ite sampling&testingof concreteA practical guide for site personnel

FORE\NORD

During the next few years, specifications will change

from using the as 1881 test methods to those given in

the series as 12350: Testing fresh concrete and the

series as 12390: Testing hardened concrete.

Fortunately the tests included on this poster are the

same and the only difference is in the reporting of the

slump and flow values. However on the test certificate,

it is necessary to report the standard used.

An accompanying publication entitled 'Site sampling

and testing of concrete: a site managers guide' has

also been produced to assist site engineers and

managers to ensure that sampling and testing are

carried out correctly. The guide highlights some of the

potential problems associated with using incorrect

procedures.

Don't forget - The test results willbe misleading if

these procedures are not carried out.

Get it right - Otherwise it's a waste of time and could

cost your company money.

For fulldetailsof equipment,testsandrecordssee:as1881: Testing concrete,

aSEN12350:Tesdngfreshconcret~and

as EN 12390: Testing hardened concrete.

Safety

When Portland cement is mixed with water, or even becomes damp, alkalis are released which can be harmful to

the skin. The effect depends on the length of contact, any abrasion, the individual, and the part of the body

involved. Suitable protective clothing should be worn. If eyes are affected they should be washed out without

delay and medical attention sought.

All advice or information in this publication is intended for those who will evaluate the significance and limitations

of its contents anCltake responsibility for its use and application. No liability (including that for negligence) for any

loss resulting from such advice or information is accepted. Readers should note that all publications are subject to

revision from time to time and should therefore ensure that they are in possession of the latest version.

SAMPLING BS1881:Part101orBSEN 12350-1

The standard method

To ensure it is representative of the whole load astandard sample consists of scoopfuls taken fromfour different parts of the load and collected inbuckets.

let very first concrete go

Take a scoopful from part 1

Take a scoopful from part 2

Take a scoopful from part 3

Take a scoopful from part 4

let the last concrete go

Sample as the load is discharged.Scoopfuls must be taken through the moving stream,sampling the whole width and depth - not just thetop part.

Complete a Sampling certificate and record which sampling method was used.

Safety

When Portland cement is mixed with water, or even becomes damp, alkalis are released which can be harmful to

the skin. The effect depends on the length of contact, any abrasion, the individual, and the part of the body

involved. Suitable protective clothing should be worn. If eyes are affected they should be washed out withoutdelay and medical attention sought.

All advice or information in this publication is intended for those who will evaluate the significance and limitations

of its contents an'd take responsibility for its use and application. No liability (including thatfor negligence) for any

loss resulting from such advice or information is accepted. Readers should note that all publications are subject to

revision from time to time and should therefore ensure that they are in possession of the latest version.

BS1881:Part102orBSEN206-1: 2000, clause5.4. 1ThealternativemethodFor an early check on the workability of concreted€livered in a truckmixer this alternative method of

sampling for the slump test may be used. Additionaltolerances will be applicable for concrete sampled bythis alternative method.

'''''-

Sample as the load is discharged.Scoopfuls must be taken through the moving stream,sampling the whole width and depth - not just thetop part.

Let very first concrete go

Take six scoopfuls from the

next 0.3 m3

Take six scoopfuls after the first 0.3m3 has

been discharged.

Do not use this sample to make cubes.BS 1881: Part 101 requires two slump tests when concrete is sampled by the alternative method.

THE SLUMP TEST

Empty the samplingbuckets onto the mixing

tray. Scrape each bucket clean

. Thoroughly remix thesample shovelling intoa heap

. Turn the heap over toform another

. Do this three times

BS 1881: Part 102 orBS EN 12350-2

Flatten the final heap by repeatedlydigging-in the shovel verticallyLiftthe shovel clear each timeIfthe alternative method ofsampling has been used,divide this heap into twoand test each part

Ensure the slump cone is clean anddampPlace the metal plate on a solid levelbase away from vibration or otherdisturbancePlace the cone on the plate andstand on the foot-pieces

Fill the coneinthree equal depthlayersUse the standard slump rodRod each layer 2S timesSpread the blows evenly over thearea

Make sure the rod just penetratesthe layer below

. Heap the concrete above the top ofthe cone before rodding the thirdlayer

.Topup if necessaryUsethe rodwith a sawingandrolling motion to strikethe concretelevelwith the top ofthe cone

Carefullycleanoff spillagefrom sideandbaseplate

. Carefully lift the conestraight up and clear,to a count of between 5and 10 seconds

Complete steps 5 to 8within 150 seconds

Laythe rod across the upturnedslump coneMeasure the distance between the

underside of the rod and the highestpoint of the concrete - the trueslumpRecordthis distance to the nearestSmm if using BS1881: Part 102 or10 mm if using BSEN 123S0-2In all cases record the kind of slumpCheckthe type of slumpIfthe slump isn't true, take a newsample and repeat the test. Ifthe second slump isn't true, getadvice

. Complete the Sampling and testingcertificates

There are three kinds of slump

SlumpiT

1.True

2.Collapse 3.Shear

Youwillneed thisequipmentfor theSlumpTest

Small scoop cf Sampling scoop cP Steel rule /Square-mouthed \ Slump rod / Slump cone and

i}shovel rigidmetalplate

53 <> I!lBuckets or Mixing tray Sampling and' '

wheelbarrow testing certificates "

Cloth

THE FLO\N TEST

First, find a suitable location for the flow table. It

must be placed on a firm flat surface. It may benecessary to prepare an area for the table.

