Committees responsible for this British Standard

The preparation of this British Standard was entrusted by the Technical Sector Board for Building and Civil Engineering (B/-) to Technical Committee CAB/4, upon which the following bodies were represented:

Association of Lightweight Aggregate Manufacturers
Association of Metropolitan Authorities
Association of Quality Pulverised Fuel Ash Suppliers
British Aggregate Construction Materials Industries
British Cement Association
British Civil Engineering Test Equipment Manufacturers Association
British Precast Concrete Federation
British Ready Mixed Concrete Association
Building Employers Confederation
Cement Admixtures Association
Cementitious Slag Makers Association
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 Industry in United Kingdom
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
National House-Building Council
Sand and Gravel Association
Society of Chemical Industry

The following bodies were also represented in the drafting of the standard, through subcommittees and panels:

British Nuclear Fuels plc
United Kingdom Atomic Energy Authority

This British Standard, having been prepared under the direction of the Technical Sector Board for Building and Civil Engineering, was published under the authority of the Standards Board and comes into effect on 31 January 1992

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

Committee reference CAB/4
Draft for comment 89/16059 DC

Foreword

This Part of BS 1881 has been prepared under the direction of the Technical Sector Board for Building and Civil Engineering. All aspects of testing concrete are being included as Parts of BS 1881 from sampling fresh concrete to assessing concrete in structures. Part 201 gives general guidance on the choice of non-destructive test methods, including a bibliography, and should be consulted for advice on methods which complement the use of near-to-surface strength tests or are useful as alternatives.

In recent years, several tests and devices have been developed which give a measure of the insitu strength of concrete near to the surface. Carrying out near-to-surface tests requires only one face of the concrete to be available and this face need not be as smooth as that required for some alternative tests. Although most of these tests measure a property of concrete related to its strength, correlation with compressive strength has to be established experimentally. The results obtained may be used to estimate the strength of the body of the concrete. However, placing, compacting and curing may make the concrete in the surface zone unrepresentative of the concrete at deeper levels. For some methods the same correlation can be used over a wide range of concrete types but this is not universally true. Care should be taken to ensure that the correlations adopted are relevant to the circumstances of use.

Guidance on planning and interpreting tests to assess the strength of concrete in structures is given in BS 6089, which refers to the use of near-to-surface methods. The tests described in this Part of BS 1881 are those for which there is most experience at present. Other near-to-surface techniques may be proposed, usually to meet some particular need, and their use is not precluded by this Part. The recommendations of Clauses 3, 4, 5 and 11 to 13 may usefully be applied to such methods.

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.

Summary of pages

This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 12, an inside back cover and a back cover.

This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.

1 Scope

This Part of BS 1881 gives recommendations on tests that are designed to assess the strength of concrete by causing localized failure in a small zone, typically up to 75 mm from the surface, according to the method. The recommendations cover the following test methods:

internal fracture;
pull-out;
pull-off;
penetration resistance;
break-off.

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

2 Definitions

3 General

4 Applications

4.1 Comparative testing of concrete

4.2 Estimation of in situ concrete strength

4.3 Checking the uniformity of concrete

4.4 Testing repairs to concrete

4.5 Long-term monitoring

5 Choice of test method

6 Internal fracture test

6.1 General

6.2 Apparatus

6.3 Test procedure

6.4 Test results

6.5 Relationship between internal fracture force and strength of concrete

7 Pull-out test

7.1 General

7.2 Apparatus

7.3 Test procedure

7.4 Test results

7.5 Relationship between pull-out force and strength of concrete

8 Pull-off test

8.1 General

8.2 Apparatus

8.3 Test procedure

8.4 Test results

8.5 Relationship between pull-off stress and strength of concrete

9 Penetration resistance test

9.1 General

9.2 Apparatus

9.3 Test method

9.4 Test report

9.5 Relationship between penetration and strength of concrete

10 Break-off test

10.1 General

10.2 Apparatus

10.3 Test procedure

10.4 Test results

10.5 Relationship between break-off force and strength of concrete

11 Methods of establishing correlations between near-to-surface tests and strength

11.1 Introduction

11.2 Laboratory correlation

11.3 Site correlation

12 Assessment of structures

13 Report

13.1 General

13.2 Information to be included in the test report

Publication(s) referred to

BS 1881-207:1992

Testing concrete - Recommendations for the assessment of concrete strength by near-to-surface tests

Current

Published:

31 Jan 1992