Unknown BRITISH STANDARD BS EN 12697 9 2002 Bituminous mixtures — Test methods for hot mix asphalt — Part 9 Determination of the reference density The European Standard EN 12697 9 2002 has the status[.]
BRITISH STANDARD Bituminous mixtures — Test methods for hot mix asphalt — Part 9: Determination of the reference density The European Standard EN 12697-9:2002 has the status of a British Standard ICS 93.080.20 12&2331,5 mm Normative references This European Standard incorporates by dated or undated reference, provisions from other publications These normative references are cited at the appropriate places in the text, and the publications are listed hereafter For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision For undated references the latest edition of the publication referred to applies (including amendments) prEN 12697-6, Bituminous mixtures — Test methods for hot mix asphalt — Part 6: Determination of bulk density of bituminous specimen by hydro-static method prEN 12697-30, Bituminous mixtures — Test methods for hot mix asphalt — Part 30: Specimen preparation, impact compactor prEN 12697-31, Bituminous mixtures — Test methods for hot mix asphalt — Part 31: Specimen preparation, gyratory compactor prEN 12697-32, Bituminous mixtures — Test methods for hot mix asphalt — Part 32: Laboratory compaction of bituminous mixtures by a vibratory compactor prEN 12697-33, Bituminous mixtures — Test methods for hot mix asphalt — Part 33: Specimen preparation, slab compactor prEN 12697-35, Bituminous mixtures — Test methods for hot mix asphalt — Part 35: Laboratory mixing Terms and definitions For the purposes of this European Standard, the following terms and definitions apply 3.1 conventional reference density value expressed as mass per unit volume that is used as a reference for the density of specimens for the determination of compaction degree, results of type testing, etc NOTE For a given bituminous mixture, the conventional reference density determined by the procedure using the gyratory compactor, generally varies according to the nominal thickness of the layer in which it is intended to be used 3.2 conventional refusal density value expressed as mass per unit volume of the specimen compacted to a very high compaction energy or refusal in accordance with prEN 12697-31 and prEN 12697-32 with the gyratory and vibratory compactor respectively and determined in accordance with prEN 12697-6 NOTE The conventional refusal density is independent of the thickness of the layer EN 12697-9:2002 (E) 3.3 compaction degree ratio of the bulk density of the specimen determined in accordance with prEN 12697-6 (dried bulk density if applicable to a core) to the conventional reference density for the corresponding thickness of layer expressed as a percentage 3.4 percentage refusal density (PRD) ratio of the initial dried bulk density of the specimen determined in accordance with prEN 12697-6 to the conventional refusal density expressed as a percentage Principle 4.1 The conventional reference density is determined in one of the following two ways: a) by compacting by impact compactor specimens obtained from laboratory or plant mixtures with a predetermined number of hammer blows on each side of the specimens; NOTE b) The number of blows is dependent upon the product type and traffic category by compacting by gyratory compactor specimens obtained from laboratory or plant mixtures at a prescribed number of gyrations which varies according to the nominal thickness of the layer in which it will be used NOTE The number of gyrations is stated in the product standard 4.2 The conventional refusal density is determined in one of the following two ways: a) by compacting by gyratory compactor specimens obtained from laboratory or plant mixtures for 200 gyrations; b) by compacting by vibratory compactor a heated core sample to refusal NOTE Until such time as relevant data is obtained from the use of the procedure with a vibrating hammer for other product types, this European Standard only applies to asphalt concrete base and binder course mixtures The initial dried bulk density of a core specimen of a dense bituminous mixture is measured The compaction degree is calculated as the ratio between that density and the conventional reference density or the percentage refusal density is calculated as the ratio between that density and the conventional refusal density NOTE density The conventional reference or refusal density can be measured on the core specimen after its initial dried bulk The uses of compaction methods are summarized in Table Table Compaction Method Parameter Impact compactor Gyratory compactor Vibratory compactor Conventional reference density Yes Yes Not normally