1、 Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 30/11/2011 07:37, Uncontrolled Copy, (c) BSIg49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58
2、surfaces Code of practiceICS 91.060.30; 91.100.15 Screeds, bases and in situ floorings Part 4: Cementitious terrazzo wearingBRITISH STANDARDBS 8204-4:2004+A1:2011BS 8204-4:2004+A1:2011Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 30/11/2011 07:37, Uncontrolled Copy, (c) BSICommitteBrThCoThi
3、s British Standard was published under the authority of the Standards Policy and Strategy Committee on30 September 2004 BSI 2011First published October 1993 Second edition September 2004The following BSI references relate to the work on this British Standard:Committee reference B/507/6Draft for comm
4、ent 04/30055999 DCISBN 978 0 580 74241 511/30240639 DC;Contract Flooring Association Federation of Plastering and Drywall Contractors Federation of Resin Flooring Formulators and Applicators Mastic Asphalt Council Mortar Producers Association Limited National Federation of Terrazzo-Marble and Mosaic
5、 Specialists National Specialist Contractors Council Quarry Products Association Society of Chemical Industry Co-opted membersAmendments issued since publicationAmd. No. Date CommentsA1 31 July 2011 See forewordes responsible for this itish Standarde preparation of this British Standard was entruste
6、d by Technical mmittee B/507, Paving units, kerbs, screeds and in situ floorings, to Subcommittee B/507/6, Screeds and in situ floorings, upon which the following bodies were represented:Association of Concrete Industrial Flooring Contractors Association of Lightweight Aggregrate Manufacturers Briti
7、sh Cement Association Concrete Society BS 8204-4:2004+A1:2011 BSI 2011 Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 30/11/2011 07:37, Uncontrolled Copy, (c) BSIContentsPageCommittees responsible Inside front coverForeword ii1 Scope 12 Normative references 13 Terms and definitions 14 Exchan
8、ge of information and time schedule 25 Materials 36 Design considerations 47 Work on site 88 Inspection and testing of flooring 129 Cleaning and maintenance 13Annex A (normative) Methods for assessing levels and surface regularity 14Bibliography 20Figure A.1 Stainless steel slip gauges for checking
9、surface regularity 14Table 1 Minimum thickness of terrazzo flooring relative to size of aggregate 7Annex B (normative) Determination of slip resistance of pedestrian surfacesby the ramp/trolley method, alternatively known as the roller coaster method 15Figure B.1 Trolley and rampFigure B.2 Calculati
10、on to determine the coefficient of frictionor the equivalent slip resistanceTable B.1 Reproducibility161818iBS 8204-4:2004+A1:2011ii Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 30/11/2011 07:37, Uncontrolled Copy, (c) BSIBS 8204-4:2004+A1:2011 supersedes BS 8204-4:2004, which is withdrawn
11、.Amendment A1 introduces the following principal change. Insertion of Annex B on determination of slip resistance of pedestrian surfaces by the ramp/trolley method, alternatively known as the roller coaster method.Terrazzo flooring can provide a hard, durable surface which is easy to clean. The term
12、 “sand” is used throughout this document as this is the common terminology in the UK screeding industry although recent European Standards use the term “fine aggregate”.The other parts of BS 8204 are the following: Part 1:2003, Concrete bases and cement sand levelling screeds to receive floorings Co
13、de of practice; Part 2:2003, Concrete wearing surfaces Code of practice; Part 3:2004, Polymer modified cementitious levelling screeds and wearing screeds Code of practice; Part 5:2004, Mastic asphalt underlays and wearing surfaces Code of practice; Part 6:2001, Synthetic resin floorings Code of prac
14、tice; Part 7:2003, Pumpable self smoothing screeds Code of practice.As a code of practice, this British Standard takes the form of guidance and recommendations. It should not be quoted as if it were a specification and particular care should be taken to ensure that claims of compliance are not misle
15、ading.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.Summary of pagesThis document comprises a front cover, an inside front cov
16、er, pages i and ii, pages 1 to 20, an inside back cover and a back cover.The BSI copyright notice displayed in this document indicates when the document was last issued.The start and finish of text introduced or altered by Amendment No. 1 is indicated in the text by tags !“. Minor editorial changes
17、are not tagged.ForewordThis part of BS 8204 has been prepared by Subcommittee B/507/6. BSI 2011BS 8204-4:2004+A1:2011Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 30/11/2011 07:37, Uncontrolled Copy, (c) BSI1 ScopeThis part of BS 8204 gives recommendations for the materials, design, work on
