bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Comparison of Automated Versus Manual Measurement of Total Elongation-Tension Testing
Authors: Scherrer DK 
Published: March 2009

A study was conducted to compare two methods of determining the total percent elongation from standard tension tests. For each test, total percent elongation was measured by two methods: the conventional manually “measured” method where the broken specimen halves are fitted back together after the test, and the automated “extensometer” method where elongation to fracture is determined by an extensometer that is left on the specimen up to the moment of fracture.
Comparison of “measured” and “extensometer” elongation results reveals excellent agreement between the two methods. The difference between the two elongation values is generally less than 1% elongation, with the measured value normally being higher.
A model was developed that could be used to predict the “measured” elongation from the “extensometer” elongation to within 1% to 1.5% of the actual “measured” value.
A Technique for Determining Yield Point Elongation
Authors: Young JJ 
Published: March 2009

A method capable of calculating the Yield Point Elongation (YPE) in an automated testing system was investigated and an algorithm for determining YPE was developed. One problem that had to be resolved before a YPE algorithm could be developed was that the definition of YPE as presented in ASTM E 6, Definitions of Terms Relating to Methods of Mechanical Testing, was based upon an informal definition of discontinuous yielding. Automation of the YPE calculation required a formal definition. Discontinuous yielding was formalized to be the region over which the stress-strain diagram exhibited points of inflection (i.e., points where the second derivative of the stress-strain diagram is equal to zero). The definition of YPE then became “the difference between the elongation at the yield point and the last inflection point.”
Given the formalized definition of discontinuous yielding, it became necessary to develop an algorithm for the calculation of first and second derivatives. This investigation centered on the use of difference equations and the use of third order polynomial approximations (cubic splines) to the sampled data. Since derivative calculations inherently increase any noise that is present in the system, the susceptibility of each of these algorithms to noise was examined by impressing a gaussian noise source onto a sinusoid. The cubic spline method was selected since it caused the least amount of noise amplification. The amount of noise rejected by the cubic spline increased with the size of the region that was fitted. However, this caused an increase in the error of the polynomial approximation. When applied to actual test data, the error in the polynomial approximation resulted in increased error in the location of the inflection points. This put a limit on the amount of noise that could be rejected.
Since the noise could not be completely eliminated, false inflection points were exhibited.Therefore it was necessary to identify and ignore these false inflections. This was accomplished by calculating the slopes at successive inflection points and comparing them to the slope of the line intersecting the origin and the point of ultimate load (i.e., the point at which the maximum load occurred after lower yield). If the slope at the inflection point was within certain bounds, specified as a percentage of the ultimate load line slope, then the inflection point was considered to be valid; otherwise, it was rejected. Once the false inflection points were eliminated, the location of the last inflection was identified and the yield point elongation was calculated.
Accelerated Test for Determining Microbiological-Influenced Corrosion Resistance of Aluminum Alloys
Authors: Rosales BM , Ayllon ES , Leiro MC 
Published: March 2009

This paper summarizes the experience developed during various research work performed using 2024-T3, 7075-T6, and 7005-T6 aeronautical aluminum alloys in different natural and laboratory aqueous media.
The effect on corrosion of the components of a mineral aqueous nutrient medium that supports fungus proliferation was evaluated using an electrochemical technique. Through anodic and cathodic potentiokinetic polarizations, it was possible to determine the susceptibility, type, and relative amount of corrosion damage to the alloys in the medium as well as changes in the medium caused by the metabolic consumption of its components.
The microbiological-influenced corrosion (MIC) effects associated with metallurgical characteristics of the alloys, such as the thermomechanical treatments, secondary phases, and surface roughness, were also determined by means of the polarization tests. These tests are very useful accelerated techniques to evaluate the susceptibility of an aluminum alloy to localized attack in a given environment. They also provide information concerning the morphology and magnitude of the damage.
Design and Testing to Reduce Efflorescence Potential in New Brick Masonry Walls
Authors: Chin IR , Petry L 
Published: March 2009

Efflorescence is a deposit of substances leached from the masonry either onto the surface or into the pores of brick masonry walls. These deposits may be the substances themselves or secondary reaction products of them with the atmosphere. Investigations of efflorescence on brick masonry walls on dozens of structures throughout the United States by the authors and their colleagues have revealed that the efflorescence on approximately 50 percent of the 43 samples studied consists of water soluble sulfate compounds and that the efflorescence on approximately 40 percent of the samples studied consist of calcium carbonate (carbonated calcium hydroxide) that is not soluble in water. Whenever sulfate compounds are predominant in efflorescence on brick masonry, the source of the efflorescence is usually the brick. Calcium carbonate “efflorescence” originates from the mortar. These data strongly suggest that water soluble efflorescence on brick masonry is most likely a sulfate compound which originated from the brick.
To reduce the potential for efflorescence development in brick masonry walls, the bricks manufactured for a specific building should be tested in accordance with ASTM C 67, Method of Sampling and Testing Brick and Structural Clay Tile. In addition, they should be chemically analyzed for water-soluble constituents to assess the efflorescence potential of the brick.
The potential for efflorescence development in brick masonry walls can also be reduced through the use of drainage type walls with a proper flashing and weep system and through the use of good construction practices and proper material selection.
The Influence of Horizontal Reinforcement on the Shear Performance of Concrete Masonry Walls
Authors: Foltz S , Yancey CWC 
Published: March 2009

