BS 1881-129-2011 Testing concrete Method for determination of density of partially compacted semi-dry fresh concrete《测试混凝土 测定部分压实半干新浇混凝土密度的方法》.pdf

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1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS 1881-129:2011Testing concretePart 129: Method for determinationof density of partially compactedsemi-dry fresh concretePublishing and copyright informationThe BSI copyright no

2、tice displayed in this document indicates when the documentwas last issued. BSI 2011ISBN 978 0 580 74628 4ICS 91.100.30The following BSI references relate to the work on this standard:Committee reference B/517/1Draft for comment 11/30242749 DCPublication historyFirst edition February 1992Second (pre

3、sent) edition August 2011Amendments issued since publicationDate Text affectedBS 1881-129: 2011 BRITISH STANDARDContentsForeword ii1 Scope 12 Normative references 13 Terms and definitions 14 Apparatus 25 Calibration of the container 46 Sampling 47 Preparing the sample for test 48 Procedure 59 Calcul

4、ation and expression of results 510 Test report 611 Precision 7Bibliography 8List of figuresFigure1Typical tamper for partially compacted semi-dry fresh concrete densitytest 3List of tablesTable 1 Dimensions of container 2Table 2 Precision data for density of partially compacted semi-dry freshconcre

5、te 7Summary of pagesThis document comprises a front cover, an inside front cover, pages i to iv,pages 1 to 8, an inside back cover and a back cover.BRITISH STANDARD BS 1881-129: 2011 BSI 2011 iForewordPublishing informationThis part of BS 1881 has been published by BSI and came into effect on 31Augu

6、st 2011. It was prepared by subcommittee B/517/1Concrete production andtesting and Technical Committee B/517, Concrete and related products. A list oforganizations represented on these committees can be obtained on request totheir secretary.SupersessionThis part of BS 1881 supersedes BS1881129:1992

7、which is withdrawn.Relationship with other publicationsBS 1881 contains test methods for concrete currently used in the UnitedKingdom which are not covered by BS EN 12350, BS EN 12390 or BS EN 12504.Reference is made to the relevant part of BS EN 12350, BS EN 12390 andBS EN 12504 where appropriate.

8、These test methods may be used in conjunctionwith BS EN 206-1.BS 1881 is published in the following parts: Part 113, Method for making and curing no-fines cubes; Part 119, Method for determination of compressive strength using portionsof beams broken in flexure (equivalent cube method); Part 122, Me

9、thod for determination of water absorption; Part 124, Methods for analysis of hardened concrete; Part 125, Method for mixing and sampling fresh concrete in the laboratory; Part 128, Method for analysis of fresh concrete; Part 129, Method for the determination of density of partially compactedsemi-dr

10、y fresh concrete; Part 204, Recommendations on the use of electromagnetic covermeters; Part 206, Recommendations for determination of strain in concrete; Part 207, Recommendations for the assessment of concrete strength bynear-to-surface tests; Part 208, Recommendations for the initial surface absor

11、ption of concrete; Part 209, Recommendations for the measurement of dynamic modulus ofelasticity of concrete; DD 216, Method for the determination of chloride content of freshconcrete.Information about this documentThis part of BS 1881 has been revised to reflect the change from British toEuropean s

12、tandard test methods. It describes a method of test for determiningthe density of partially compacted semi-dry fresh concrete. The density ofcompacted fresh concrete can be measured by the method described inBS EN 12350-6 but that method is not applicable to concrete that cannot becompacted by vibra

13、tion alone.Semi-dry concrete has a very low workability, with a slump generally not morethan 10 mm when measured in accordance with BS EN 12350-2.BRITISH STANDARDBS 1881-129: 2011ii BSI 2011The method developed for this type of concrete relies on compacting it bytamping, as used in the method for ma

14、king no-fines concrete test cubesdescribed in BS 1881-113.The type of concrete tested by this method would typically be used inapplications such as kerb backing, pipe haunching and blinding.Tests in accordance with thispPart of BS 1881 are not applicable to lean concretefor road bases and other full

15、y compacted very low workability concretes whichhave their own methods of density measurement included in their specifications,e.g. the Highways Agency Specification for Highway Works 1 in respect ofhydraulically bound material for roadbase and sub-base.Hazard warningsCAUTION When cement is mixed wi

16、th water, alkali is released. Takeprecautions to avoid dry cement entering the eyes, mouth and nose whilstmixing concrete. Prevent skin contact with wet cement or concrete by wearingsuitable protective clothing. If cement or concrete enters the eye, immediatelywash it out thoroughly with clean water

17、 and seek medical treatment withoutdelay. Wash wet concrete off the skin immediately.Use of this documentIt has been assumed in the preparation of this British Standard that theexecution of its provisions will be entrusted to appropriately qualified andexperienced people, for whose use it has been p

