes are presently subjected. This applies both to changes in the ambient temperature and to solar radiation. Insulation thickness should therefore be based on considerations of economy and energy conservation, but there are still unresolved problems of decreasing impact resistance and lateral stability.
Reliability of Whittemore Gage Length Measurements
Authors: Ashton HE 
Published: February 2009

Abstract
A large number of measurements on a nickel-steel alloy bar and on brass inserts in the bar were taken to determine if wear was taking place in the alloy standard or in the Whittemore gage. Microscopic examination was used to confirm the dimensional results. It was concluded that neither the gage nor the brass exhibited significant changes in readings but that the alloy showed a change after 1500 readings. It is proposed that for long-term studies an alloy bar with hardened steel inserts should be used. The precision of measurements made with the gage was estimated from the large set of results.
Properties of Florida-Oolite Concrete
Authors: Collins JJ , Hsu TTC 
Published: February 2009

Abstract
An experimental study of the mechanical properties of Florida-oolite concrete and oolite aggregates is presented. The properties of Florida-oolite concrete determined were strength, modulus of elasticity, creep, and shrinkage. The properties determined for oolite aggregates were strength, modulus of elasticity, unit weight, specific gravity, absorption, and percentage of voids. The modulus of elasticity and the creep coefficient of concrete were found to be significantly less than the values predicted by the standard American Concrete Institute equations. In addition, the effects of prestress and heat curing on the properties of Florida-oolite concrete are discussed.
A Short-Time, High Temperature Mechanical Testing Facility
Authors: Marion RH 
Published: February 2009

Abstract
Design and performance details are given for a facility developed to obtain the mechanical properties of materials under high heating rate or transient temperature conditions and medium strain rates. The system uses self-resistance heating and is applicable to materials possessing electrical resistivities ranging from that of aluminum to that of graphite. Heating rates as high as 2000 K/s in graphite are attained under controlled conditions. Methods of measuring temperature and the effects of expected temperature distributions are discussed. A method for measuring strain during transient temperature conditions to 3000 K is described. Finally, results are presented for the stress-strain behavior of Type 316 stainless steel and ATJ(S) graphite obtained for heating times of few seconds.
Volume Fraction Determination in Cast Superalloys and Directionally Solidified Eutectic Alloys by a New Manual Point Count Practice
Authors: Andrews CW 
Published: February 2009

Abstract
Volume fraction of a constituent or phase was estimated in six specimens of conventional and directionally solidifed eutectic alloys in accordance with ASTM Recommended Practice for Determining Volume Fraction by Systematic Manual Point Count (E 562–76). Volume fractions determined ranged from 0.086 to 0.36, and with one exception the 95% relative confidence limits were approximately 10% of the determined volume fractions. Since the confidence limit of 10%, which had been arbitrarily chosen previously, was achieved in all but one case, this application of Recommended Practice E 562-76 was considered successful.
Load-Displacement Measurement and Work Determination in Three-Point Bend Tests of Notched or Precracked Specimens
Authors: Buzzard RJ , Fisher DM 
Published: February 2009

Abstract
Suggestions for testing of notched or cracked three-point bend specimens are presented that (1) correct displacement measurement errors resulting from misalignment between the load applicator and specimen; (2) account for coincidental strains not associated with the work of crack extension; (3) simplify record analysis and processing; and (4) extend displacement gage range without sacrifice of sensitivity or accuracy. These testing details are particularly applicable to procedures in which the crack extension force J1 is determined from the work done on the specimen.
A New Method of Test for Flexural Fatigue of Plastics
Authors: Gauvin R , Trotignon J-P 
Published: February 2009

Abstract
The flexural fatigue resistance of plastics as determined by ASTM Test for Flexural Fatigue of Plastics by Constant-Amplitude-of-Force (D 671-71) employs a technique that permits the testing of only a single specimen at a time. By contrast, the test based on constant-amplitude-of-deflection of the specimen proposed in this paper accommodates up to 16 specimens simultaneously, thereby substantially reducing the time required for the test. Constant-amplitude-of-deflection of the specimen is effected by rotation of its builtin end. Experimental data are presented that show that both methods give substantially comparable results for nylon 6/6 and acetal homopolymer. A brief description of the apparatus required for the new test is also given.
Threshold Corrosion Fatigue Crack Growth in Steels
Authors: Tu LKL , Seth BB 
Published: February 2009

