QEST Platform 4.91
Applies to QESTLab

There are a number of elements common to every California Bearing Ratio (CBR) test in QESTLab. This article describes the functionality of these elements. For differences between specific standards or test method bodies please refer to the article specific to that test method or standards body.

Worksheet Layout

QESTLab worksheets for this test type are laid out in the following manner. Note that

Individual elements may be named slightly differently for the purposes of familiarity in different regions but the main elements remain largely the same.
The units shown on the test will differ based on the units configuration of the QESTLab system in use and potentially document level options.

There are four tabs that need to be considered, described in the following section below. Starting from the top left tab and moving to the right, these are:

The Equipment tab for recording and displaying the equipment used along with the calibrated measurements for each equipment type that is required for the test method.
The Sample Preparation tab for recording and calculating preparation requirements for the test method, these may include:
- Oversize material
- Plasticity level of the sample (imported or entered manually)
- Compaction results including curing time, dry density and optimum moisture content
- Density Determination for the sample
- Sample moisture content (imported or entered manually)
- Sample preparation
- Moisture content required for density determination
The Soaking & Moisture tab for recording swell readings if the sample is soaked.
The CBR Results tab for recording the raw load data from the loading machine needed for plotting the load-penetration curve.

Equipment

All equipment used for the given test is selected on the Equipment tab of the worksheet.

The following equipment can be selected on the worksheet:

Equipment label	Qest ID	Notes
Balance	30005
Water Bath	30045
Swell Gauge	30037
Proving Ring	30034	The following value will be imported from the selected proving ring's calibration value (if it exists): Seating Deflection Entering or importing the value on this tab will set and lock the value for the test portions.
Load Cell	30078	The following value will be imported from the selected load cell's calibration value (if it exists): Seating Load Entering or importing the value on this tab will set and lock the value for the test portions.
Penetration Piston	30092	The following value will be imported from the selected penetration piston's calibration value (if it exists): Diameter (mm) Entering or importing the value on this tab will set and lock the value for the test portions. The Surface Area value is automatically calculated using the diameter value.
Loading Machine	30090	The following values will be imported from the selected loading machine's calibration values (if these exist): Rate of Penetration Maximum Load will be imported into Loading Capacity on the worksheet Entering or importing the value on this tab will set and lock the value for the test portions.
Hammer	30003	The following value will be imported from the selected hammer's calibration value (if it exists): Weight will be imported into Mass on the worksheet Entering or importing the value on this tab will set and lock the value for the test portions.
Surcharge Weights	30068	Values are populated from the Weight equipment type. The following value will be imported from the selected weight's calibration value (if it exists): Weight will be imported into Surcharge Mass on the worksheet Entering or importing the value on this tab will set and lock the value for the test portions.
Mould	30002	Values are populated from the Density Mould equipment type. The following values will be imported from the selected density mould's calibration values (if these exist): Mould Mass will be imported into Mass on the worksheet Mould Volume will be imported into Volume on the worksheet Height Diameter Entering or importing the value on this tab will set and lock the value for the test portions.
Spacer	30081	The following values will be imported from the selected spacer's calibration values (if these exist): Mass Volume Height Diameter Entering or importing the value on this tab will set and lock the value for the test portions.
Moisture COntent Method
Oven	30004	Available in AU CBR tests only
Sand Bath	30049	Available in AU CBR tests only
Microwave Oven	30020	Available in AU CBR tests only
Hotplate	30010	Available in AU CBR tests only
Infrared Light	30021	Available in AU CBR tests only

Imported Data

The following data is imported onto this test from other tests.

Result

Allowable Test Methods

Found by

Imported To

Used for

MDD Sample

All maximum dry density tests

Sibling tests

MDD & OMC fields on the sample preparation tab

The imported MDD value is used to calculate the mass of wet soil per layer required to reach the specified lab density ratio.

The imported OMC value is used in conjunction with the sample moisture content to determine the mass of water removed/added to the sample to reach specified lab moisture ratio.

Moisture Content

All moisture content tests

Sibling tests

Sample MC field on the sample preparation tab

The imported value is used to determine the mass of water removed/added to the sample to reach specified lab moisture ratio.

Data Entry

Data Entry can be broken down into the four tabs explained below.

Equipment

The Equipment tab will record the equipment items used in the test and also use data from the items that will be used in subsequent calculations. In order to calculate values, the CBR test requires the equipment section to be completed.

