BS-7533-4-1998.pdf

| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS 7533 : Part 4 : 1998 ICS 93.080.20 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Pavements constructed with clay, natural stone or concrete pavers Part 4. Code of practice for the construction of pavements of precast concrete flags or natural stone slabs Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 14:54:01 GMT+00:00 2006, Uncontrolled Copy, (c) BSI This British Standard, having been prepared under the direction of the Sector Board for Building and Civil Engineering, was published under the authority of the Standards Board and comes into effect on 15 April 1998 BSI 1998 The following BSI references relate to the work on this standard: Committee reference B/507 Draft for comment 96/103818 DC ISBN 0 580 28652 5 BS 7533 : Part 4 : 1998 Amendments issued since publication Amd. No.DateText affected Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Committee B/507, Paving units and kerbs, upon which the following bodies were represented: Brick Development Association British Cement Association British Ceramic Research Ltd. British Precast Concrete Federation Ltd. Cementitious Slag Makers' Association County Surveyors' Society Department of Transport (Highways Agency) Institution of Civil Engineers Instituton of Highways and Transportation Interlay, the Association of Block Paving Contractors Interpave the Concrete Block Paving Association Landscape Institute Society of Chemical Industry Stone Federation The following bodies were also represented in the drafting of the standard, through subcommittees and panels: British Civil Engineering Test Equipment Manufacturers' Association Institution of Structural Engineers National Federation of Clay Industries Ltd. National Paving and Kerb Association Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 14:54:01 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7533 : Part 4 : 1998 BSI 1998i Contents Page Committees responsibleInside front cover Forewordii Code of practice 1Scope1 2References1 3Definitions1 4Preparation of the sub-layer1 5Preparation of existing bases as the sub-layer3 6Installation of units3 Annexes A(informative) Reinstatement of flag and slab areas7 B(informative) Recommended typical layouts7 Tables 1Compaction plant for sub-layer2 2Materials for sub-layer construction2 3Minimum time between finishing sub-layer and laying products2 4Grading for laying course sand and jointing sand6 5Thickness of laying course6 Figures 1Typical section3 2Typical ways of cutting flags4 3An example of a ramped crossing and over-run area using small element flags or slabs5 B.1An example of a ramped crossing8 B.2An example of a dropped crossing8 B.3An example of a runout corner9 B.4An example of a new town corner9 List of referencesInside back cover Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 14:54:01 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ii BSI 1998 BS 7533 : Part 4 : 1998 1)In preparation. Foreword This Part of BS 7533 has been prepared by Technical Committee B/507, Paving units and kerbs. It supersedes BS 7263 : Part 2 : 1990 which is withdrawn. BS 7533 will be published in the following Parts: Part 11)Guide for the structural design of heavy duty pavements constructed of clay pavers or precast concrete paving blocks Part 21)Guide for the structural design of lightly trafficked pavements constructed of clay pavers or precast concrete paving blocks Part 3Code of practice for laying precast concrete paving blocks and clay pavers for flexible pavements Part 4Code of practice for the construction of pavements of precast concrete flags or natural stone slabs Part 51)Guide for the design of pavements (other than structural aspects) Part 61)Code of practice for construction of pavements Ð kerbs, channels and edgings Part 71)Code of practice for the construction of pavements of natural stone setts Part 81)Guide for the structural design of lightly trafficked pavements of precast concrete flags and natural stone slabs BS 7533 : 1992 will be withdrawn on the publication of Parts 1 and 2. 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 10, an inside back cover and a back cover. Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 14:54:01 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BSI 19981 BS 7533 : Part 4 : 1998 Code of practice 1 Scope This Part of BS 7533 gives recommendations for laying precast concrete flags conforming to BS 7263 : Part 1 : 1994 Precast concrete flags, kerbs, channels, edgings and quadrants : Part 1 : Specification and natural stone slabs, intended for use in the construction of carriageways, footways, pedestrian areas and pavements. 