This report documents one experimental investigation which is part of an overall program of research on the properties of concrete masonry. The primary objective of this testing was to evaluate the effect of the quantity and the distribution of horizontal reinforcement on masonry walls under cyclic in-plane loading which fail by a shear mode (primarily diagonal cracking). The ten wall specimens in the current investigation were subjected to an average of over forty loading cycles. Nine to eighteen of these cycles were applied before yield and loss of load capacity. The walls were subjected to cycles of increasing displacements separated by “degradation cycles.”
All ten walls were seven courses high (56 inches or 1.42 m) and three blocks wide (48 inches or 1.22 m) and made from similar concrete block and mortar. The concrete blocks used were hollow block having a unit compressive strength of 1900 psi (13.1 MPa) based on the gross area. The mortar was proportioned as type S. Reinforcement was provided by two types of steel. Rebar steel was placed in grouted bond beams. As an investigation of an alternative method, 9-gage ladder type reinforcement was placed in the bed joint of some walls. Axial load was 39.3 kips (174.9 kN), resulting in a uniformly distributed pressure on the net cross section of 200 psi (1.38 MPa).
Interim Report on a Study to Determine Lap Splice Requirements for Reinforced Masonry
Authors: Schuller MP , Hammons MI , Atkinson RH 
Published: March 2009

An investigation of parameters which affect the strength of lap splices within reinforced masonry is currently being conducted as part of the U.S. Army Corps of Engineers program for Construction Productivity Advancement Research (CPAR). Results from the first phase of the investigation complement existing data regarding lap splices in reinforced masonry and provide a comprehensive review of the effects of masonry unit width, masonry unit type, reinforcing bar diameter, and lap length on both the strength and monotonic behavior of lap splices in masonry.
Results of the experimental investigation have shown that the linear relationship used by current working stress masonry design standards does not accurately describe ultimate splice capacity in some cases. An alternate model, adopted for use in the proposed Masonry Limit States Design Standard, provides a more rational approach to the determination of lap splice lengths in masonry. This method considers reinforcing bar diameter and yield strength, grout tensile strength, and masonry wall thickness when determining splice length. Experimental results are in good agreement with values provided by this analysis and have been used to further verify the applicability of the model.
Flexural Bond Strength of Concrete Masonry Prisms Using Masonry Cement Mortars
Authors: Melander JM , Ghosh SK , Dubovoy VS , Hedstrom EG , Klingner RE 
Published: March 2009

Results of a test program to determine flexural bond strengths associated with Type M, S, and N portland cement/lime mortars under controlled test conditions were reported in the February 1991 issue of The Masonry Society Journal. Subsequent to that investigation on portland cement/lime mortars, similar tests were performed using masonry cement mortars. In these tests,flexural bond strengths were determined for Type S and Type N masonry cement mortars, using special standard concrete brick. The laboratory tests were designed to control materials, prism fabrication, curing, and testing. The mortar materials included Type S and Type N single-bag masonry cements and standard Ottawa sand. Results of tests conducted at Construction Technology Laboratories, Inc. (CTL), at the research laboratory of the National Concrete Masonry Association (NCMA), and at the University of Texas at Austin (UTA) are summarized and discussed in this paper.
For each of the mortar mixes, the initial flow, water retention, air content, and cube compressive strengths at 7 and 28 days were determined. Six prisms,each consisting of six standard concrete brick and five mortar joints, were fabricated and tested for flexural bond strength at 28 days according to ASTM C 1072-86, Method for Measurement of Masonry Flexural Bond Strength. Tests of some mortars were duplicated in different laboratories. The mean, standard deviation, and coefficient of variation were calculated for the 30 joints tested in each test series. Results provide a general indication of the flexural bond strength of masonry cement mortars under the test conditions of the program.
Influence of Aggregate Microstructure on the Volume Stability of Lightweight Concrete Masonry
Authors: Bremner TW , Rae D 
Published: March 2009