18、roduced.Presentational conventionsThe provisions of this standard are presented in roman (i.e. upright) type. Itsrequirements are expressed in sentences in which the principle auxiliary verb is“shall”.Commentary, explanation and general informative material is presented in smalleritalic type, and do

19、es not constitute a normative element.Contractual and legal considerationsThis publication does not purport to include all the necessary provisions of acontract. Users of British Standards are responsible for their correct application.Compliance with a British Standard cannot confer immunity from le

20、galobligations.BRITISH STANDARD BS 1881-129: 2011 BSI 2011 iiiBRITISH STANDARDBS 1881-129: 2011This page deliberately left blankiv BSI 20111 ScopeThis part of this British Standard contains the method by which the density ofsemi-dry, partially compacted concrete can be obtained for the purpose ofdet

21、ermining the quantity of materials necessary to generate a volume of 1 cubicmetre, also known as the “yield”. The method applies to plain concrete madewith aggregate having a nominal maximum aggregate size, Dmaxof 40 mm orless but not to concrete with a slump of more than 10 mm when tested inaccorda

22、nce with BS EN 12350-2.NOTE 1 The method for the determination of density of concrete with a slump ofmore than 10 mm is described in BS EN 12350-6.NOTE 2 This method is not applicable to concrete designed to conform to therequirements of the Specification for Highway Works 1 which describes a specif

23、icmethod for to be applied to hydraulically bound materials intended for use inhighway pavements.2 Normative referencesThe following referenced documents are indispensable for the application ofthis document. For dated references, only the edition cited applies. For undatedreferences, the latest edi

24、tion of the referenced document (including anyamendments) applies.BS 1881-125, Testing concrete Part 125: Methods for mixing and sampling freshconcrete in the laboratoryBS 8500-1, Concrete Complementary British Standard to BS EN 206-1 Part 1:Method of specifying and guidance for the specifierBS EN 9

25、33-2, Tests for geometrical properties of aggregates Part 2:Determination of particle size distribution Test sieves, nominal size ofaperturesBS EN 12350-1, Testing fresh concrete Part 1: SamplingBS EN 12350-2, Testing fresh concrete Part 2: Slump-testBS EN 12350-6, Testing fresh concrete Part 6: Den

26、sity3 Terms and definitionsFor the purposes of this part of BS 1881 the definitions given in BS 8500-1 andBS EN 12350-6 and the following apply.3.1 densitymass of a quantity of partially compacted semi-dry fresh concrete divided by itsvolume, expressed in kg/m33.2 semi-dry concretevery low workabili

27、ty concrete with a low water content and of a consistencywhich, when measured by the slump test, produces a slump value of less than10 mm which is too low to be measured with precision by the test described inBS EN 12350-2BRITISH STANDARD BS 1881-129: 2011 BSI 2011 14 Apparatus4.1 Balance(s) with an

28、 accuracy of 0.01 kg, calibrated on first use and at leastannually thereafter, and recalibrated after relocation or disturbance usingweights of which the accuracy is traceable to the national standard of mass. Acertificate stating the accuracy shall be obtained from the organization carryingout thes

29、e calibrations.4.2 Sampling container(s), made from non-absorbent material not readilyattacked by cement paste, for receiving increments of the concrete.4.3 Container, watertight rigid cylinder of the dimensions specified in Table 1,made of metal or from a material on which in-use performance test d

30、ata areavailable that demonstrates long-term equivalency to metal, not readilyattacked by cement paste, having a smooth internal face, the rim machined to aplane surface, the rim and base at right angles to the axis, and provided withhandles.4.4 Scoop, as described in BS EN 12350-14.5 Tamper, made o

31、f metal and of robust construction comprising a rammer anda guide tube, secured to the base of which is a flat metal bearing plate (SeeFigure 1 for typical construction). The rammer shall have a mass of 2500 g 25 gand the complete tamper of 7700 g 100 g. The rammer shall be able to fall300 mm 3 mm.

32、The bearing plate shall be circular, of diameter 197.0mm 1.5 mm and thickness not less than 12 mm.NOTE A suitable apparatus is the 2.5 kg rammer for the standard compaction testspecified in BS 1377, made of mild steel and having a circular mild steel bearingplate welded centrally to the bottom of th

33、e guide tube. A similar, but not identical,apparatus that can also be used is described in BS 1881-1134.6 Straight edge, made of steel, not less than 300 mm in length and not lessthan 4 mm in thickness.4.7 Remixing container, as described in BS EN 12350-2.4.8 Square mouthed shovel, as described in B

34、S 12350-2.4.9 Thermometer, to measure the temperature of the fresh concrete to anaccuracy of 1 C.4.10 Glass plate.Table 1 Dimensions of containerNominalcapacitym3InsidediametermmInside heightmmMinimumthicknessof metalmmNominalinternal radiusbetween walland basemm0.01 200.01.5 320.01.5 4.0 20.0BRITIS