Conventional refusal density No Yes (at 200 gyrations) Yes Compaction degree Yes Yes Not normally No Yes (at 200 gyrations) Yes Percentage (PRD) refusal density EN 12697-9:2002 (E) Materials and Apparatus The materials and apparatus for determining the reference density shall conform to prEN 12697-30, prEN 12697-31, and prEN 12697-32 for impact, gyratory and vibratory compaction respectively Procedure 6.1 General If required for calculation of the compaction degree or the percentage refusal density, the initial dried bulk density of core samples shall be measured in accordance with prEN 12697-6 6.1.1 Impact compaction The apparatus and procedure for the preparation of the specimens shall be in accordance with prEN 12697-30 6.1.2 Gyratory compaction The asphalt mixture shall be prepared and introduced into the mould The gyratory compactor shall be adjusted and operated, and the curve of density versus number of gyrations shall be established in accordance with prEN 12697-31 The reference density shall be the average of the results for three specimens If the sample of bituminous mixture is cut or cored in a compacted layer, it shall be reheated in a preheated oven at the temperature specified in prEN 12697-35 and retained in the oven until the centre of the core has attained the specified temperature, broken down, and the mass (M) specified in prEN 12697-32 is introduced into the mould, which is brought to the test temperature specified in prEN 12697-35 The conventional reference density or refusal density of a core shall be the result obtained on one core only 6.1.3 Vibratory compaction For the determination of refusal density, the specimens for test shall be prepared in accordance with prEN 12697-33 6.2 Determination of density of specimens The initial dried bulk density of core samples shall be determined in accordance with prEN 12697-6 The bulk density of reference specimens shall be determined in accordance with prEN 12697-6 Calculation and expression of results The initial dried bulk density and reference densities shall be calculated in accordance with prEN 12697-6 The compaction degree (Crg or Cri) shall be calculated from the following equations: Crg = ρ bc ⋅ 100 ρ rg (1) where Crg is the compaction degree (gyrator compactor), in percent (%); ρ bc is the initial dried bulk density, in kilograms per cubic metre (kg/m ); ρ rg is the conventional reference density (gyrator compactor), in kilograms per cubic metre (kg/m ) 3 EN 12697-9:2002 (E) C ri = ρ bc ⋅ 100 ρ ri (2) where Cri is the compaction degree (impact compactor), in percent (%); ρ bc is the initial dried bulk density, in kilograms per cubic metre (kg/m ); ρ ri is the conventional reference density (impact compactor), in kilograms per cubic metre (kg/m ) 3 The compaction degree shall be expressed to the nearest 0,1 % The PRD (Cref,g or Cref,v) shall be calculated from the following equations: Cref, g = ρ ρ bc ref, g ⋅ 100 (3) where Cref,g is the refusal density (gyrator compactor), in percent (%); ρ bc is the initial dried bulk density, in kilograms per cubic metre (kg/m ); ρ ref,g is the conventional refusal density (gyrator compactor), in kilograms per cubic metre (kg/m3) or Cref, v = ρ ρ bc ref, v ⋅ 100 (4) where Cref,v is the refusal density (vibrator compactor), in percent (%); ρ bc is the initial dried bulk density, in kilograms per cubic metre (kg/m ); ρ ref,v is the conventional refusal density (vibrator compactor), in kilograms per cubic metre (kg/m3) The PRD shall be expressed to the nearest 0,1 If the core has been split into layers or cut in half, the PRD of the core shall be the average of the value obtained for each layer Test report The test report shall state that the reference density was determined in accordance with this European Standard and shall include the following additional information: a) name and address of the testing laboratory; b) a unique serial number for the test report; c) name of the client; d) description and an identification of the sample, and the date of receipt; EN 12697-9:2002 (E) e) identification of the test method including method of specimen preparation of reference samples, test conditions, and information on the use of talcum powder or an inert filler, where appropriate for vibratory compaction; f) measured diameter when cores are used; g) total depth of core received; h) depth of individual test specimens and whether loose material was removed; i) individual values of reference density, refusal density, compaction degree and PRD, when applicable; j) signature of the person accepting technical responsibility for the test report; k) date of issue Precision 9.1 Impact compaction The precision data for the bulk density given in prEN 12697-6 are also