Additional User Manual · The dynamic CBR- test, in particular the field test, is a material test for intact samples to determine what degree of compaction can be achieved. The dynamic

Additional User Manual

for the

dynamic CBR test

Field test

Benzstraße 1, 39576 Stendal (Germany) Tel: +49(0) 3931 / 25273 0 Fax: +49(0) 3931 / 25273 10

www.zorn-instruments.de [email protected] Subject to change. Stand: 05.07.2011

Measurement device ZFG 3000

10kg Dropping weight

CBR Hardware Field

test

Table of contents

1 Application ..............................................................................................................................5

2 Scope of supply ......................................................................................................................6

3 Alteration to the bearing bolt .................................................................................................7

4 Execution of a dynamic CBR Field test.................................................................................9

4.1 Preparation........................................................................................................................9

4.2 Execution of a measurement .........................................................................................10

4.3 Evaluation of results.......................................................................................................10

4.4 After the measurement...................................................................................................10

5 Care and Maintenance ..........................................................................................................11

6 Technical information...........................................................................................................11

6.1 Plunger ............................................................................................................................11

6.2 Field plate with Plunger guide and guide tube.............................................................11

7 Correlations ...........................................................................................................................12

8 Warranty ................................................................................................................................13

Supplementary User Manual Dynamic CBR-Test

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Notice/Preliminary remark

The manual provides additional information needed to perform a dynamic field CBR test. For

the main instrument (for the 300mm configuration - 10/15kg) refer to the Standard Operating

Manual.

As a settlement measurement device can be used:

ZFG 3000 GPS

Since the delivery configuration may vary according to the customer, this Manual assumes that

the user has a 300mm loading plate and a 10kg dropping weight.

Make sure the bearing spigot on the loading plate is suitable for CBR.

(The bearing spigot and accelerometer housing has a built-in accelerometer sensor with

a 5 mm washer)

If the requirements are not met, the loading plate has to be returned to ZORN INSTRUMENTS

for modification.

Additional User Manual Dynamic CBR-Test

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1 Application The dynamic CBR-test may be used alternatively to the static CBR-test according to the Technical Regulations for soil and rocks in road construction, TP BF - StB Part B 7.1. Due to its little effort of time, it is used as a quick testing method in line with the self-monitoring for the regulation of the production of mineral mixtures. An advantage towards the CBR- test according to TP BF – StB Part B 7.1 is the omission of a loading frame and the corresponding static loading device (pressure test machine). Instead of this, a loading device according to TP BF – StB Part B 8.3 is used.

The dynamic CBR- test, in particular the field test, is a material test for intact samples to determine what degree of compaction can be achieved.

The dynamic CBR – value (CBRd) is a complex cohesiveness characteristic, that depends on the cohesiveness, the grain shape, the frost-resistance and the grain surface, the grain mixture, the content on fine particles, the percentage of water and the compaction of the mineral mixture.

It conduces to e.g. the determination of frost-resistance or the evaluation of trafficability and compaction of used mineral mixtures.

The calculation of the dynamic CBR value occurs according to the following equation:

CBRd=87,3*s0,59

where s is the dynamic settlement amplitude.


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APicture 1: CBR Field test Single Components

2 Scope of supply 1 Plunger (Picture 1 Nr. 1) 1 Plunger guide (Picture 1 Nr. 2) 1 Guide tube (Picture 1 Nr. 3) 4 Half discs (Picture 1 Nr. 4) 1 Field plate (Picture 1 Nr. 5) 1 Hexagon Screwdriver 8mm

1

2

3

4

5

Depending on the equipment, it may be possible that there already is a bearing bolt on the plunger (see picture 3 No. 1). Otherwise, the bearing bolt of the loading plate of the Light Weight Deflectometer must be used. To change the bearing bolt please read Chapter 3 – Alteration to the bearing bolt. For the execution of the test, an entire bearing bolt must be on the plunger.


