【AS澳大利亚标准】AS 1141.14-2007 Methods for sampling and testing aggregates - Particle shape. by proportional caliper.doc

australian standard1 as 1141.142007.auaccessed by university of south australia on 06 oct 2007as 1141.142007methods for sampling and testing aggregatesmethod 14: particle shape, by proportional caliper1 scopethis standard sets out a method to determine the proportion of flat particles, elongated particles and, flat and elongated particles found in those fractions of a coarse aggregate retained on a 9.50 mm test sieve, using a proportional caliper.note: for information on uncertainty of measurement, see appendix a.2 normative referencesthe following referenced documents are indispensable for the application of this document: as1141methods for sampling and testing aggregates1141.1method 1: definitions1141.2method 2: basic testing equipment1152specification for test sieves3 definitionsfor the purpose of this standard, the definitions given in as 1141.1 and the ones below apply.3.1 caliper ratiothe caliper ratio can be either 2:1 or 3:1, as required by the technical specifications.3.2 elongated particlean elongated particle is one having a ratio of length (l) to width (w) greater than the caliper ratio adopted.3.3 flat particlea flat particle is one having a ratio of width (w) to thickness (t) greater than the caliper ratio adopted.3.4 flat and elongated particlea flat and elongated particle is one having a ratio of length (l) to width (w) and a ratio of width (w) to thickness (t) greater than the caliper ratio adopted.3.5 length, width and thicknessthe length (l), width (w), and thickness (t) are, respectively, the greatest, intermediate and least dimensions of any particle, as measured along mutually perpendicular directions, that is, they are the principal dimensions of the circumscribing rectangular prism.accessed by university of south australia on 06 oct 2007the standard is downloaded from standard sharingas 1141.142007 23.6 proportion of elongated particlesthe proportion of elongated particles is the percentage of elongated, and flat and elongated particles.3.7 proportion of flat particlesthe proportion of flat particles is the percentage of flat, and flat and elongated particles in the aggregate, retained on 9.50 mm test sieve, determined by summing the weighted percentages.3.8 proportion of misshapen particlesthe proportion of misshapen particles is the percentage of flat, elongated and flat and elongated particles in the size fraction measured, determined by summing the weighted percentages.3.9 size fractiona size fraction is that portion of the sample retained between two of the successive sieves specified for the test.3.10 weighted percentagethe weighted percentage is the percentage of a type of misshapen particle in a particular size fraction multiplied by the amount of material in that size fraction (expressed as a percentage of all the material measured) and divided by one hundred.4 apparatusthe following apparatus, complying with the relevant provisions of as 1141.2, are required:(a) balanceof adequate capacity, with a limit of performance not exceeding 5 g.(b) caliperproportional caliper capable of ratios 2:1 or 3:1, made of steel as shown infigure 1. the fixed posts shall be suitably hardened.(c) ovena thermostatically controlled oven to operate at a temperature of 105c to110c.note: material may be dried to constant mass using other methods such as microwave ovens, infra-red lights or hotplates, provided tests have shown that these techniques do not disrupt or weaken particles to the extent that changes occur in the property being measured. the determination of constant mass will have to be such that, after further periods of drying using the selected method, the loss in mass does not exceed 1% of the total losses of moisture.(d) sample divider.(e) sievescomplying with as 1152 as required, i.e., 53.0 mm, 37.5 mm, 26.5 mm,19.0 mm, 13.2 mm, and 9.50 mm.5 test portionthe test portion shall be of a size that will yield not less than 100 particles of each size fraction larger than 9.50 mm present in an amount of not less than 10% of the sample.6 test procedurethe procedure shall be as follows:(a) dry the test portion at 105c to 110c to constant mass.note: see note under clause 4(c). standards a.auaccessed by university of south australia on 06 oct 20073 as 1141.142007(b) separate the test portion into size fractions on the following sieves: (i)53.0 mm.(ii) 37.5 mm. (iii) 26.5 mm. (iv)19.0 mm. (v)13.2 mm. (vi) 9.50 mm.determine the mass of each size fraction and calculate the grading of the aggregate as received, on a percentage passing basis.(c) calculate the percentages retained in each size fraction (percentages b in table 1).(d) discard the fraction passing the 9.50 mm test sieve. if any size fraction constitutes less than 10% of the aggregate as received, it shall be excluded from shape measurement and from subsequent calculations.(e) recalculate the proportion retained in each remaining size fraction as a percentage of the total amount of the remaining size fractions, that is, those to be measured (percentage c).(f) in any size fraction (present in the amount of 10% or more of the sample as received), if there are considerably more than 100 particles present, reduce the amount of material by sample division to obtain at least 100 particles to be measured. determine the mass of these particles (mass d) and record the number of particles present.(g)test each of the particles in each of the size fractions prepared for measurement, using the proportional caliper set at the caliper ratio adopted, as follows:(i) test for flatness set the largest opening equal to the width of the particle. if the thickness of the particle can be placed within the smaller opening, the particle is deemed to be flat.