SANS 10120-3 M-1996 Code of practice for use with standardized specifications for civil engineering construction and contract documents Part 3 Guidance for design Section M Roads (.pdf

1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA

2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any

3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. SABS 01 20-3 Section MA996 Roads (general) Part 3 : Guidance for design Section M Contents Page 1 Pre-tenderconsiderations 1 . 1 1 Investigations and adm

4、inistration 1 . 1 . 1 1 Selection of grade and properties of single-sized crushed aggregate . 1 . . . 1 1 2 Polished stone value 1 . . 1 1 3 Average least dimension (ALD) of aggregate 1 . . 1 1 4 Statistical judgement plan 1 . . . 1 1 5 Treated aggregate for pavement layer 1 1.1.6 Sand . 1 . 1.2 Doc

5、umentation 1 1.2.1 Road usage and traffic control terms 1 . 2 Designrequirements 3 . 2.1 Technical 3 . 2.2 Application of principles of cost norms 3 2.2.1 Principles . 3 2.2.2 Application of principles for enhancement without replacement . 3 . 2.2.2.1 General 3 . 2.2.2.2 Stages of enhancement 3 2.3

6、Minimum average relative cornpaction requirements and statistical testing . 3 2.4 Shape requirements 4 . 3 Applicability of other codes 4 . 4 Testprocedures 4 . 4.1 General 4 4.2 Ventertest 4 4.2.1 Scope 4 . 4.2.2 Apparatus 4 4.2.3 Preparation of aggregate 4 . 4.2.4 Testprocedure 4 . 4.2.5 Evaluatio

7、n 5 . 4.2.6 Classification 5 5 Quality control and other considerations . 5 Drawings M.3.1 . Weathering test apparatus 6 . M.3.2 Visual classification . 7 First Revision 24 June 1996 . This section of the code supersedes SABS 0120-3 : Section M:1981 I Approved by the PRESIDENT OF THE SOUTH AFRICAN B

8、UREAU OF STANDARDS CODE OF PRACTICE SABS 0120-3 : Section M:1996 SABS 1200 M : Roads (general) NOTE - The clause number(s) given at the beginning or after the heading of a clause istare, unless otherwise stated, the number(s) of the relevant clause(s) of SABS 1200 M. 1 Bre-tender csnsideratisns 1 .l

9、 Investlgatlons and admPnistratlon (See the sections of this part of the code relating to the standardized specifications that form part of the contract.) 1.1.1 Selection of grade and properties of single-sized crushed aggregate The inclusion cif grades 2 and 3 aggregate permits the use of cheaper l

10、ocal stone. However, the amount of dust allowed in grade 3 aggregate could cause problems with hot binders. This grade of aggregate should be used with emulsion to overcome or reduce the dust problem, An impact crusher tends to produce cubical chips. In certain instances a more flaky chip is conside

11、red desirable, for example a 6,7 mm chip in a double seal and single-sized aggregate reseal surfacing. 1 .l .2 Polished stone value The test method for determining polished stone value was revised in 1990. Before this date, polished stone values were determined in accordance with SABS method 848), b

12、ased on BS 812-3:1975). Currently the test method for polished stone value is based on BS 812-1 14:198g3). Tests done in accordance with SABS 1083) from July 1987 to December 1989, on aggregate from different sources have given results that vary from about 47 to 63. Tests done in accordance with BS

13、812 from January 1990 to November 1993, on aggregate from different sources have given results that vary from about 43 to 61. 1 .l .3 Average least dimension (ALD) of aggregate The specification of a minimum ALD for aggregate, e.g. 60 O/O of nominal stone size, ensures a reasonably cubical product.

14、However, this requirement can have significant cost implications in certain areas, owing to the limiting crushing characteristics of the local stone. 1 .l .4 Statistical judgement plan Acceptance control by means of a statistical judgement plan is not a requirement in terms of this specification unl

15、ess the contract document contains a specification or a project specification clause specifically stating that appendix B of SABS 1200 M shall apply, in which case, it will apply only to those properties for which it is specifically stated to apply (see 7.3.3 of SABS 1200 M). Where no such specifica

16、tion or project specification clause is included in the contract document, acceptance of road materials will be controlled by the absolute values given in the applicable specification. 1 .l .5 Treated aggregate for pavement layer Certain tests such as the Brushing test, Erosion test and Carbonation

17、test have been developed by CSIWDRTT, to determine the durabilitylerodability of stabilized pavement layers. 1.1.6 Sand Sand as defined in 2.2 of SABS 1200 M is required to be compacted to at least 100 O/o of modified AASHTO maximum density. Experience, particularly with aeolian sands, indicates tha

18、t depending on the percentage passing the 0,075 mm sieve (in the range 10 5% to 20 %) and also on the modified AASHTO maximum density value obtained, relative compactions higher than the specified value (e.g. for subbase: 95 %) can be achieved, but not reaching 100 %. For sandy materials in this int

19、ermediate range, the carrying out of trial sections to establish an achievable relative compaction might be necessary. 1.2 Documentation 1.2.1 Road usage and traffic control terms Ensure that the road usage and traffic control terms used in all documentation conform to the following, and have the me