AbstractThe threshold stress intensity factor range ΔKth of three steels was studied in air and steam. Constant load and constant crack opening displacement (COD) tests were conducted by using tension-tension sinusoidal wave function loading. The COD tests were controlled by a high frequency clip-on strain gage. Crack growth rate was measured by both optical and COD compliance techniques and verified by metallographic examination of the broken specimens. The ΔKth value was determined as the asymptote to the best-fit data below a crack growth rate of 2.5 × 10−8 cm/cycle. The ΔKth values were higher in steam than in air. Crack growth rates in air and steam generally crossover or merge in the range of 2.5 × 10−6 to 2.5 × 10−7 cm/cycle; below this range the growth rate is lower in steam than in air. The higher values in steam tests were explained by environmentally assisted crack branching and corrosion products formed at the crack tip after long-time testing at growth rates of less than one lattice spacing per cycle of loading.
Comparison of Equivalent Energy and Energy Per Unit Area (¯W/A) Data with Valid Fracture Toughness Data for Iron, Aluminum, and Titanium Alloys
Authors: Witzke WR , Stephens JR 
Published: February 2009

AbstractSmall specimens cut from large test specimens that had provided valid plane strain fracture toughness value KIc measurements were tested in slow bending at 25 and −196°C. The resulting load deflection curves were interpreted by the equivalent energy technique and two variations of the energy per unit area technique. The small specimen fracture toughness values resulting from all three methods produced good correlations with the valid, large specimen KIc values for the two test temperatures. For screening purposes the subsize specimen tests were considered to provide a relatively simple and reasonable estimate of the KIc of a material.
“PARS”—A Portable X-Ray Analyzer for Residual Stresses
Authors: James M , Cohen JB 
Published: February 2009

Abstract
The design, operation, and testing of a 7 to 11-kg hand-held X-ray device for measuring residual stresses are described. The instrument is based on a miniature X-ray tube and generator and a position-sensitive detector. No motion of the detector is needed to record a peak, eliminating the expensive and heavy gearing characteristic of a conventional diffractometer; the only mechanical motion during a measurement is one change of the orientation of the device to the object. An entirely portable instrument is therefore available for use in the plant or in the field. Tests are reported in which the stress is measured to ±40 MPa (± 6 ksi) or better in 4 to 20 s, depending on the specimen.
Measuring the Thermal Expansion of Solids with Strain Gages
Authors: Poore MW , Kesterson KF 
Published: February 2009

Abstract
A technique was developed to measure the thermal expansion of solids in the temperature range from −50 to 175°C. The technique uses strain gages to measure expansion and Type J (iron/constantan) thermocouples to measure temperature. Measurements were made on pure platinum and on copper and tungsten standard reference materials obtained from the National Bureau of Standards. Results were compared with the certified values of expansion. The maximum difference between measurements made in this study and the certified values was 0.26 × 10−6/°C for the mean coefficients and 0.40 × 10−6/°C for the instantaneous coefficients. The standard deviation of the measurements of the mean coefficients was 0.11 × 10−6/°C.
Comparison of Stress Corrosion Cracking Properties of Several Aircraft Structural Alloys
Authors: Ryder JT , Krupp WE , Pettit DE , Hoeppner DW 
Published: February 2009

Abstract
Sustained load subcritical flaw growth characteristics of five alloys of interest to aircraft designers were investigated. The aluminum alloy (2024-T851) and steel alloy (18Ni-maraging) were studied in 3.5% sodium chloride solution and high humidity air environments while two of the titanium alloys, Ti-6Al-4V (recrystallized annealed) and Ti-6A1-6V-2Sn (solution-treated and overaged), were also investigated in these environments plus sump tank water. The Ti-6Al-4V (beta) alloy was tested in 3.5% sodium chloride solution. Wide differences between the alloys were noted not only in their cracking rates but also in their responses to similar loads and environments. Specimen thickness was found to have an important effect on stress corrosion susceptibility of the titanium alloys. Many coupons of specific titanium alloys had significant subsurface crack growth without visible surface growth. For these alloys, no precise threshold for stress corrosion cracking could be defined.
An Indirect Tensile Test for Masonry Units
Authors: Borchelt JG , Brown RH 
Published: February 2009

Abstract
The failure of masonry in laboratory testing of walls and prisms and certain aspects of grouted construction is often the result of tensile splitting. These tensile stresses arise from differences in modulus of elasticity and Poisson's ratio between the masonry unit and mortar or grout. Since tensile splitting is so prevalent in masonry construction, a better means of evaluating the tensile strength of masonry units is needed. A splitting tensile test is proposed as a means of measuring tensile strength of masonry units. Splitting strength is compared to standard strength tests for 14 clay units and 14 concrete block units. Uniform failure modes and strengths support the adoption of a splitting test as a standard of masonry unit strength.
Measurement of Linear Expansion in Bricks Due to Freezing
Authors: Davison JI , Sereda PJ 
Published: February 2009

Abstract
A linear extensometer is described that can be used to measure expansions resulting from freezing in saturated porous inorganic building materials. Typical freezing curves illustrate reversible and irreversible expansions. The procedure may have application as a simple test method for assessing the durability of bricks or other porous inorganic building materials.
Use of Pelletized Slag in Concrete Masonry Units
Authors: Cotsworth RP 
Published: February 2009