35、H STANDARDBS 1881-129: 20112 BSI 2011Figure 1 Typical tamper for partially compacted semi-dry fresh concrete density testKey1 4 holes dia. 62 12 holes dia. 63 Bearing plate 197 1.5 dia. 12 min4 Thick rubber gasketNOTE 1 All dimensions are shown in mm.NOTE 2 This design has been found satisfactory, b

36、ut alternative designs may be usedprovided that the essential requirements are fulfilled.BRITISH STANDARD BS 1881-129: 2011 BSI 2011 35 Calibration of the container5.1 Weigh the empty container (4.3) and glass plate (4.10) to an accuracy of0.01 kg and record the indicated mass.5.2 Place the containe

37、r (4.3) on a horizontal surface and fill with water at atemperature of 20 C 5 C.5.3 Fill the container (4.3) to overflowing and slide the glass plate (4.10) over itto exclude any air bubbles.5.4 Weigh the container (4.3), glass plate (4.10) and water to an accuracy of0.01 kg and record the indicated

38、 mass.5.5 Calculate the volume of the container by dividing the total mass of water(kg), required to fill the container, by 998 kg/m3.5.6 Express the volume (V) of the container in cubic metres to an accuracy of0.01 m.6 Sampling6.1 Obtain the sample of fresh concrete by the procedure described inBS

39、EN 12350-1 or BS 1881-125. Keep the sample covered to minimizeevaporation.6.2 Commence the determination of the density as soon as possible, while theconcrete remains in a fresh and malleable state and not more than 90 min aftersampling.NOTE A shorter period, 30 min might be necessary to ensure the

40、determination ofdensity is made with the concrete in a condition similar to that at the intended timeof use.7 Preparing the sample for test7.1 Empty the sample onto the remixing container (4.3). Ensure that no morethan a light covering of paste is left adhering to the sample container(s).7.2 Thoroug

41、hly mix the sample by shovelling it to form a cone on the samplingtray and turning this over with the shovel (4.8) to form a new cone. Repeat thisoperation three times.7.3 Divide the sample into sub-samples as described in BS EN 933-2 using eitherthe quartering technique or a riffle box of a size ca

42、pable of providing therequired size of sub-sample.7.4 A minimum of two sub-samples are required for the operations described inClause 8.BRITISH STANDARDBS 1881-129: 20114 BSI 20118 Procedure8.1 Use the scoop (4.4) to carefully place a layer of concrete about 110 mm deepinto the container from the fi

43、rst test portion. Level the surface of the concretewith gloved fingers, taking care not to compact it.8.2 Carefully place the circular bearing plate of the tamper (4.5) on top of theconcrete with the axis of the tamper vertical. Raise the rammer to the top of itstravel so that it just touches the to

44、p of the sleeve without slack. Allow therammer to drop freely. Complete 15 such blows.8.3 Repeat 8.1 and 8.2 for a second and third layer of concrete.8.4 Create a fourth layer, by overfilling the container and slightly heaping theconcrete towards the centre.8.5 Apply five blows of the rammer as desc

45、ribed in 8.2.8.6 Remove the tamper (4.5) and add or remove sufficient concrete such thatafter a further 10 blows the surcharge of concrete is between 5 mm and 10 mmabove the rim of the container.8.7 If the surcharge is not between 5 mm and 10 mm after completion ofcompaction then repeat 8.1 to 8.6 w

46、ith a fresh specimen.8.8 With the straightedge (4.6), remove the surplus concrete using a sawingaction about 5 mm above the rim. Remove large aggregate particles protrudingabove the rim individually.8.9 Strike the concrete off level with the rim and fill any holes with fines fromthe surplus concrete

47、, to obtain a reasonably flat and level surface, taking carenot to overcompact the concrete by applying undue pressure when finishing thesurface.8.10 Weigh the filled container, subtract the mass of the empty container andrecord the mass of concrete in the container (4.3), to the nearest 0.01 kg.8.1

48、1 Empty and clean the container and then repeat 8.1 to 8.9 on the secondtest portion.9 Calculation and expression of results9.1 Calculation of densityCalculate the density, D, (in kg/m3) for each test portion using the followingequation:D5mv(1)wherem is the mass of concrete sample in the container (

49、in kg);V is the capacity of the container (in m3).Express the result to the nearest 10 kg/m3.Calculate the mean of the two determinations and the difference betweenthem. If the difference is 40 kg/m3or more discard the results and repeat thetest on a new sample of concrete.If the difference is less than 40 kg/m3, report the mean.BRITISH STANDARD BS 1881-129: 2011 BSI 2011 59.2 Calculation of the volume of concrete per batchIf the volume of concrete produced per batch, Vb, is required, calculate it (in m3)us