| Laboratory and Field Evaluation of Polymeric Cavitation Erosion-Resistant Materials on Concrete. |
AUG 1976 |
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| Authors:
Tony B. Husbands; Leonard Pepper; ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MISS
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 | Fifteen polymeric coatings for protecting concrete against cavitation erosion were evaluated. Eight of these materials were found to be cavitation erosion resistant. Five of these eight materials were polyurethane sheet materials: the other three were a liquid-applied polyurethane, a neoprene sheet, and a liquid-applied neoprene. The materials were evaluated by coating mortar specimens with the materials and determining the adhesive bond strength. Those materials which were bonded successfully to the ... |
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| Development of In-House Capabilities for Determination of Quality of Water and Sediments. |
MAR 1974 |
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| Authors:
Clara F. Derrington; Leonard Pepper; Dennis L. Bean; ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MISS
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| A laboratory at the U. S. Army Engineer Waterways Experiment Station has been equipped with the proper apparatus, glassware, and chemicals so that water, soils, and sediments may be analyzed for pesticides, heavy metals, bacteria, biostimultants, and related constituents as needed in multiple samples. Two gas chromatographs--one for use in analyzing chlorinated hydrocarbon pesticides and one for organophosphate pesticides--are available for pesticide analyses. Capabilities have been established for analyzing routinely ... |
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| Analyses of Check-Test Results of Pozzolan Samples. |
FEB 1973 |
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| Authors:
Leonard Pepper; ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MISS
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| A program of periodic duplicate sampling and check testing of fly ash and other pozzolans was instituted to obtain information that may provide a basis for improving the specifications for and the methods of sampling and testing fly ash and other pozzolans. |
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| Effects of Water on Epoxy-Resin Systems. |
SEP 1971 |
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| Authors:
Tony B. Husbands; Clara F. Derrington; Leonard Pepper; ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MISS
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| The effect of continuous immersion in water on the tensile strength, tensile elongation, tensile modulus, flexural strength, flexural strain, and bond strength of five different epoxy-resin systems was evaluated. The water absorption of the five systems was also obtained. One of the systems will meet Federal requirements for epoxy resins and another contains the same system but includes sand as a filler. All of the physical properties of these two ... |
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| Survey of Applications of Epoxy Resins for Civil Works Projects. |
JUL 1971 |
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| Authors:
Clara F. Derrington; Leonard Pepper; ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MISS
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| This report includes a summary of the uses and types of applications, the procedures involved, and the performance of epoxy resins used for civil works projects since 1959; and a guide for recommended practice for use of epoxy compounds with concrete. A TOTAL OF 80 APPLICATIONS OF EPOXY RESINS ARE DISCUSSED, WITH THE TYPE AND NUMBER OF APPLICATIONS AS FOLLOWS: bonding fresh to hardened concrete, 33; patching and filling and ... |
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| PRECISION OF QUARTZ CRYSTAL AND MERCURY DIFFERENTIAL THERMOMETERS IN HEAT-OF-HYDRATION TEST. |
JUL 1969 |
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| Authors:
Leonard Pepper; ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MISS
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| The precision of a quartz crystal thermometer was directly compared with that of a mercury differential thermometer in the determination of the heat of solution of a type II low-heat portland cement and a hardened paste made with the cement. The standard calorimeter apparatus was altered to permit (a) the insertion of one crystal probe into the calorimeter and a second crystal probe into the thermal jacket of the calorimeter ... |
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| Cooperative Investigation of Acceptance Test Methods for Chemical Analysis of Pozzolans for Mahor Oxides, |
AUG 1964 |
30 pages |
| Authors:
Leonard Pepper; ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MISS
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 | The procedure specified in acceptance testing of pozzolans for chemical analysis for major oxides is more involved and most costly than the procedure used for such analyses in the acceptance testing of portland cement. In order to investigate the simplification of the procedure for testing pozzolans, four pozzolans were evaluated. The methods used were: The prescribed method, which involves fusing the sample and then determining the major oxides by the ... |
