TECHNICAL NOTE


Projects

Applications

Materials
  • no material found

Reference should be made to the general notes

Information source / date
Based on 2007 The Structural Design of Heavy Duty Pavements for Ports and other Industries 4th Edition and November 2009 Specification for Highway Works Series 800.

Compliance references
  • Manual of Contract Documents for Highway Works: Volume 1 (MCHW1), Specification for Highway Works, Series 800
  • The Structural Design of Heavy Duty Pavements for Ports and Other Industries
Technical references
  • BS 1377-2: 1990 Methods of test for soils for civil engineering purposes. Classification tests
  • BS EN 12457-3: 2002 Characterisation of waste Leaching Compliance test for leaching of granular waste materials and sludges Part 2: One stage batch test at a liquid to solid ratio of 10 l/kg for materials with particle size below 4 mm (without or with size reduction)
  • BS EN 13242: 2002+A1: 2007 Aggregates for unbound and hydraulically bound materials for use in civil engineering work and road construction
  • BS EN 14227-1: 2004 Hydraulically bound mixtures Specifications Part 1: Cement bound granular mixtures
  • BS EN 1744-3: 2002 Tests for Chemical Properties of Aggregates - Part 3: Preparation of Eluates by Leaching of Aggregates
  • EA NEN 7375: 2004. Leaching characteristics of solid (earth and stony) building and waste material. Leaching tests. Determination of the availability of inorganic components for leaching. Environment Agency (2005)
  • MCHW 1 (Manual of Contract Documents for Highway Works Volume 1), Specification for Highway Works. Highways Agency, Welsh Assembly Government, Transport Scotland and the Department of the Environment for Northern Ireland. The Stationery Office, London.
  • The Structural Design of Heavy Duty Pavements for Ports and Other Industries, 4th Edition (2007) Interpave. The British Precast Concrete Federation Ltd, Leicester.
  • WRAP (2004 and 2005). The quality protocols for the production of aggregates from inert waste in England, Scotland and Northern Ireland.
Composition requirements

No composition requirements are given in The Structural Design of Heavy Duty Pavements for Ports and other Industries. However, the Specification for Highway Works provides limits on the content of glass, wood and impurities by mass for Hydraulically bound mixtures (HBM). Further details can be found in the Application Hydraulically bound base.

Notes:
1. The limits for wood, glass and other impurities (Class X) have been set to encourage the use of processed recycled aggregates and aggregates from secondary sources. However, there are opportunities on many schemes to use mixtures with much higher proportions of secondary materials. If a particular source is available on or adjacent to the site it should be investigated as part of the site investigation. Where a possible source is known it can be tested to assess the construction and environmental risks associated with its use as part of the site investigation.
2. Higher limits are applicable if agreed with the Overseeing Organisation.
3. Clause 710 of the MCHW1 requires that recycled aggregates are produced in accordance with the ‘Quality Protocol for the production of aggregates from inert waste’ and the ‘Producers’ compliance checklist’ published by Waste and Resources Action Programme (WRAP). The results of all quality control checks carried out by the Contractor shall be compiled in accordance with the procedure set down in the above document and with those in Clause 710. These shall be delivered promptly to the client on request. For further information refer to the WRAP quality protocols for the production of aggregates from inert waste and the WRAP quality protocol checklists and guidance notes for producers, specifiers and purchasers of sustainable aggregates.

Grading requirements

The particle size should be determined by sieving method of BS 812-103

BS Sieve size (mm)
CBM1
CBM2
CBM3 and CBM4
Percentage passing by mass
-
Nominal maximum size
40 mm
20 mm
50
100
100
100
-
37.5
95
95-100
95-100
100
20
45
45-100
45-80
95-100
10
35
35-100
-
-
5
25
25-100
25-50
35-55
2.36
-
15-90
-
-
600
8
8-65
6-30
10-35
300
5
5-40
-
-
150
-
-
0-8 (0-10 for crushed rock fines)
0-8 (0-10 for crushed rock fines)
75
0
0-10
0-5
0-5


Notes:
1. CBM 1-4 have been superseded by a range of Hydraulically bound mixtures (HBM) within Series 800 of the Highways Agency’s Specification for Highways Works (SHW). The CBM 1-4 specification contained aggregate requirements separate to those stated in the revised version of the SHW. A contractor intending to use a HBM in this instance should ensure that the specific performance requirements for CBM 1-4 are met.

Physical properties requirements

All base materials shall require approval, by performance testing, in accordance with Part 2 of The Structural Design of Heavy Duty Pavements for Ports and other Industries.

Within The Structural Design of Heavy Duty Pavements for Ports and other Industries, aggregates for use in CBM2 must comply with the requirements shown in the table below.

PropertyTest method
Acceptable limits

Lower

Upper

5% fines valueBS 812-111

50 kN

-



The Structural Design of Heavy Duty Pavements for Ports and other Industries states that the aggregates must comply with the requirements of the 1991 edition of the SHW, which has been superseded by the November 2009 edition. The Specification for Highway Works provides specific information related to the range of Hydraulically bound mixtures (HBM). Further details can be found in the Application Hydraulically bound base.

Chemical properties

No restrictions on chemical properties are specified. However, in certain circumstances, the Environment Agency in England and Wales, (or their equivalent in Scotland and Northern Ireland) will require that the construction activities will not lead to contamination of ground or surface waters due to leaching or spillages. For this reason you are advised to discuss, as a matter of routine, your intended application with the relevant regulatory authority.

Assessment of the leaching potential is likely to involve laboratory testing to BS EN 1744-3: 2002, and/or BS EN 12457-3: 2002, and/or EA NEN 7375:2004. In order to correctly assess acceptability, the test results will need an appropriate interpretation, which may take allowance of leaching processes in situ as opposed to in the laboratory. For further information on these issues download the Environmental Information Sheet.

General notes

1. The Structural Design of Heavy Duty Pavements for Ports and other Industries refers to the 1991 edition of the SHW and BS 5328:2. The 1991 edition of the SHW has been superseded by the November 2009 SHW. BS 5328:2 has been superseded by BS 8500-1, BS8500-2 and BS EN 206-1. Within Series 800 of the SHW further requirements, listed below, are given.
2. CBM 1-4 have been superseded by a range of Hydraulically bound mixtures (HBM) within Series 800 of the Highways Agency’s Specification for Highways Works (SHW). The CBM 1-4 specification contained aggregate requirements separate to those stated in the revised version of the SHW. A contractor intending to use a HBM in this instance should ensure that the specific performance requirements for CBM 1-4 are met.
3. Aggregates for hydraulically bound mixtures (HBM) shall conform to BS EN 13242.
4. HBM can contain up to 40% recycled glass
5. The recycled and secondary aggregates listed have a specific or a general provision for use within the Specification for Highway Works, and may be used as long as these materials meet the required properties for aggregates given below.

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revised: 19 Feb 2010

Important warning

The information set out above is only concerned with the technical aspects of construction and is of a general nature only and not intended to be relied upon in specific cases.

It is derived from currently available UK Standards and Specifications applicable at the time of writing. Reference should be made to the relevant Standards and Specifications applicable at the time of writing and you should seek and rely upon expert professional advice on specific issues.

The information does not take account of environmental issues which you should discuss as a matter of routine with the regulatory authorities (the Environment Agency in England and Wales, the Scottish Environment Protection Agency in Scotland and the Department of the Environment in Northern Ireland).

Consequently, the information is provided only on the condition that WRAP and their sub-contractors will not be liable for any loss, expense or damage arising from your use or application of such information. See clause 3 of our Terms and conditions.