18、 site, inspection and testing, and cleaning and maintenance for in situ cementitious terrazzo flooring. It is intended for terrazzo contractors, specifiers, builders, designers and main contractors. It gives recommendations for in situ terrazzo flooring applied as a wearing surface on a concrete bas
19、e or screed.NOTE This part of BS 8204 is intended to be read in conjunction with BS 8204-1.2 Normative referencesThe following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition
20、 of the referenced document (including any amendments) applies.BS 1521:1972, Specification for waterproof building papersBS 4483:1998, Steel fabric for the reinforcement of concrete.BS 6100-1, Glossary of building and civil engineering terms Part 1: General and miscellaneous.BS 6100-6, Glossary of b
21、uilding and civil engineering terms Part 6: Concrete and plaster.BS 7976-2, Pendulum testers Part 2: Method of operation.BS 8204-1, Screeds, bases and in situ floorings Part 1: Concrete bases and cement sand levelling screeds to receive floorings Code of practice.BS 8204-3, Polymer modified cementit
22、ious levelling screeds and wearing screeds Part 3: Code of practice. BS EN 197-1, Cement Part 1: Composition, specifications and conformity criteria for common cements. BS EN 934-2, Admixtures for concrete, mortar and grout Part 2: Concrete admixtures Definitions, requirements, conformity, marking a
23、nd labelling.BS EN 12878, Pigments for the colouring of building materials based on cement and/or lime Specifications and methods of test.BS EN 13139, Aggregates for mortar.BS EN 13318, Screed material and floor screeds Definitions.BS EN 13813, Screed material and floor screeds Screed material Prope
24、rties and requirements. Hospital Technical Memorandum No. 2, Anti-static precautions: Flooring in Anaesthetizing Areas, London: The Stationery Office, 19771).3 Terms and definitionsFor the purposes of this part of BS 8204, the terms and definitions given in BS 6100-1, BS 6100-6, BS EN 13318 and the
25、following apply.3.1 base building element that provides the support for a screed and floor finishes3.2 flooring uppermost fixed layer of a floor that is designed to provide a wearing surface3.3 screed layer of material laid in situ, directly onto a base, bonded or unbonded, or onto an intermediate l
26、ayer or insulation layer, for one or both of the following purposes:1 to obtain a defined level; to carry the final flooring1) Obtainable from The Stationery Office. BSI 2011BS 8204-4:2004+A1:2011Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 30/11/2011 07:37, Uncontrolled Copy, (c) BSI3.4 b
27、ase course first layer of marble or other natural stone aggregate mixture applied to the screed3.5 terrazzo mixture of marble or other natural stone aggregates, with Portland cement, which is ground after setting to expose the aggregate and provide a smooth hard-wearing finishNOTE 1 The mixture may
28、also include suitable glass aggregate.NOTE 2 Terrazzo incorporates colouring pigments where necessary.4 Exchange of information and time scheduleNOTE This clause deals with the exchange of information and time schedule for the whole floor, including bases and screeds.4.1 GeneralIt is essential that
29、consultations and exchange of information between all parties concerned with the building operations are arranged at an early date. This will enable each party to have full knowledge of the particulars of the work so that they can cooperate in producing the conditions required to complete a satisfac
30、tory job.4.2 Exchange of informationIt is essential that the designer provides in good time all relevant information to those responsible for laying the flooring and to others whose work might be affected, including whichever of the following are applicable:a) description, situation and address of s
31、ite and means of access;b) those conditions of contract which could practically affect this particular work;c) degree of weather protection afforded by the structure;d) location and area of in situ terrazzo flooring to be laid;e) age and nature of the base, including information about the previous u
32、se of the floor which could impair adhesion and any preparatory treatment required;f) survey of the base including surface regularity and departure from datum;g) nature and extent of necessary repairs and other preliminary work;h) thickness of floor and flooring;i) finished floor level, falls and ma
33、ximum permissible departure from datum in each location;j) specification including proportions and type, colour and size of aggregate of flooring to be laid;k) class of surface regularity of base (see BS 8204-1:2003, Table 5);l) slip resistance;m) type of damp-proofing and insulation;n) type and thi
34、ckness of levelling screed;o) category of in situ crushing resistance (soundness) required;p) any work consequent upon services passing through the floor;q) treatment of joints;r) treatment of channels;s) treatment of skirtings;t) treatment of junctions with adjacent floors and floorings;2 BSI 2011u
