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 Lighweight Aggregate Manufacturers
Brick Development Association
British Aggregate 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 Ltd.
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 85/13013 DC

Foreword

This Part of BS 812 has been prepared under the direction of the Cement, Gypsum, Aggregate and Quarry Products Standards Policy Committee, and is a revision of clause 6 of BS 812‑3:1975 which is withdrawn. 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 will be issued as a separate Part or Section of this standard.

The methods described in this revision have not been changed technically from that given in BS 812‑3:1975, but the opportunity has been taken to include a procedure for determining the aggregate impact value of aggregates in a soaked condition. This has been done because some aggregates have a significantly reduced resistance to impact when tested in this condition. With such aggregates, tests on soaked samples give a more reliable indication of their performance in practice.

It is intended that other British Standards should call up BS 812 test methods as the basis for 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 relevant test methods.

Some of the tests in other Parts of BS 812 are of limited application and advice on the use of simpler tests is given, for example, when they can be used for a preliminary sorting of aggregates to see whether more extensive testing is justified.

Reference should be made to BS 812‑101:1984 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 methods for the determination of the aggregate impact value (AIV) which gives a relative measure of the resistance of an aggregate to sudden shock or impact.

Two procedures are described, one in which the aggregate is tested in a dry condition, and the other in a soaked condition.

The methods are applicable to aggregates passing at 14.0 mm test sieve and retained on a 10.0 mm test sieve. For smaller size fractions, a recommended method is described in appendix A. Aggregate sizes larger than 14 mm are not appropriate to the aggregate impact value test.

NOTE 1 For the determination of the resistance of an aggregate to a slowly applied compressive load, see BS 812‑110.

NOTE 2 The titles of the publications referred to in this standard are listed in the inside back cover.

2 Definitions

3 Principle

4 Sampling

5 Apparatus

5.1 General

5.2 Additional apparatus for testing aggregate in a soaked condition

6 Preparation of test portions and specimens

6.1 Test portions

6.2 Test specimens in a dry condition

6.3 For test specimens in a soaked condition

7 Procedure

7.1 Test specimens in a dry condition

7.2 Aggregate in a soaked condition

8 Calculations and expression of results

8.1 Aggregate in the dry condition

8.2 Aggregate in the soaked condition

8.3 Results

9 Precision

9.1

9.2

10 Test report

Publications referred to

BS 812-112:1990

Testing aggregates - Method for determination of aggregate impact value (AIV)

Current

Published:

29 Jun 1990