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定价： 345元 / 折扣价： 294 元

定价： 345元 / 折扣价： 294 元 加购物车

定价： 345元 / 折扣价： 294 元 加购物车

定价： 345元 / 折扣价： 294 元 加购物车

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定价： 345元 / 折扣价： 294 元 加购物车

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From these tests the relative expansive potential of soil-lime mixtures containing varying amounts of lime can be evaluated. From such an evaluation, the amount of lime required to reduce expansion to acceptable levels can be determined. The data can then be used for the design and specification requirements for subgrades and structural fills where expansive soils are encountered and it is desired to give a certain degree of expansion-shrinkage control to structure foundations and road subgrades. The tests will also show if the specific soils are amenable to lime stabilization.Note 2—The quality of the result produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection/and the like. Users of this standard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.1.1 These test methods provide procedures for conducting expansion, shrinkage, and uplift pressure tests on compacted soil-lime mixtures and can be used to determine the lime content required to achieve desired control of volume changes caused by increases or decreases of moisture.1.2 The tests can be used to determine (a) the magnitude of volume changes under varying load conditions, (b) the rate of volume change, and (c) the magnitude of pressure change as moisture changes of the soil-lime mixture take place. The permeability of soil-lime mixture can also, if desired, be determined at the various load conditions.Note 1—Changes in field conditions can have major effects on the expansion and shrinkage characteristics of expansive soils. Therefore, to the greatest extent possible, initial and anticipated future field conditions should be duplicated, particularly with respect to moisture and density.1.3 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026, D37401.3.1 The method used to specify how data are collected, calculated, or recorded in this standard is not directly related to the accuracy to which the data can be applied in design or other uses, or both. How one applies the results obtained using this standard is beyond its scope.1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

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5.1 Information concerning magnitude of compression and rate-of-consolidation of soil is essential in the design of earth structures and earth supported structures. The results of this test method may be used to analyze or estimate one-dimensional settlements, rates of settlement associated with the dissipation of excess pore-water pressure, and rates of fluid transport due to hydraulic gradients. This test method does not provide information concerning the rate of secondary compression.5.2 Strain Rate Effects: 5.2.1 It is recognized that the stress-strain results of consolidation tests are strain rate dependent. Strain rates are limited in this test method by specification of the acceptable magnitudes of the base excess pressure ratio during the loading phase. This specification provides comparable results to the 100 % consolidation (end of primary) compression behavior obtained using Test Method D2435.5.2.2 Field strain rates vary greatly with time, depth below the loaded area, and radial distance from the loaded area. Field strain rates during consolidation processes are generally much slower than laboratory strain rates and cannot be accurately determined or predicted. For these reasons, it is not practical to replicate the field strain rates with the laboratory test strain rate.5.3 Temperature Effects: 5.3.1 Temperature affects the rate parameters such as hydraulic conductivity and the coefficient of consolidation. The primary cause of temperature effects is due to the changes in pore fluid viscosity, but soil sensitivity may also be important. This test method provides results under room temperature conditions, corrections may be required to account for specific field conditions. Such corrections are beyond the scope of this test method. Special accommodation may be made to replicate field temperature conditions and still be in conformance with this test method.5.4 Saturation Effects: 5.4.1 This test method may not be used to measure the properties of partially saturated soils because the method requires the material to be back pressure saturated prior to consolidation.5.5 Test Interpretation Assumptions—The equations used in this test method are based on the following assumptions:5.5.1 The soil is saturated.5.5.2 The soil is homogeneous.5.5.3 The compressibility of the soil particles and water is negligible.5.5.4 Flow of pore water occurs only in the vertical direction.5.5.5 Darcy's law for flow through porous media applies.5.5.6 The ratio of soil hydraulic conductivity to compressibility is constant throughout the specimen during the time interval between individual reading sets.5.5.7 The compressibility of the base excess pressure measurement system is negligible compared to that of the soil.5.6 