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3 Alteration to the bearing bolt Should there be no bearing bolt on the plunger, it has to be transposed from the loading plate to the plunger. The bearing bolt contains the acceleration sensor that is needed for the measurement. This chapter explains the alteration.

Required tools: Hexagon screwdriver (8mm)

Please ensure a clean environment. If parts are dirty, please clean them before assembly. For the alteration to the bearing bolt of the loading plate, please follow these steps:

1. Turn the loading plate upside down (bearing bolt down) 2. The 4 screws (M8x25), which hold the bearing bolt, need to be unscrewed. 3. Take the loading plate off the bearing bolt. Take care that the spring rings of the screws

do not get lost. 4. Unscrew the cushioning disc (Picture 3, No.2) from the plunger (M8x16) 5. Screw the cushioning disc onto the bearing bolt. Use the screws M8x25 with spring disc.

Make sure the cushioning disc is screwed on the right way around. The screw heads must be fastened properly so that they do not stick out anymore.

6. Screw the cushioning disc with the bearing bolt onto the plunger. Use the screw M8x25 with spring disc.

The deconstruction occurs in reverse order.


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Picture 3: Plunger Single components

Picture 2: Loading plate Single components

1

2

4

3

1. Bearing bolt 2. Cushioning disc 3. Plunger 4. Loading plate


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Picture 4: Complete assembly of the CBR-field test

4 Execution of a dynamic CBR Field test

4.1 Preparation

1. The testing location must be prepared so that the field plate can be put down horizontally. 2. Put the field plate on the test spot. The play must not rock. 3. Put all four half-discs on the field plate. 4. Put the guide tube and the plunger guide on the field plate and screw them in place using

the knurled nut. 5. Put the plunger in the plunger guide. The CBR-assembly must look like shown in picture

4.

6. Connect the settlement measurement device and the bearing bolt on the plunger using the measurement lead.

7. Carefully put the loading device on the plunger.

Note that for the CBR test pre-loads must not be executed.


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4.2 Execution of a measurement

After preparing the test area and the assembly of the device, the actual measurement can be started with the following steps:

1. Switch on the settlement measurement device and switch to ´´CBR´´ using the MODE button.

2. Start the measurement on the settlement measurement device. 3. Disengage the transport security element and engage the dropping weight into the

release mechanism. (To exclude damage, please ensure the proper locking of the transport security element during transport.)

4. Hold the bar vertically and disengage the dropping weight when the measurement device displays the note to do so.

5. Catch the weight when it comes back up, slowly bring it down to the bottom and engage the transport security mechanism.

4.3 Evaluation of results

The display of results depends on the used settlement measurement device. Instead of the Evd-value, the CBRd –value in % is shown.

4.4 After the measurement

After the execution of a measurement, the device may be switched of. The disassembly of the device occurs in reverse order to the assembly. If applicable, please note Chapter 5 Care and Maintenance.


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5 Care and Maintenance All metal parts must be cleaned of all dirt using a dry cloth. Tough stains may be removed using ethyl alcohol or petroleum. During the transport, all parts must be put away safely.

6 Technical Information

6.1 Plunger

Width (max) 210 mm

Height incl. bearing bolt 385 mm

Weight incl. bearing bolt 15 kg

6.2 Field plate with plunger guide and guide tube

Diameter 300 mm

Height 155mm

Weight (incl. half discs) ca. 440 g


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7 Correlations For information purposes only, no responsibility taken fort he correctness of the information


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8 Warranty From the day of delivery on we furnish a guarantee over 12 months in such a manner, that we will choose to either repair or replace the faulty parts free of charge.

We do not grant warranty for damage due to improper use, normal wear-and-tear, improper handling, incorrect treatment, insufficient care and maintenance, use of non-original parts, higher force or transport.

Benzstraße 1

D – 39576 Stendal

Tel. +49(0)3931 / 25273 – 0

Fax +49(0)3931 / 25273 – 10

www.zorn-instruments.de [email protected]

Documents

Additional User Manual · The dynamic CBR- test, in particular the field test, is a material test for intact samples to determine what degree of compaction can be achieved. The dynamic