Committees responsible for this British Standard

The preparation of this British Standard was entrusted by the Cement, Gypsum, Aggregates and Quarry Products Standards Policy Committee (CAB/-) to Technical Committee CAB/2, upon which the following bodies were represented:

Aggregate Concrete Block Association
Association of Consulting Engineers
Association of Consulting Scientists
Association of Lightweight Aggregate Manufacturers
Brick Development Association
British Aggregrate Construction Materials Industries
British Cement Association
British Ceramic Research Ltd.
British Civil Engineering Test Equipment Manufacturers’ Association
British Geological Sciences
British Precast Concrete Federation Ltd.
British Ready Mixed Concrete Association
British Steel Industry
Building Employers Confederation
Calcium Silicate Brick Association Limited
Chartered Institute of Building
Concrete Society
County Surveyors’ Society
Department of the Environment (Building Research Establishment)
Department of the Environment (Property Services Agency)
Department of Transport
Department of Transport (Transport and Road Research Laboratory)
Electricity Supply Industry in England and Wales
Federation of Civil Engineering Contractors
Institute of Concrete Technology
Institution of Civil Engineers
Institution of Highways and Transportation
Institution of Structural Engineers
Institution of Water and Environmental Management
Mortar Producers Association Limited
Sand and Gravel Association Limited
Society of Chemical Industry

This British Standard, having been prepared under the direction of the Cement, Gypsum, Aggregates and Quarry Products Standards Policy Committee, was published under the authority of the Board of BSI and comes into effect on 29 June 1990

The following BSI references relate to the work on this standard:

Committee reference CAB/2
Draft for comment 84/14033 DC

Foreword

This Part of BS 812 has been prepared under the direction of the Cement, Gypsum, Aggregates and Quarry Products Standards Policy Committee, and is a revision of clause 7 of BS 812‑2:1975, which is withdrawn by amendment. It forms part of a general revision of the 1975 edition of BS 812. As each of the tests, or collection of related tests, is revised it is intended to issue it as a separate Part or Section of this standard.

In the case of the definitive, oven-drying method for the determination of the moisture content, only editorial changes have been made to the procedure described in the previous edition of clause 7 of BS 812‑2:1975. However, in the case of the subsidiary methods, although the modified drying method has been retained under the title of the high temperature method, the siphon-can and buoyancy methods have been omitted as they are rarely used. In their place methods based respectively on the use of a microwave oven and on the reaction of water in the aggregate with calcium carbide have been introduced. These tests are of more limited application than the oven-drying method but are easier to carry out and provide rapid results. In the case of the calcium carbide method, the test procedure has been added as an appendix because of limited availability of information on the apparatus.

It is intended that other British Standards should call up BS 812 test methods as the basis of compliance. Nevertheless, it is not intended that all aggregates should be subjected to all the listed tests. Specifications in other standards should call up only the relevant test methods.

Reference should be made to BS 812‑101 for general guidance on testing aggregates, precision of test methods and variance arising from sampling errors.

A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application.

Compliance with a British Standard does not of itself confer immunity from legal obligations.

1 Scope

This Part of BS 812 describes the following three methods for the determination of the moisture content of aggregates:

oven-drying method (definitive method);
high temperature method;
microwave-oven method for fine aggregate only.

It also describes the calcium carbide method in appendix A.

NOTE The titles of the publications referred to in this standard are listed on the inside back cover.

2 Definitions

3 Principles

3.1

3.2

3.3

4 Sampling

5 Preparation of test portions

6 Definitive, oven-drying method

6.1 Apparatus

6.2 Procedure

6.3 Calculation and expression of results

7 Modified drying methods

7.1 General

7.2 High temperature method

7.3 Microwave oven method; normally limited to fine aggregates

8 Precision

8.1

8.2

9 Test report

Publications referred to

BS 812-109:1990

Testing aggregates - Methods for determination of moisture content

Published:

29 Jun 1990

Withdrawn:

21 Apr 2022