. Empty the sampling bucketsonto the mixing tray

. Scrape each bucket clean

. Thoroughly remix the sampleas described for the slump test

BS1881:Part 105orBSEN 12350-5

Sampling using the standard method isrecommended

Ensure the mould and table are cleanand dampPlace the mould on the centreof the table and stand on thefoot-piecesFillthe mould in two layers,tamping each layer ten times withthe tamping barIfnecessary, add more concrete tofill the top layerUse the tamping bar to strike theconcrete level with the top of themould

\' Carefullyclean off spillage fromaround the mould and table top

Carefully stand on the toeboard at the front of thetable

Wait 30 seconds from striking offCarefully lift the mould straight upand clear, to a count of between 3and 6 seconds

Slowly lift the table top by thehandle until it reaches the upperstop

. Allow the table to fall freely

Repeat this cycle to give a total of15 dropsEach cycle should take about 4seconds

. Measure the largest dimension ofconcrete spread in two directions,

parallel to the table edges. Record the two diameters to

nearest 5mm if using BS 1881: Part105 or 10mm if using BS EN12350-5

If there is a ring of cement pasteseveral mm beyond the coarseaggregate, report that segregationhas occurred

Complete the Sampling and testingcertificates

You will need this equipment for the Flow Test\1 .....'r.""__.I :.r.'8W:IU..-:i ......... (:.8::.l.L!1I818.1::.1.. i. ::.1_....,.

Smallscoop d Sampling scoop cJj Sampling and !!l0:::......, ,testingcertificates '':"-

Square-mouthed \ / Mixing tray

0shovel 700mmrule

Bucketsor

53 13Flowtable

wheelbarrow Mould

Mixingtray

Cloth rQ9 Hardwood

tamping bar

MAKING CUBES BS 1881: Part 108 orBS EN 12390-2

Sample the concrete in the standard manner. Concrete sampled using the alternative method cannotbe used for making cubes.

Check that themoulds are clean and

lightly oiled with allbolts tightened sothat there will be no

leakage. Ensurethat thecorrect halves of themould are used and

that the corner lining

pins are correctlylocated

. Thoroughly remix the

sample as describedfor the slump test

. Fill the mould with

concrete in 50mm layers. Using the special tampingbar. compactthe concrete with not lessthan:

25 tamps for each ofthe two layers in a100mm mould35 tamps for each ofthe three layers in a150mm mould

. Removesurplus concreteand smooth over with afloat

. Wipe the mould edgesclean. Number the moulds foridentification and recorddetails

Cover each mould with adamp cloth and plasticsheetStore inside at normalroom temperature (15'Cto 2S'C) e.g. on top of thecuring tankProtect the cube moulds atall times from high andlow temperatures(especially frost) anddrying windsComplete the Samplingand cube makingcertificates

Youwill need this equipment for Making Cubes

Smallscoop

Square-mouthed

shovel

Tamping bar

Sampling scoop

Damp cloth and

plastic sheet

Buckets or

wheelbarrow

Spanner

8Hide hammer

Cloth

Lightly re-oil the cube moulds with release oil

Cube moulds Mixing tray Sampling, cube

making and storage

certificates

Maximuml Steel float Curing tank

minimum

thermometer ; . -',

Felt tip pen or IBrushand

crayon mouldoil

STORING CUBES BS 1881: Part 111 orBS EN 12390-2

The cubes should be taken from the moulds the day after making, numbered and put in a curing tank.

Record themaximum/minimum

overnight storagetemperatures on thecertificate

. Slacken all nuts

iMAX

MIN lMJ

. Part the sides of themould, tapping gently withthe hide hammerlift off carefully

. Remember, new cubesare easily damagedunless handled carefully

. Mark each cube with itsidentification number ontwo of its cast sides

I' . Place the cubes in the

curing tank. Clean and reassemble themoulds

. Check that the water

temperature iscontrolled at 20.C :t 2.Cand the cubes are covered

by water. Make sure the power

supply is not switched offday or night. Check the temperaturerange daily using themaximum/minimumthermometer

. Keep a record of thereadings

For despatch to testlaboratory, wrap the wetcubes in damp cloths. andthen plastic bags and packin trays

. Attach the sampling.testing. cube making andstorage certificates, plusthe order for testing. tothe package

20.C

......

Ql1ARRYPRODUCTS-ASSOCJ AT ION-

o Quarry Products Association

Firstpublished by the British Cement Association

for the Ready-mixed Concrete BureauPublication number 97. 334

First published 1993

Revised2002. 2004

fS8N07210 14704

Produced by Rudkin Design

Telephone: (01327) 301770

Forfurther information contact:

National Helpline

07004 500 500

(~ )

The Concrete Centre™

The Concrete Centre

Riverside House, 4 Meadows Business Park

Station Approach, Blackwater

Camberley, Surrey GU17 9AB

I.