Theoretical Solutions: 5.6.1 Solutions for constant rate of strain consolidation are available for both linear and nonlinear soil models.5.6.1.1 The linear model assumes that the soil has a constant coefficient of volume compressibility (mv). These equations are presented in 13.4.5.6.1.2 The nonlinear model assumes that the soil has a constant compression index (Cc). These equations are presented in Appendix X1.NOTE 2: The base excess pressure measured at the boundary of the specimen is assumed equal to the maximum excess pore-water pressure in the specimen. The distribution of excess pore-water pressure throughout the specimen is unknown. Each model predicts a different distribution. As the magnitude of the base excess pressure increases, the difference between the two model predictions increases. At a base excess pressure ratio of 15 %, the difference in the average effective stress calculation between the two models is about 0.3 %.5.6.2 The equations for the linear case are used for this test method. This test method limits the time interval between readings and the maximum base excess pressure ratio to values that yield similar results when using either theory. However, it is more precise to use the model that most closely matches the shape to the compression curve.5.6.3 The nonlinear equations are presented in Appendix X1 and their use is not considered a non-conformance with this test method.5.6.4 The equations used in this test method apply only to steady state conditions. The transient strain distribution at the start of a loading or unloading phase is insignificant after the steady state factor (F) exceeds 0.4. Data corresponding to lower steady state factors are not used in this test method.5.7 This test method may be used to measure the compression behavior of free draining soils. For such materials, the base excess pressure will be zero and it will not be possible to compute the coefficient of consolidation or the hydraulic conductivity. In this case, the average effective axial stress is equal to the total axial stress and the results are independent of model.5.8 The procedures presented in this test method assume a high permeability porous disk is used in the base pressure measurement system. Use of a low permeability porous disk or high-air entry (>1 bar) disk will require modification of the equipment specifications and procedures. These modifications are beyond the scope of this test method and are not considered a non-conformance.NOTE 3: The quality of the results produced by application of this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.1.1 This test method is for the determination of the magnitude and rate-of-consolidation of saturated cohesive soils using continuous controlled-strain axial compression. The specimen is restrained laterally and drained axially to one surface. The axial force and base excess pressure are measured during the deformation process. Controlled strain compression is typically referred to as constant rate-of-strain (CRS) testing.1.2 This test method provides for the calculation of total and effective axial stresses, and axial strain from the measurement of axial force, axial deformation, chamber pressure, and base excess pressure. The effective stress is computed using steady state equations.1.3 This test method provides for the calculation of the coefficient of consolidation and the hydraulic conductivity throughout the loading process. These values are also based on steady state equations.1.4 This test method makes use of steady state equations resulting from a theory formulated under particular assumptions. Subsection 5.5 presents these assumptions.1.5 The behavior of cohesive soils is strain rate dependent and hence the results of a CRS test are sensitive to the imposed rate of strain. This test method imposes limits on the strain rate to provide comparable results to the incremental consolidation test (Test Method D2435).1.6 The determination of the rate and magnitude of consolidation of soil when it is subjected to incremental loading is covered by Test Method D2435.1.7 This test method applies to intact (Group C and Group D of Practice D4220), remolded, or laboratory reconstituted samples.1.8 This test method is most often used for materials of relatively low hydraulic conductivity that generate measurable excess base pressures. It may be used to measure the compression behavior of essentially free draining soils but will not provide a measure of the hydraulic conductivity or coefficient of consolidation.1.9 All recorded and calculated values shall conform to the guide for significant digits and rounding established in Practice D6026, unless superseded by this test method. The significant digits specified throughout this standard are based on the assumption that data will be collected over an axial stress range from 1% of the maximum stress to the maximum stress value.1.9.1 The procedures used to specify how data are collected/recorded and calculated in this standard are regarded as the industry standard. In addition, they are representative of the significant digits that should generally be retained. The procedures used do not consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the user’s objectives; and it is common practice to increase or reduce significant digits of reported data to be commensurate with these considerations. It is beyond the scope of this standard to consider significant digits used in analysis methods for engineering design.1.9.2 Measurements made to more significant digits or better sensitivity than specified in this standard shall not be regarded a non-conformance with this standard.1.10 Units—The values stated in either SI units or inch-pound units [given in brackets] are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard. Reporting of test results in units other than SI shall not be regarded as nonconformance with this standard.1.10.1 The gravitational system is used when working with inch-pound units. In this system, the pound (lbf) represents a unit of force (weight), while the unit for mass is slugs. The rationalized slug unit is not given, unless dynamic (F = ma) calculations are involved.1.10.2 It is common practice in the engineering/construction profession to concurrently use pounds to represent both a unit of mass (lbm) and of force (lbf). This implicitly combines two separate systems of units; that is, the absolute system and the gravitational system. It is scientifically undesirable to combine the use of two separate sets of inch-pound units within a single standard. As stated, this standard includes the gravitational system of inch-pound units and does not use/present the slug unit for mass. However, the use of balances or scales recording pounds of mass (lbm) or recording density in lbm/ft3 shall not be regarded as non-conformance with this standard.1.11 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.12 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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5.1 The most general method for obtaining CIE tristimulus values or, through their transformation, other coordinates for describing the colors of fluorescent objects is by the use of spectrometric data obtained under defined and controlled conditions of illumination and viewing. This practice describes the instrumental measurement requirements, calibration procedures, and material standards needed for measuring the total spectral radiance factors of fluorescent specimens illuminated by simulated daylight approximating CIE D65 and calculating total tristimulus values and total chromaticity coordinates for either the CIE 1931 or 1964 observers.5.2 The precise colorimetry of fluorescent specimens requires the spectral distribution of the instrument light source illuminating the specimen closely duplicate the colorimetric illuminant used for the calculation of tristimulus values, which is CIE D65 in this practice. The fundamental basis for this requirement follows from the defining property of a fluorescent specimen: instantaneous light emission resulting from electronic excitation by absorption of radiant energy (η) where the wavelengths of emission (λ) are as a rule longer than the excitation wavelengths (1).7 For a fluorescent specimen, the total spectral radiance factors used to calculate tristimulus values are the sum of two components – an ordinary reflectance factor, β(λ)S, and a fluorescence factor, β(η,λ)F : β(λ) = β(λ)S  + β(η,λ)F. Ordinary spectral reflectance factors are solely a function of the specimen's reflected radiance efficiency at the viewing wavelength (λ) and independent of the spectral distribution of the illumination. The values of the spectral fluorescent radiance factors at the viewing wavelength (λ) vary directly with the absolute spectral distribution of illumination within the excitation range (η), and consequently so will the total spectral radiance factors and derived colorimetric values. One-monochromator colorimetric spectrometers used in this practice are generally designed for the color measurement of ordinary (non-fluorescent) specimens and the precision with which they can measure the color of fluorescent specimens is directly dependent on how well the instrument illumination simulates CIE D65.5.3 CIE D65 is a virtual illuminant that numerically defines a standardized spectral illumination distribution for daylight and not a physical light source (2). There is no CIE recommendation for a standard source corresponding to CIE D65 nor is there a standardized method for rating the quality (or adequacy) of an instrument's simulation of CIE D65 for the general instrumental colorimetry of fluorescent specimens. The requirement that the instrument simulation of CIE D65 shall have a rating not worse than BB (CIELAB) as determined by the method of CIE Publication 51 has often been referenced. However, the method of CIE 51 is only suitable for ultraviolet-excited specimens evaluated for the CIE 1964 (10°) observer. The methods described in CIE 51 were developed for UV activated fluorescent whites and have not been proven to be applicable to visible-activated fluorescent specimens.NOTE 1: Aging of the instrument lamp will occur with normal usage resulting in changes in the spectral distribution and intensity of the illumination on the specimen over