valid for the reference density 9.2 Compaction degree Repeatability: Standard deviation: σ r = (0,36 + 0,006 A) %; Reproducibility: Standard deviation: σ R = (0,48 + 0,015 A) %; where A is the percentage of mass of mineral aggregate larger than 11,2 mm in the total mixture R = 2,77 σ R Limit of reproduction: Range of confidence: if one test result x: x ± qR1 = x ± 1,96 σ R if one test result as a mean value X from two results: X ± qR2 = X ± 1,39 σR if one test result as a mean value X from three results: X ± qR3 = X ± 1,13 σ R 9.3 Gyratory compaction A study on repeatability and reproducibility of the conventional reference density has been carried out with 19 laboratories working with the same type of test device under the following conditions (see Table 2): hmin = 150 mm; diameter of moulds = 160 mm; different bituminous mixtures; number of repetitions per type of mixture = 10 EN 12697-9:2002 (E) Table — Repeatability, reproducibility Material/Regime 9.4 Repeatability kg/m Reproducibility kg/m Gap graded asphalt concrete for thin wearing course at 40 gyrations 21 33 Asphalt concrete for wearing course at 80 gyrations 16 24 Asphalt road base at 120 gyrations 19 23 Vibratory compaction The best current estimates for repeatability and reproducibility of the determination of PRD are as follows: Repeatability 1,2 Reproducibility 1,8 NOTE The precision data were determined from an experiment concluded in 1982 using 10 laboratories and 60 samples The repeatability and reproducibility values given above apply for a range of PRD values from 92,3 to 99,2 11 BS EN 12697-9:2002 BSI — British Standards Institution BSI is the independent national body responsible for preparing British Standards It presents the UK view on standards in Europe and at the international level It is incorporated by Royal Charter Revisions British Standards are updated by amendment or revision Users of British Standards should make sure that they possess the latest amendments or editions It is the constant aim of BSI to improve the quality of our products and services We would be grateful if anyone finding an inaccuracy or ambiguity while using this British Standard would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover Tel: +44 (0)20 8996 9000 Fax: +44 (0)20 8996 7400 BSI offers members an individual updating service called PLUS which ensures that subscribers automatically receive the latest editions of standards Buying standards Orders for all BSI, international and foreign standards publications should be addressed to Customer Services Tel: +44 (0)20 8996 9001 Fax: +44 (0)20 8996 7001 Email: orders@bsi-global.com Standards are also available from the BSI website at http://www.bsi-global.com In response to orders for international standards, it is BSI policy to supply the BSI implementation of those that have been published as British Standards, unless otherwise requested Information on standards BSI provides a wide range of information on national, European and international standards through its Library and its Technical Help to Exporters Service Various BSI electronic information services are also available which give details on all its products and services Contact the Information Centre Tel: +44 (0)20 8996 7111 Fax: +44 (0)20 8996 7048 Email: info@bsi-global.com Subscribing members of BSI are kept up to date with standards developments and receive substantial discounts on the purchase price of standards For details of these and other benefits contact Membership Administration Tel: +44 (0)20 8996 7002 Fax: +44 (0)20 8996 7001 Email: membership@bsi-global.com Information regarding online access to British Standards via British Standards Online can be found at http://www.bsi-global.com/bsonline Further information about BSI is available on the BSI website at http://www.bsi-global.com Copyright Copyright subsists in all BSI publications BSI also holds the copyright, in the UK, of the publications of the international standardization bodies Except as permitted under the Copyright, Designs and Patents Act 1988 no extract may be reproduced, stored in a retrieval system or transmitted in any form or by any means – electronic, photocopying, recording or otherwise – without prior written permission from BSI BSI 389 Chiswick High Road London W4 4AL This does not preclude the free use, in the course of implementing the standard, of necessary details such as symbols, and size, type or grade designations If these details are to be used for any other purpose than implementation then the prior written permission of BSI must be obtained Details and advice can be obtained from the Copyright & Licensing Manager Tel: +44 (0)20 8996 7070 Fax: +44 (0)20 8996 7553 Email: copyright@bsi-global.com