(ii) test for elongation set the large opening equal to the length of the particle. if the width of the particle can be placed within the smaller opening, the particle is deemed to be elongated.(h) sort the particles in each of the size fractions being measured into the following four types (see note 2):(i) flat.(ii) elongated.(iii) flat and elongated.(iv)neither flat nor elongated.determine the mass of each of types (i), (ii) and (iii), (masses e, f and grespectively).notes:1material that is beyond the capacity of the proportional caliper will have to be measured by other means.2if it is desired only to determine the proportion of flat particles, the test procedure can be varied by sorting into two groups only, that is, those which comply with the particular shape definition and those which do not. standards a.auaccessed by university of south australia on 06 oct 2007the standard is downloaded from standard sharingas 1141.142007 47 calculationsthe results of the test shall be calculated and reported to determine the percentage of misshapen particles from the weighted percentages of flat, elongated, and flat and elongated particles.select the ratio used for calculation.weighted percentages shall be calculated (percentages h, j, k) to the nearest 0.1%. the total percentage (l) of misshapen particles shall be expressed to the nearest 1%. table 1 shows an example of the calculation procedure.8 reportthe following shall be reported:(a) total percentage of misshapen particles to the nearest 1%.(b) if required, the flat, elongated, and, flat and elongated particles to the nearest 0.1%. (c)caliper ratio used.(d) reference to this standard, as 1141.14. standards a.au standards australiaas 1141.1420075accessed by university of south australia on 06 oct 2007table 1examples of calculation to determine percentage of misshapen particlesgradingsize fraction testsorting resultsweighted percentagesieveaperturemm percent passingpercent retained in each size fractionmassgnumber ofparticlesflatelongatedflat andelongatedflatelongatedflat andelongatedmisshapenasreceivedcalculated on retained9.50 mmgggbc =adefge c h =df c j =dg c k =dl = h + j + k53.037.526.519.013.29.5010098916020152*7*31405*43.756.3295.1168.210214815.617.87.710.86.0totalsa = 71100total percent misshapen19b 100* size fractions indicated thus are less than 10% of the sample as received and are not included in a.as 1141.142007 6 standards a.auposition of wing nut s wing ing arm fix ed post base 365 75 fix ed post plan sho wing swing ing arm set f or 3 : 1 ratio 6.3 (a) arrangement (b) fix ed post 1065 25 tw o holes ,tap m50.88 deep 8200 fix ed posts 25 400 527 t hr ead m5 0.8 (c) base (d) w ing bolt 1025 22 95 300 0.2 0.5 750.2 38 claccessed by university of south australia on 06 oct 2007the standard is downloaded from standard sharing330 44 65 19 (e) s wing ing arm toleranc ed dimensions ar e mandat or ydimensions in millimetresfigure 1 proportional caliper arrangement and detailsaccessed by university of south australia on 06 oct 20077 as 1141.142007appendix auncertainty of measurement(informative)a1 generalthe uncertainty of measurement is the range of values within which the test result can be said to lie within a specified level of confidence.as iso/iec 17025, general requirements for the competence of testing and calibration laboratories, requires that testing laboratories have and apply procedures for estimating uncertainty of measurement. clause states that: when estimating uncertainty of measurement, all uncertainty components which are of importance in the given situation shall be taken into account using appropriate methods of analysis. suitable methods of analysis are detailed in iso gum, guide to the expression of uncertainty in measurement.a2 measure of uncertainty of componentswhen required, the uncertainty of measurement should be estimated for each test performed and it is appropriate for testing of aggregates that a coverage factor of 2 for 95% confidence limits be used.when estimating the uncertainty of measurement for this test, the following should be considered as components of uncertainty:(a) mass of each fraction.(b) mass of elongated particles. (c)mass of flat particles.(d) constant mass.(e) the percentages retained in each size fraction (from sieve particles).(f) change in proportions retained due to removal of undersize and oversize particles.(g)reduction ofthe sampleto obtain at least 100 particles (uncertainty of representativeness).(h) caliper ratio.(i) flatness assessment.(j) elongation assessment.(k)rounding at the calculation stage. standards a.auaccessed by university of south australia on 06 oct 2007the standard is downloaded from standard sharingas 1141.142007 8this australian standard was prepared by committee ce-012, aggregates and rock for engineering purposes. it was approved on behalf of the council of standards australia on 4 june 2007 and published on 12 september 2007.the following are represented on committee ce-012: arrb transport researchaustroadsaustralasian railway associationaustralasian slag associationaustralian asphalt pavement associationaustralian chamber of commerce and industrybureau of steel manufacturers of australiacement concrete and aggregates australiaengineering and construction laboratories associationinstitute of quarrying australianational association of testing authorities australiakeeping standards up-to-datestandards are living documents which reflect progress in science, technology and systems. to maintain their currency, all standards are periodically reviewed, and new editions are published. between editions, amendments may be issued. standards may also be withdrawn. it is important that readers assure themselves they are using a current standard, which should include any amendments which may have been published since the standard wa