2 References 2.1 Normative references This Part of BS 7533 incorporates, by reference, provisions from specific editions of other publications. These normative references are cited at the appropriate points in the text and the publications are listed on the inside back cover. Subsequent amendments to, or revisions of, any of these publications apply to this Part of BS 7533 only when incorporated in it by updating or revision. 2.2 Informative references This Part of BS 7533 refers to other publications that provide information or guidance. Editions of these publications current at the time of issue of this standard are listed on the inside back cover but reference should be made to the latest editions. 3 Definitions For the purposes of this Part of BS 7533, the definitions given in BS 7263 : Part 1 and BS 6100 : Part 2 apply together with the following. 3.1 edge restraint Device which serves to prevent lateral movement of the products and to prevent loss of material from the bedding layer. 3.2 joint width The distance between two adjacent units or units and restraint. 3.3 laying face Working edge of the surface course at which laying of products takes place. 3.4 laying course Layer of material on which the units are laid. 3.5 roadbase One or more layers of material above the sub-base that is a structural element of a composite pavement. 3.6 sub-base One or more layers of material between the roadbase and/or laying course and subgrade. 3.7 subgrade The part of the soil, natural or constructed, that supports the loads transmitted from the overlying pavement. 3.8 surface course Layer of precast concrete or natural stone flags which acts as the wearing surface and forms part of the structure of the paving. 3.9 sub-layer Layer below the laying course which may include either or both sub-base and roadbase layers above the subgrade. 4 Preparation of the sub-layer 4.1 Excavation All topsoil and unsuitable material should be excavated from the area to be paved and the ground should be reduced to the specified level. Any soft spots or loose spots should be replaced with sound, properly compacted and inert material, or with foamed concrete. NOTE. Replacement material should have properties similar to the ground adjacent to the soft spot. 4.2 Subsoil drainage Any subsoil drainage required beneath the pavement should be completed before commencing backfilling. 4.3 Backfilling All trenches within the pavement area should be backfilled in layers, fully compacting each layer before placing the next, so that the resulting reinstated ground has a similar load bearing capacity to that of the undisturbed ground (see also annex A.) Guidance on the choice of compaction plant and the minimum number of passes for a particular compacted layer thickness is given in table 1. NOTE. Further information is given in the requirements of the Highway Authorities and Utilities Committee (HAUC) Specification for the reinstatement of openings in highways.1 4.4 Drainage of laying course using natural ground as the sub-layer 4.4.1 Any drainage required to protect the laying course from saturation should be completed before placing the laying course. Drainage inlets should be protected from ingress of laying course material, e.g. by using filter fabric. 4.4.2 The ground should be levelled so that the required surface level and laying course thickness, including tolerances, are achieved. 4.5 Construction of the sub-layer using imported material 4.5.1 The sub-layer material should be placed in layers not exceeding 150 mm in thickness or twice the nominal maximum aggregate size, whichever is the greater, until the specified thickness is reached. Each layer should be fully compacted before the next layer is placed. Suitable imported materials for sub-layer construction are given in table 2. Guidance on the choice of compaction plant and the minimum number of passes for a particular compacted layer type and thickness is given in table 1. The sub-layer should have a close-textured surface after compaction. Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 14:54:01 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 2 BSI 1998 BS 7533 : Part 4 : 1998 Table 1. Compaction plant for sub-layer Type of compaction plantMassMinimum number of passes for compacted layer thickness 100 mm150 mm Vibrating plate1400 kg/m2to 1800 kg/m2 1)6Not suitable 1800 kg/m2to 2100 kg/m2 1)48 Vibrating roller700 kg/m to 1300 kg/m2)12Not suitable 1300 kg/m to 1800 kg/m2)512 Engine driven vibro-tamper50 kg to 65 kg48 65 kg to 75 kg36 Over 75 kg24 1) Unit area beneath the base plate. 