time. Measurement of the spectral distribution of the illumination at the sample port and evaluation of the adequacy of the CIE D65 simulation at regular intervals are recommended.5.4 Differences in the absolute spectral irradiance distribution on the specimen between instrument models can produce significant variation in the measured color values of fluorescent specimens and result in poor reproducibility (3). In order to reproduce adequately the spectral irradiance on the specimen required for maximum measurement reproducibility, it may be necessary for a single model of instrument to be specified for use by both buyer and seller.5.5 This practice is primarily for the instrumental color measurement of chromatic fluorescent specimens. While use of this practice for the color measurement of fluorescent whites is not precluded, other standards are more commonly used for measurement of these types of specimens (4, 5, 6) (see Test Methods D985, ISO 11475, ISO 2469, and TAPPI T 571).5.6 For geometrically sensitive fluorescent specimens angular tolerances on the axes and the angular aperture sizes must be well defined by the user to ensure adequate repeatability and reproducibility. Significant variation in measurement results for engineered surfaces and optical materials, for example retroreflective sheeting, can result from differences in the absolute axis angles of illumination and viewing and absolute size of the apertures between instruments (7). In order to replicate the measurement geometry, absolute angles and angular tolerances between instruments that is required for maximum measurement reproducibility, it may be necessary for a single model of instrument to be specified for use by both buyer and seller.NOTE 2: To ensure inter-instrument agreement in the measurement of specimens with intermediate gloss, for formulation, or retroreflective specimens, tight geometric tolerances are required of the instrument axis angles and the instrument aperture angles.5.7 Bidirectional (45:0 or 0:45) geometry is recommended for this practice.5.7.1 Hemispherical geometry using an integrating sphere is not recommended because of the spectral sphere error resulting from radiation emitted by the fluorescent specimen reflecting off the sphere wall and re-illuminating the specimen, thereby changing the spectral illuminance distribution on the specimen from that of the original instrument source (8).NOTE 3: The spectral sphere error associated with hemispherical geometry decreases as the ratio of the internal area of the sphere to the measurement area increases. When the spectral sphere error is negligible, results obtained using hemispherical geometry may for some specimens under specific measurement conditions approach those obtained using 45:0 geometry (9).5.8 This practice provides procedures for selecting the operating parameters of spectrometers used for providing data of the desired precision. It also provides for instrument calibration by means of artifact standards and selection of suitable specimens for obtaining precision in the measurements.5.9 Bispectral colorimetry using a bidirectional optical measuring system with a 45:0 or 0:45 illuminating and viewing geometry should be used when a high level of repeatability and reproducibility are required. The bispectral, or two-monochromator, method is the definitive method for the determination of the general radiation-transfer properties of fluorescent specimens. The bispectral method is accepted as the referee procedure for obtaining illuminant-independent photometric data on a fluorescent specimen that can be used to calculate its color for any desired illuminant and observer. The advantage of the bispectral method is that it avoids the inaccuracies associated with source simulation and various methods of approximation (10, 11) (see Practices E2152, E2153, and Test Method E2301).1.1 This practice applies to the instrumental color measurement of fluorescent specimens excited by near ultraviolet and visible radiation that results in fluorescent emission within the visible range. It is not intended for other types of photoluminescent materials such as phosphorescent, chemiluminescent, or electroluminescent, nor is this practice intended for the measurement of the fluorescent properties for chemical analysis.1.2 This practice describes the instrumental measurement requirements, calibration procedures, and material standards needed for the color measurement of fluorescent specimens when illuminated by simulated daylight approximating CIE Standard Illuminant D65 (CIE D65).1.3 This practice is limited in scope to colorimetric spectrometers providing continuous broadband polychromatic illumination of the specimen and employing only a viewing monochromator for analyzing the radiation leaving the specimen.1.4 This practice can be used for calculating total tristimulus values and total chromaticity coordinates for fluorescent colors in the CIE Color System for either the CIE 1931 Standard Colorimetric Observer or the CIE 1964 Supplementary Standard Colorimetric Observer.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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