Abstract
This paper contains a brief description of the slag pelletizer and the external pressures which led to its development. Pelletized expanded slag is an improved lightweight aggregate for the concrete masonry market. When compared to the earlier lightweight slag aggregates, the improvement manifests itself by a 20% reduction in cement contents for equal compressive strength masonry units. In addition, the water absorption of the masonry is reduced, the green strength is increased, and the visual properties of color and texture are improved. Research work and field trials indicate that the latent hydraulic property of the slag is available in the manufacture of block and brick masonry to further reduce added cementitious binder contents and thereby conserve energy. This can be accomplished by partially grinding the slag at a block plant to produce a self-cementing aggregate. It was also shown that slag fines may be partially replaced or extended by silica flour under some conditions of use.
Surface-Crack Shape Change in Bending Fatigue Using an Inexpensive Resonant Fatiguing Apparatus
Authors: Pierce WS , Shannon JL 
Published: February 2009

AbstractAn inexpensive device for producing surface cracks of controlled size and shape is described along with results of its use which show how the shape of the surface crack changes as it grows in bending fatigue from a variety of crack starter shapes. The growth pattern for any crack is uniquely defined by the crack starter configuration and appears to be independent of alloy. Shape changes are substantial and all growth curves tend toward a common growth curve. Circular cracks tend to become elliptical with an associated increase in stress intensity factor. This increase accelerates the crack growth rate and proximity to the critical flaw size. Through-cracks produced by the extension of a surface crack in a bending stress field will have length ten times the section thickness. The results demonstrate the necessity of taking into account changing crack shape in the calculation of structural life when bending is a significant component of the stress field.
Phase Extraction and Analysis in Superalloys—Second Summary of Investigations by ASTM Subcommittee E04.91
Authors: Donachie MJ 
Published: February 2009

Abstract
Additional phase identification procedures for superalloys have been evaluated. Reproducibility of results has been assessed and some tentative procedures for extraction of powdered metals and for the separation of extracted carbide and Laves phases have been evaluated. A definite procedure has been established to minimize errors in the identification of X-ray diffraction patterns of superalloy phases. The need for integrated use of analytical techniques to identify phases and characterize alloys by combined extraction, optical, electron optical, microprobe, and X-ray diffraction techniques has been recognized.
Displacement Coefficients Along the Inner Boundaries of Radially Cracked Ring Segments Subject to Forces and Couples
Authors: Gross B 
Published: February 2009

AbstractDisplacement results of plane boundary collocation analysis are given for various locations on the inner boundaries of radially cracked ring segments (C-shaped specimens) subject to two complementary types of loading. Results are presented for ratios of outer to inner radius Ro/Ri in the range of 1.1 to 2.5 and ratios in the range of 1.1 to 2.5 and ratios a/W in the range 0.1 to 0.8, where a is the crack length for a specimen of wall thickness W. By combination of these results the resultant displacement coefficient Δ or the corresponding influence coefficient E'BV/P can be obtained for any practical load line location of a pinloaded specimen.
Low Energy Impact Behavior of Composite Panels
Authors: Aleszka JC 
Published: February 2009

Abstract
Current results of an experimental study to determine the resistance of eight-ply AS/3501-5 graphite/epoxy, [±45 deg/0 deg/90 deg]s, to impact loadings incurred during ground handling and routine maintenance of aircraft are presented. The impact loading was simulated by dropping a 249-g (8 troy oz) cylindrical weight with a hemispherical head through a guide tube onto the panels. The configuration of the drop weight head was designed to simulate a blunt instrument while the total weight approximated that of a typical hand tool. This technique, which enabled up to 3.6 J (2.7 ft-lb) to be imparted to the panels, was found to be more versatile and informative than the conventional ball drop test.
Specimen response was monitored by strain gages attached to the drop weight and interfaced with an instrumentation system to provide load-time and energy-time records. These records were correlated with visible damage in the panels. The load and absorbed energy corresponding to incipient and full penetration damage were independent of impact velocity in the range studied.
Evaluation of Cushion Dynamic Properties by Impedance Measurements
Authors: Nassar EM 
Published: February 2009

Abstract
A method is proposed for the evaluation of cushions in dynamic environments. With the mechanical impedance technique the cushion properties are determined in terms of equivalent distributions of stiffness, damping, and mass parameters. Test results on a specific material show that these parameters may be considered of constant magnitude within limited ranges of frequencies and input levels. The equivalent cushion parameters are presented in dimensionless form as functions of the geometry and the input levels. The results warrant future tests at broader ranges of input and geometrical variables for further development of the method.