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| EVALUATION OF ALUMINUM-COATED WIRES AS REINFORCEMENT FOR ARTICULATED CONCRETE MATTRESSES; SUPPLEMENTARY COMPARATIVE TESTS OF STAINLESS AND COPPER-CLAD STEEL WIRES. |
MAY 1964 |
28 pages |
| Authors:
Leonard Pepper; ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MISS
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| Tests were conducted to determine galvanic effect between stainless steel and copperweld wires, and effect on tensile strength of copperweld wire of pinholes and the corrosion in pinholes. In the galvanic-effect tests, stainless-steel and copperweld-wire specimens were tied together and exposed (completely immersed, partially immersed, or alternately immersed and dried) to either 5000 ppm NaCl (pH 7) or dilute H2SO4 buffered at pH 5, maintained at 100F. Degree of corrosion ... |
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| Evaluation of Asphaltic Waterproofing Systems for Concrete Structures, |
JAN 1964 |
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| Authors:
Leonard Pepper; ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MISS
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| Two asphaltic waterproofing systems, one hot-applied and the other cold-applied, were evaluated for adequacy of performance at several hydrostatic pressures. The economic benefits and ease of application of the cold-applied system warranted a study of the adequacy of the system in comparison with the hot-applied system. The hot-applied system was tested for permeability. The cold-applied system was tested for permeability, adhesion to concrete, and water-vapor transmission. (Author) |
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| INFLUENCE OF ALKALI CONTENT OF FLY ASH ON EFFECTIVENESS IN PREVENTING EXPANSION OF CONCRETE. |
JUN 1963 |
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| Authors:
Leonard Pepper; ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MISS
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| Eight mixtures containing various ratios of high- or low-alkali fly ash and cement, and two control mixtures were made to determine the influence of the alkali content of fly ash on its effectiveness in preventing expansion of mortar bars made from the mixtures. Mortar bars were cast and their lengths measured at 2, 14, and 28 days, 6 months, and 1 year. Data from this and a previous investigation using ... |
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| Investigation of Nonmetallic Waterstops. Evaluation of the Effect-of-Alkalies and Accelerated Extraction Tests. Report 2. |
MAR 1961 |
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| Authors:
Leonard Pepper; ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MISS
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| Nineteen nonmetallic waterstop materials, consisting of 10 standard or cold-weather PVC, two polyethylenes, and seven natural or synthetic rubbers, were subjected to the accelerated extraction and effect-of- alkalies tests. The accelerated extraction test did not affect the tensile strength of the standard-grade PVC, but did affect the tensile strength of all the other materials tested. The accelerated extraction test affected the ultimate elongation of all the materials tested. The changes ... |
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| Effectiveness of Mineral Admixtures in Preventing Execessive Expansion of Concrete Due to Alkali-Aggregate Reaction. |
JUL 1958 |
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| Authors:
Alan D. Buck ; B. J. Houston ; Leonard Pepper; ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MS
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| Twenty materials, representing eight different classes of mineral admixtures, were evaluated, using both chemical and mortar-bar test methods, for their effectiveness in preventing excessive expansion of concrete due to alkali-aggregate reaction. The criteria of the chemical tests are examined, and the test results were compared with the mortar-bar test results. All results were compared with those obtained by two other laboratories. It was found that the chemical tests cannot be ... |
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| TESTS OF MEMBRANE-FORMING COMPOUNDS FOR CURING CONCRETE. |
JUN 1954 |
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| Authors:
Leonard Pepper; Clara F. Derrington; ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MISS
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| The report discusses the investigation of membrane-forming compounds for curing concrete which was undertaken for the purpose of developing an acceptance specification, and appropriate test methods for evaluating the suitability of such materials for curing concrete. The report reviews briefly the considerations involved in establishment of the testing procedures, their nature, and some of the precautions that must be observed in their performance. (Author) |
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Reports by Author