2) Unit width of roller. Table 2. Materials for sub-layer construction MaterialClause reference in Specification for Highway Works, 6th Edition, Department of Transport2 Granular sub-base material type 1803 (except that 100 % should pass a 37.5 mm sieve) Granular sub-base material type 2804 Cement-bound material category 1 (CBM 1)1036 Cement-bound material category 2 (CBM 2)1037 Cement-bound material category 3 (CBM 3)1038 Wet-lean concrete1030 Concrete grade C25P in accordance with BS 5328Ð Table 3. Minimum time between finishing sub-layer and laying the surface course Sub-base material (see table 1) Minimum time for surface course bedded with maul Minimum time for surface course bedded with vibrator hh Natural ground00 Granular sub-base material type 1 00 Bitumen-bound material00 Cement-bound material categories 1, 2 or 3 072 (at ambient temperatures above 4 8C) Wet-lean concrete Structural concrete 40 (at ambient temperatures above 4 8C) 72 (at ambient temperatures above 4 8C) 4.5.2 The sub-layer should be levelled so that the required surface level and laying course thickness, including tolerances, are achieved. 4.5.3 Where the sub-layer contains cement and is not to be covered by another pavement course within 2 h, it should be protected from moisture loss, e.g. by covering with plastic sheeting. If a curing membrane or compound is used, the manufacturer's instructions should be followed. The appropriate minimum time given in table 3 should be allowed to elapse before starting to lay the surface course. Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 14:54:01 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BSI 19983 BS 7533 : Part 4 : 1998 ? ? Sub-layerSubgrade Laying coursePrecast flag or slabEdge restraint Figure 1. Typical section 5 Preparation of existing bases as the sub-layer 5.1 Where a surface course is to be laid over existing roads or similar types of construction, corrections to existing levels may be required. 5.2 The existing surface water drainage levels should be checked to ensure that the drains will continue to function after adjustment of levels. Any new drains should be installed in accordance with 4.4.1. 5.3 Any excess material should be removed to allow installation of a bedding course of 25 mm thickness when compacted. Levels should be built up using suitable materials (see table 2) and compacted as described in 4.5.1. 5.4 The base should be levelled so that its surface level does not differ from the design level by more than ±10 mm. 5.5 Where any regulating layer containing cement is not to be covered by another pavement course within 2 h, it should be protected from moisture loss, e.g. by covering with plastic sheeting. A bituminous emulsion membrane can be used in accordance with the manufacturer's instructions. 5.6 The sub-base should be levelled so that its surface level does not differ from the design level by more than 10 mm. 5.7 The appropriate minimum time given in table 3 should be allowed to elapse before starting to lay the surface course. 6 Installation of units 6.1 Uniform support The laying course should provide a uniform support for the flags and slabs and should not be used as a means of correcting the tolerances or any minor surface irregularities in the sub-base. 6.2 Edge restraints Edge restraints should be capable of preventing the loss of laying course material and sideways movement of flags and slabs, and of supporting design traffic loads, including constructional loads, before the laying material and the flags and slabs are laid (see figure 1). Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 14:54:01 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 4 BSI 1998 BS 7533 : Part 4 : 1998 6.3 Cutting flags and slabs Wherever possible, cutting flags or slabs should be avoided, e.g. by using other sizes of the same thickness. If more than 25 % of the flag or slab has to be notched, the remaining shape (from the internal corner of the cut-out to the external corner of the flag or slab) should be cut as shown in figure 2, (see also annex B). a) Example 1 b) Example 2 45° desirable Figure 2. Typical ways of cutting flags Concrete infill around an obstruction should be kept to a minimum. It should not exceed 25 mm in width, and should be the full depth of the flag or slab. Where concrete infill is used, it should have a maximum aggregate size of 10 mm and a concrete strength conforming to C25 as specified in BS 5328. NOTE. Careful selection of material or pigments may be necessary to achieve an adequate colour match. Proper curing of the concrete is essential. 6.4 Laying details It is recommended that flags or slabs are bonded (see figure 3). Where concrete paving blocks are used to form the bond between flags, their differing dimensions and tolerances may require the use of wider joints. Flag and slab laying on slopes should commence from the bottom upwards whene