The microstructure of four types of manufactured lightweight aggregate was studied using scanning electron microscopy and the results were used to provide insight into the dimensional stability of concretes made from these aggregates. Dimensional stability was determined according to the Test Method for Length Change of Hardened Hydraulic-Cement Mortar and Concrete (ASTM C 157) as modified by the procedures covered in the Specification for Lightweight Aggregates for Concrete Masonry Units (ASTM C 331).
Aggregate types studied were rotary kiln produced expanded shale, sintered fly ash, palletized cold bonded fly ash and expanded glass. Scanning electron microscopy revealed the nature of the aggregate pore structure and the extent to which the vesicular structure, typical of most lightweight aggregates, is interconnected. When used in concrete, the three aggregates produced at high temperature met the ASTM C 331 shrinkage requirements while the one made by cold-bonding did not. After 100 days of drying the aggregates were immersed in a lime saturated water for an additional 251 days, followed by air drying during which length measurements were taken periodically. The microstructure was shown to have a pronounced effect on the volume stability of the aggregate.
Evaluation of ASTM E 514-90 Water Penetration and Leakage Test to Assess Performance of Integral Water Repellent Admixtures
Authors: Chin D , Gates RE 
Published: March 2009

Integral water repellent admixtures have played an important role in improving performance of architectural concrete block by minimizing penetration of water into the concrete block wall. The ASTM E 514-90 Test Method for Water Penetration and Leakage through Masonry is commonly used to measure the performance of unit masonry subjected to a 4 hour simulated wind-driven rain. A laboratory test program was conducted to evaluate the effectiveness of the ASTM E 514-90 test method in determining performance of walls constructed with materials which contain integral water repellent admixtures, to determine the effect of extending the test period from 4 hours up to 72 hours and to compare the performance of four different integral water repellent admixtures.
Suggestions are made regarding potential modifications that can be made to the E 514-90 test in order to effectively evaluate the performance of walls constructed with concrete masonry units and mortar which contain an integral water repellent admixture.
Quantification of Masonry Deterioration Through Statistical Modelling -- A Case Study
Authors: Whitlock AR , Fairley WB , Izenman AJ 
Published: March 2009

Structures of all types experience physical damage due to numerous conditions or circumstances. Errors in design, defective materials, improper construction, or poor workmanship can lead to deterioration or failure of building structures or components. Natural aging processes, chemical attack, or the effects of natural disasters create damage. Determining the precise causes or mechanisms responsible for the condition is important and the procedures for doing so have been well researched and published. Also important, however, is quantifying the amount of damage. Quantification is important so that accurate estimates of repair costs can be established, budgeting for the repairs, and for scheduling.
This paper presents a case study concerning a condition survey of five nearly identical buildings constructed of fired clay masonry. Specifically, the surveying and estimation of spalled masonry units is discussed. In this case study, total damage is first assessed by means of two different and independent observational procedures, one of which suffers from incomplete data collection. Missing data are estimated using Poisson log-linear regression modelling of the relationship between damage assessments and a number of qualitative factors. The resulting two sets of predicted total damage estimates are then obtained through calibration techniques.
Evaluation of Injectable Cementitious Grouts for Repair and Retrofit of Masonry
Authors: Atkinson RH , Schuller MP 
Published: March 2009

Injection of grout into cracks may be used as a form of repair following a damaging event or as a means to strengthen multi-wythe masonry, enhancing composite action between the wythes. An experimental program has been conducted to evaluate grouting procedures, the suitability of different types of cementitious grouts for injection, and the effect of grout injection on structural behavior.
Over 30 separate mixes utilizing various cementitious components, aggregates, admixtures and different water/cement ratios have been evaluated. A standardized series of evaluation tests have been used to compare injectability, mix stability, and grout properties for each of the mixes. These grouts possess properties similar to the masonry being repaired, and would be available for widespread use as a material for masonry repair. An additional contribution of this research has been the application of nondestructive techniques as a means of measuring quality of the injection process.
Failures of Interior Masonry Halls Subjected to Lateral Air Pressure
Authors: Kaskel BS , Romero RC 
Published: March 2009

Interior masonry partition walls in three different buildings were found to fail when subjected to significant unanticipated lateral loads due to air pressures. These walls were built around the 1970's and were empirically designed. Governing codes then, as now, commonly required that an interior partition be designed to sustain a lateral load of 5 Ibs. per sq ft (24.4 kg per sq meter). In one case, loads of 15 Ibs. per sq ft (73.2 kg per sq meter) were recorded by instrumentation of the walls.
The investigation and its findings are presented for each of the three case studies. Lessons learned from these examples about lateral loads and the design of masonry partition walls are presented to assist in future designs. This paper also reviews empirical design and minimum design load provisions in current codes and standards to examine whether they accurately account for such load cases.
Urethane Foam Injection as a Method of Remedial Repair for Masonry Cavity Walls
Authors: Kenney RJ , Piper RS 
Published: March 2009