35、) type of finish of base;v) any special requirements related to underfloor heating;w) minimum time intervals between stages of work and the application of heat in the building;BS 8204-4:2004+A1:2011Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 30/11/2011 07:37, Uncontrolled Copy, (c) BSIx)
36、date for the completion of the base to receive the terrazzo;y) dates for the start and completion of various sections of the floor;z) details of any compliance testing required; aa) any other requirements for materials, design or work on site.4.3 Time scheduleIn considering the schedule, in addition
37、 to the usual intervals between commencement and completion of work by the various trades involved, allowances should be made for the following:a) completion of the building envelope to allow construction of a levelling screed and terrazzo wearing surface protected from rain, wind and sun;b) delays
38、due to frost and cold weather;c) curing and drying of the base concrete before the screed and flooring is laid, where applicable;d) period of protection of the completed floor from damage by other trades, including restriction of access.5 Materials5.1 Cement5.1.1 Cement for screedsThe cement for scr
39、eeds should be grey Portland cement conforming to at least CEM 1 class 42.5N of BS EN 197-1:2000.5.1.2 Cement for terrazzo flooringThe cement for the terrazzo flooring should be grey or white Portland cement conforming to at least CEM 1 class 42.5N of BS EN 197-1:2000.WARNING 1 When Portland cement
40、is mixed with water, or even becomes damp, alkalis are released that can be harmful to the skin. The effect depends on the length of contact, any abrasion, the individual and the part of the body involved. Suitable protective clothing should be worn. If eyes are affected, they should be washed out w
41、ithout delay and medical advice sought.WARNING 2 Cement mortar and concrete might until set cause both irritant and allergic contact dermatitis. Irritant contact dermatitis is due to a combination of the wetness, alkalinity and abrasiveness of the constituent material. Allergic contact dermatitis is
42、 caused mainly by the sensitivity of an individuals skin to hexavalent chromium salts.5.2 Aggregates5.2.1 Aggregates for screedsAggregates for screeds should conform to BS 8204-1:2003, 5.3.5.2.2 Aggregates for terrazzo flooringAggregates for terrazzo wearing surfaces should be crushed marble, natura
43、l stone or glass, should be angular as distinct from elongated and flaky, and should be free from fines and dust. Aggregates should be washed and single-sized between 3 mm and 25 mm and may be used individually or mixed.NOTE The size of aggregate for the base course can range from 2 mm to 6 mm, whil
44、st larger aggregate, generally from 9 mm to 15 mm, can be spread by hand on top of the base course, depending on the decorative effect required. See 7.10.Sands should conform to BS EN 13139:2002 0/4 mm (MP) category 1.5.2.3 Deleterious material3Aggregates should not contain any deleterious material
45、in sufficient quantity to affect adversely the integrity of the surface finish. For example, coal, lignite and iron pyrites in the aggregate can cause “pop-outs”. Some aggregates exhibit higher than average drying shrinkage and should not be used as they give rise to a greater risk of cracking (see
46、BRE Digest 357 1 and BS EN 1367-4). BSI 2011BS 8204-4:2004+A1:2011Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 30/11/2011 07:37, Uncontrolled Copy, (c) BSI5.3 PigmentsPigments should conform to BS EN 12878. Other pigments may be used by agreement between the parties concerned, although tho
47、se not conforming to BS EN 12878 could be subject to fading.5.4 AdmixturesAdmixtures should conform to BS 934-2. The following admixtures may be used, on occasion, in the laying of the screed. They are rarely necessary or encountered in the terrazzo flooring.a) Air-entraining. Air-entraining admixtu
48、res entrain a small amount of fine air bubbles that help to reduce “bleeding” of free water and improve the finished surface of the concrete base or screed. An excessive amount of entrained air should be avoided as this can reduce the strength.b) Water reducing. Water reducing admixtures may be used
49、 to increase consistence and reduce the water content otherwise required in the mix. They may also entrain a small quantity of air and cause retardation of setting.c) Superplasticizing. Superplasticizing admixtures greatly increase consistence at normal water contents for a limited period to produce “flowing concrete” which needs little or no compaction. Alternatively they may be used as high range water reducing admixtures.d) Accelerating. Accelerating admixtures may be used to accelerate the rate of setting and hardening