The data used on the equipment tab includes details such as:

Proving Ring - Seating Deflection (if the proving ring is selected, users will be allowed to enter the proving ring reading into the Results tab, if this is used it must be properly calibrated within QESTLab.)
Load Cell - Seating Load (if the load cell is selected, users will be allowed to enter load values directly into the Results tab.)
Penetration Piston diameter and surface area
Rate of Penetration of Loading Machine and it's Loading Capacity - error message when load is reached
Mass of Hammer
Mould mass, volume, height and diameter

AU Version

US Version

Spacer - mass, volume, height and diameter

AU Version

US Version

Volume Calculations

Most of the equipment data will not affect the CBR calculations or results with the exception of the Mould and Spacer measurements. If values in these frames are entered incorrectly or in the wrong format then test result calculations will be affected. The calculations used to determine the effective volume of the mould can be a bit vague between each test method and this can lead to a difference in results. While each test method sets out calculations for density, there is some variation between test methods in the calculations for the volume of the specimen. The method for entering data in the Mould and Spacer frames is determined according to the standard used. After entering values for volume, height and diameter of both the Spacer and Mould, the sample volume result field will be calculated. More information on the methods used to calculate the sample volume can be found /wiki/spaces/QPS/pages/1023836363. The correct method of data entry for each frame is covered in the individual page specific for each test method located under the Test Methods section of this page.

To carry out a laboratory test, soil is mixed with the required amount of water, typically Optimum Moisture Content (OMC) for the required compactive effort, which is typically a percentage of the Maximum Dry Density (MDD). The soil is then compacted into a laboratory mould. The mould is assembled with a steel spacer at the bottom so that not all the volume of the mould is occupied by compacted soil.

Sample Preparation

The data entered and imported onto this tab will determine the mass of wet soil needed and mass of wet soil per layer needed for the preparation of the test specimen. This data is used to prepare the specimen in order to reach the Specified Lab DR value and Specified Lab MR value entered on this tab.

The order of data entry on the sample preparation tab is as follows:

Oversize frame
Plasticity frame (this step is not required in US CBR screens)
The following Compaction frame data:
1. Number of blows per layer
2. number of layers
3. Import MDD sample
In Situ/Bulk Moisture Content (US - Sample Moisture Content) frame
Sample Preparation frame
The following Compaction frame data:
1. Curing start
2. Curing finish
Moisture Content for Density Determination frame
Mould + compacted soil on the Density Determination frame

Only one dry mass field is presented for the Mass of Container + Dry field used for the determination of moisture content. Depending on the configuration and test method being used there may be rules built into the worksheet determining when constant dry mass has been reached. If such a rule exists, a Moisture Content value will not be calculated until such time as constant dry mass has been determined to have been reached. If such a rules exist, they are detailed on the page for the particular test method.

Soaking & Moisture

The Soaking & Moisture tab is used if soaking of the test specimen is required.

If a test specimen is soaked then the sample is soaked checkbox should be checked on this tab to determine:

Test Date - to calculate this field enter the soak start date and number of days in the Soaking frame.
Swell value - to calculate this field enter the initial reading and final reading in the Soaking frame.
Moisture content + wet and dry density of the sample after soaking
Moisture Content and Moisture Ratio at different levels after penetration

The frames located in this tab differs from test method to test method. These are further described in the articles related to each given test method.

Only one dry mass field is presented for the Mass of Container + Dry field used for the determination of moisture content. Depending on the configuration and test method being used there may be rules built into the worksheet determining when constant dry mass has been reached. If such a rule exists, a Moisture Content value will not be calculated until such time as constant dry mass has been determined to have been reached. If such a rules exist, they are detailed on the page for the particular test method.

CBR Results

The CBR results tab is used to enter the loading cell data related to the depth of penetration of the penetration piston. Data is entered in the Raw Load column (highlighted below) and is automatically plotted on the load-penetration chart. The Seating Load and Loading Capacity from the Equipment screen will affect the Load results.

Data can also be entered into the Dial Gauge column and a Load calculated if a proving ring with the appropriate calibration values is selected on the equipment tab of the test screen.

The plotted data is what is used to determine the Correction Line and CBR at 2.5mm and 5.0mm. These values can be automatically populated with with the Auto checkbox or they can be manually entered using the From and To fields. The Correction Line is used where the load-penetration curve concaves upwards initially, because of surface irregularities or other causes so the zero point can be adjusted.

Calculated Results

Equipment Tab

For the following fields, in order to calculate:

Surface Area value of Penetration Piston, the following can be used
- Free entry of this value
- Importing of this value from the equipment calibration
- Calculation of this value by entering a value in the Diameter field
Mould Volume value, the following can be used
- Free entry of this value
- Importing of this value from the equipment calibration record of a density mould
- Calculation of this value by entering Height and Diameter values in the mould frame
Spacer Volume value, the following can be used
- Free entry of this value
- Importing of this value from the equipment calibration record of a density mould
- Calculation of this value by entering Height and Diameter values in the spacer frame

Sample Preparation Tab

For the following fields, in order to calculate:

Percentage Retained on 19.0mm Sieve value, enter or otherwise populate the following fields:
- Total Mass of Sample
- Retained on 19.0mm Sieve
Curing Time, enter the following fields:
- Curing Start Date & Time
- Curing Finish Date & Time
Wet Density, enter the following fields
- MDD on compaction frame
- OMC on compaction frame
- Mould + Compacted Soil on density determination frame
Dry Density, enter the following fields
- MDD on compaction frame
- OMC on compaction frame
- Mould + Compacted Soil on density determination frame
- LMR
Density Ratio, enter the following fields
- MDD on compaction frame
- OMC on compaction frame
- Mould + Compacted Soil on density determination frame
Mass of Dry Sample, enter the following fields
- Sample MC on the sample moisture content frame
- Mass of Wet Sample on the sample preparation frame
Sample Mass at Target MC, enter the following fields
- OMC on the compaction frame
- Sample MC on the sample moisture content frame
- Mass of Wet Sample on the sample preparation frame
Water Removed/Added, enter the following fields
- Specified Lab MR on the sample preparation frame
- OMC on the compaction frame
- Sample MC on the sample moisture content frame
- Mass of Wet Sample on the sample preparation frame
Target Dry Density, enter the following fields
- MDD on compaction frame
- OMC on compaction frame
- Mould + Compacted Soil on density determination frame
Target Wet Density, enter the following fields
- MDD on compaction frame
- OMC on compaction frame
- Mould + Compacted Soil on density determination frame
Mass of Wet Soil Needed, enter the following fields
- Specified Lab DR on the sample preparation frame
- MDD on compaction frame
- OMC on compaction frame
- Mould + Compacted Soil on density determination frame
Mass of Wet Soil per Layer, calculated using the Mass of Wet Soil Needed
Moisture Content for Density Determination, enter the following fields from the same frame
- Mass of Container + Wet
- Mass of Container + Dry 1
- Mass of Container + Dry 2 (depending on test method)
- Mass of Container
Lab Moisture Ratio, enter the following fields
- OMC on compaction frame
- MC from the moisture content for density determination frame

Soaking & Moisture Tab

For the following fields, in order to calculate:

Swell value, enter the following fields
- Initial Reading
- Final Reading
Moisture Content after soaking, enter the following fields
- Mass of Mould + Wet
Percentage of OMC after soaking, enter the following fields
- Mass of Mould + Wet
Wet Density after soaking, enter the following fields
- Mass of Mould + Wet
Moisture Content After Penetration (US - Entire), enter the following fields
- Mass of Container + Wet
- Mass of Container + Dry1
- Mass of Container + Dry2
- Mass of Container
Moisture Content After Penetration (US - Top or Top 1"), enter the following fields
- Mass of Container + Wet
- Mass of Container + Dry1
- Mass of Container + Dry2
- Mass of Container
Moisture Content After Penetration (US - Remainder or Entire), enter the following fields
- Mass of Container + Wet
- Mass of Container + Dry1
- Mass of Container + Dry2
- Mass of Container

CBR Results Tab

The Load value for each penetration interval will be plotted on the chart as it is populated. The Raw Load unit is determined by each test screen, for the example below the raw load is entered in kN.

A Plot Correction Line can be plotted on the CBR chart using the checkboxes on this tab. The selections on this tab will be reflected on chart shown on the test report. The Plot Correction Line is drawn as a tangent through the steepest part of the curve so as to intersect the penetration axis. The intercept with the penetration (X) axis shall be the new Offset value.

The Offset value is used the calculate the CBR at 2.5mm and 5.0mm results. The Offset value will change dependent upon the correction line when it is plotted on the chart.

Kiosk Mode

California Bearing Ratio Single Point tests support kiosk mode data entry and balance interfacing for all masses.

Additionally, the following sections of the test methods supports moisture tin association for navigation to the test screen by scanning a moisture tin barcode for capturing the dry masses:

moisture content for density determination on the Sample Preparation tab
moisture content at different levels (after penetration) on the soaking & Moisture tab

Bulk Entry

This test type requires a significant amount of data entry and the requirements are too complex to capture in a simple grid. Bulk entry screens for california bearing ratio test methods, therefore, show the results from the test in a read-only format.

Reporting

Results are reported on a special test report for california bearing ratio test methods that is a child of the actual test itself. This is due to the charting requirements for most test methods. While the reports are similar for each standards association, there are different report objects for different regions and countries, explained below. The results from the worksheets can be reported on the following test reports.

California Bearing Ratio Test Report

This report is used for AS, QMR, RMS, WA and NZS state california bearing ratio test methods. This test report has the capability of charting the correction line for the zero point. The inclusion of the correction line is controlled through a document level option on the CBR test. Reporting of the load-penetration graph is always displayed on the this test report .An example of the California Bearing Ratio Test Report for the AS 12889.6.1.1 test method is shown below.

Properties

QESTID	18986
Name	California Bearing Ratio Test Report
Child Of	California Bearing Ratio Test

Reported Values

The exact reported values and resolution of these will differ per test method and are explained in the documentation for the specific test methods.

Aggregate/Soil Test Report

This report can be used for AS, QMR, RMS, WA and NZS state california bearing ratio test methods. The load-penetration graph is never displayed on this report, this report can be used when reporting the load-penetration graph is optional. An example of the Aggregate/Soil Test Report showing CBR results for the AS 12889.6.1.1 test method is shown below.

Properties

QESTID	18909
Name	Aggregate/Soil Test Report
Child Of	Sample

Reported Values

The exact reported values and resolution of these will differ per test method and are explained in the documentation for the specific test methods.

Test Methods

Differences from or additional functionality to that described above are captured in the following articles.