Applies to QEST Web App

Contents

Overview

The particle density by gas jar test method worksheet can be used to determine the particle density of soils and aggregates. It is based on the methodology of the Determination of Particle Density, Gas Jar method (BS 1377-2 Clause 9.2).

This article provides information on how the various choices available within the QEST App version of this test method provide the required pathways to deal with the variations within the test.

Open

Data Entry

Sample Preparation

Sample Properties

Selection	Action

Selection	Action
Open	Default Used to record material's grain size information. Also affects the following test parameters: Expected specimen size = 200 g ± 20 g Minimum drying time required = 16 h
Open	Used to record material's grain size information. Also affects the following test parameters: Expected specimen size = 200 g ± 20 g Minimum drying time required = 16 h
Open	Used to record material's grain size information. Also affects the following test parameters: Expected specimen size = 400 g ± 40 g Minimum drying time required = 4 h

Sample Mass

The test method requires that the sample mass be “ … approximately 1 kg … “.

This has been interpreted as a range of 1000 g to 1100 g on the worksheet. Values outside this range will cause a warning to be displayed but this does not prevent the test from proceeding.

Preparation Process

Selection	Action

Selection	Action
Open	Default Oversize Material subsection is available for data entry.
Open	Oversize Material subsection is not available for data entry. The % retained on sieve values are set to zero and locked.

Oversize Material (> 37.5mm)

Selection	Action

Selection	Action
Open	Default Sieving method and results are described as “Cumulative”. Retained % on the 37.5 mm sieve is calculated as “Cumulative” . Because each fraction is kept separate and treated differently, the mass retained on each sieve is the individual mass retained, regardless of whether the results are displayed as “Individual” or “Cumulative”.
Open	Sieving method and results are described as “Individual”. Retained % on the 37.5 mm sieve is calculated as “Individual”. Because each fraction is kept separate and treated differently, the mass retained on each sieve is the individual mass retained, regardless of whether the results are displayed as “Individual” or “Cumulative”.

Specimen Drying

Selection	Action

Selection	Action
Open	Default No action required.
Open	Acceptable drying temperature is limited to a maximum of 50 °C. The presence of gypsum, in the sample, is reported.

A minimum of two specimens are required for the test and the worksheet originally displays two columns in the drying grid. More columns can be added to the grid if more than two specimens are required to be dried.

The pre-drying mass (wet mass) of each specimen is checked at the beginning of the drying process and a warning is displayed if this mass is not within the expected limits. (See Sample Properties, above)

This warning does not prevent the test from proceeding, but the test will be non-compliant with the test method if it does and the specimen should be replaced with one that does meet the mass requirements.

Measurements

Particle Density Determination

Exclude Test

Under normal conditions, this checkbox is visible but not available for use.

Open

However, if the individual particle density tests are not within 0.03 Mg/m³, an error is displayed and the checkbox is available for use.

Open

If the checkbox is ticked, the grid columns for both specimens are locked, their results are removed from calculations, and two new columns are added to the worksheet.

To continue with the test, the test needs to be restarted with two new specimens of the same sample.

If after the checkbox is ticked, the cause of the error is found to be a data entry error in the original information, unticking the checkbox will delete the two new columns and allow the original data to be corrected.

Equipment

The following equipment can be selected on the worksheet:

Results

The following test result will always be reported:

• Particle Density

Additionally, the following three results are available for optional reporting (as a group):

• Sieving Method

• Retained 50.0 mm Sieve

• Retained 37.5 mm Sieve

Reporting

The Report checkbox at the end of the Results section allows the selection of optional reportable results.

Open

The results from this worksheet can be reported on the following test report.

Particle Density Test Report (120057)

This report is a child document of the test worksheet. It is automatically added to the sample when the test worksheet is selected.

Mandatory Reporting

Open

Mandatory + Conditional Reporting

Open

Mandatory + Optional Reporting

Open

Properties

Reported Values - Mandatory

These values are always reported.

Reported Values - Conditional

These are only reported if certain conditions in the test method related to drying the specimen are met, such as the drying temperature is 80 °C or less, or, gypsum has been indicated to be present in the sample.

Reported Values - Optional

These values are only reported if the Report checkbox is ticked. They are always reported as group and not individually.

Batch Update Support

This worksheet is not supported on the batch update page.

Work Progress and Complete Status