In 1981, various tests were performed by the authors to determine if the injection of a urethane foam into the cavity of a typical cavity wall system would substantially alter the properties of the wall system and, more important, if the normal adhesive properties of the polyurethane would bond the veneer outer leaf sufficiently to prevent loosening of the outer leaf during periods of excessive movement. Tests included both laboratory tests on cavity wall panels and samples taken from the wall systems of projects where the cavity walls were repaired using the foam injection method.
Evaluations were made as to the practicality of the repair method and long-term durability of the urethane foam. One building approximately 21 years old, six buildings 5 to 9 years old, and two buildings 1 to 2 years old were monitored to see if the foam material injected into the cavity could have a long-term effect on dimensional stability.
The increased structural capacity of similar cavity wall systems when filled with foam to form a composite structure was substantial. The increase in bond and the bonding of each veneer unit to the substrate was also a benefit of this repair method.
This repair method offers a relatively inexpensive method of remedial repair of cavity wall systems, and can have wider applications particularly in areas prone to earthquake.
New Trenching Method Using Synthetic Bio-Polymers
Authors: Tallard GR 
Published: March 2009

For the first time, a radical departure from solidly established concepts and practices based on the use of bentonite for trenching under slurry, is proving itself as a viable alternative. It is even more so in this age of acute environmental sensitivity. The role played by polymers, and in particular a synthetic biodegradable polymer, are taking an increasing role in geotechnical construction: cohesionless sands can be cored with 100% recovery and small and large diameter soft ground tunnels are being bored with greater ease. Of interest to the field of slurry trenched excavations is the new ability to excavate under slurry, be it for continuous deep french drain or for a panelized reinforced concrete diaphragm wall, using a same and totally new kind of slurry. This slurry is a solution of polymers combined with either natural fines or added colloids. Since the slurry is naturally biodegradable, it can be used in all situations. The biodegradation can be deferred by inhibitors and with pH control while regulating it according to needs.
Leachate collection or recharge french drains installed under slurry are presented from the conceptual and QC perspectives. Since most structural slurry wall projects are in urban areas, where working with clay muds is problematic for many reasons, the writer examines the advantages of going from bentonite to polymer slurries. The limitations of the new technology are also discussed.
State of the Art in Bio-Polymer Drain Construction
Authors: Day SR , Ryan CR 
Published: March 2009

A common feature of civil engineering design is the “french drain,” a trench intended to intercept and collect groundwater and transfer it laterally to a sump. The environmental marketplace has created a larger demand for these drains for the purpose of the collection of contaminated groundwater. Traditional construction methods that use trench boxes or shoring, sometimes in combination with dewatering systems, present a number of problems, particularly if the trenches have depths in excess of about five meters.
The Bio-Polymer Slurry Drain (BP Drain) has provided a new method for constructing deep drains that eliminates shoring and dewatering. It does not require a wide excavation, reducing spoil disposal and does not require trench entry by workers, improving safety.
The system uses basic slurry trench technology but, instead of bentonite clay slurry, a guar-gum based slurry is used to maintain the open trench. Once the trench is dug to full depth, it is backfilled with a pervious material such as gravel. Wells can be inserted, pipe laterals can be placed and filter fabric inserted, all under slurry. When the trench is filled, the slurry is chemically and biologically “broken”, allowing the slot to collect water.
This paper reviews the current practice as illustrated by these case studies: a collection trench for oil, another for a chemical containment, and a drain constructed inside a slurry wall at a landfill site. The authors believe that this methodology will be subject to wide application once all of its features and advantages are fully realized.
Aquatic Test Systems for Studying the Fate of Xenobiotic Compounds
Authors: Cripe CR , Pritchard PH 
Published: March 2009

A variety of test systems, including microcosms, have been developed to provide information on the environmental fate of test compounds in aquatic ecosystems. As the overall strategy for development of tests has been less than logical and only vaguely chronological, we believe that some degree of categorization and guidance in the application of these test systems is appropriate. Our approach is based on four criteria: environmental inocula, sediment, generation of degradation rates, and intact water/sediment cores. Test systems either (1) provide basic biodegradability/rate information (Screening Tests) or (2) answer research questions about biodegradation rates and their controlling factors in the environment (Investigative Tests). Examples of each system type are cited with their respective advantages and disadvantages.
Criteria are suggested for selection of test systems with emphasis on the simplest system that can provide the most relevant and necessary information. Shake-flask tests are recommended for degradation rate information and assessment of significance of environmental factors on degradation. Intact core microcosm systems are useful to study a limited number of processes that cannot be examined in shake-flasks and, with a mathematical model, to verify biodegradation rates obtained from simpler test systems using conditions more reflective of natural conditions.