20、anings given: Auxiliary lane: The portion of a roadway adjoining the travelled way and intended for parking, speed change, storage for turning, weaving, slow movement, and for other purposes supplementary to through traffic movement. 1) Polished - stone value of aggregates. 2) Testing aggregates - M

21、ethods for determination of mechanical properties. 3) Testing aggregates - Methods for determination of the polished-stone value. 4) Aggregates from natural sources - Aggregates for concrete. Barricade: A portable er fixed barrier used to close all or a portion of a travelled way to vehicular traffi

22、c. Barrier: Any structure intended to prevent access by vehicles or pedestrians. Barrier kerb: A kerb intended 90 prevent vehicles from leaving the roadway. Beam: A mound of rnalerial. Bollard: See Crash cushion. Boundary strip: A portion of a verge between a footway and an adjacent boundary. Buffer

23、: See Crash eushion. Bus: See Vehicle. Bus lane: A portion of a travelled way demarcated tor the specific use of buses. Bus way: A roadway intended for the sole use of buses and other authorized vehicles. Channdlzation: The use of islands and roadwzy markings to facilitate the flow of traffic. Crash

24、 cushian; bollard; buffer: A structure at the approach end of a safety zone, designed to defled or stop any vehicle that collides with it. Cycle lane: A portion of a roadway demarcated for the specific use of pedal cycles. Cyck path: A portion of land, outside a road reserve, reserved for the use of

25、 pedal cycles. Cycle way: A constructed portion of a travelled way for the use of pedal cycles. NOTE - A cycle way can be an extension of a footway and intended as a shared facility. Driveway: The constructed access across a footway to a private dwelling. Kerb: A longitudinally constructed projectio

26、n usually abutting either the surface of a roadway or a channel and of height up to 30Q mm above the planned finished surface of the roadway. (See also Barrier kerb and Mountable kerb.) Kerb opening: A gap in a barrier kerb, to allow vehicular access from a roadway to an adjacent erf. Level crossing

27、: The at-grade intersection of a roadway and a railway track. Loading bay: A constructed area that is adjacent to or part of a roadway and is demarcated and reserved solely for the loading and unloading of vehicles. Median: A longitudinal division between the travelled ways of separate roadways. Med

28、ian gap: An opening through a median, constructed for vehicular access between roadways. Mountable kerb: A kerb so designed as to permit vehicles to leave the travelled way. Outerllnner: Terms applicable to elements of a road reserve and descriptive of their respectwe posrtions in relation to its ce

29、ntre-line (inner being closer to the centre-line). Parking bay: An area constructed adjacent to or on a roadway and intended for the parking of vehicles. Parking lane: A portion of a roadway intended for the parking of a single line of vehicles. Pedal cycle: See Vehicle. Pedestrian: Any person on fo

30、ot. Pedestrian crossing: A transverse strip on a roadway, intended tor use by pedestrians in crossirlg the roadway and in regard to which the respective priorities of pedestrians and vehicles are ruled by order or regulation. Pedestrian entrance: A portion of a verge providing a constructed access f

31、or pedestrians between a roadway and the boundary. NOTE - A pedestrian entrance can include ramps for prams, wheelchairs, etc., and the constructed surface up to the boundary. Pedestrian ramp: A ramped access for pedestrians, onto an area adjacent to a roadway. Pedestrian refuge: A raised platform o

32、r guarded area so sited in a roadway as to divide the streams of traffic and to provide a safety area for pedestrians. Public road: As defined in the Road Traffic Ordinance. Refuge: A fully constructed and surfaced area reserved for emergency parking of vehicles outside the travelled way. Side strip

33、: The portion of a verge between a footway and the roadway. Traffic Island: An area designed to separate or direct streams of vehicular traffic. TrafFic Dane: A portion of the surfaced width of a travelled way, demarcated for the passage of a single line of vehicies. SABS 01 28-3 Section W1996 Roads

34、 (general) Traffic sign: A device mounted on a fixed or portable support and intended to convey a specific message by means of words or symbols to the drivers of vehicles on a roadway. Traffic signals: A system of different-coloured lights used for controlling the movement of traffic and pedestrians

35、. VehicDeibudpedal cycle: As defined in the Road Traffic Ordinance. Vehicle crossing: A constructed and surfaced area through a portion of a verge to allow vehicles to cross between a roadway and the boundary. Vehicle entrance: A portion of a verge providing a constructed access for vehicles between

36、 a roadway and the boundary. NOTE - A vehicle entrance can include openings in the kerbs and any constructed surface up to the boundary. 2 Design requirements 2.1 Technical Consult the relevant TRH) publication for guidance on all aspects of the design of roads. 2.2 Application of principles of cost

37、 norms (See 4.3 of the Introduction) 2.2.1 Principles The application of the principles of cost norms can be demonstrated for road construction more readily than for any other service. The fallowing considerations are applicable to a subeconomic road construction project: a) The initial earthworks s

38、hould be located, as far as possible, on the same location as might be adopted in due course for an enhanced economic standard of construction. b) The first enhancement should take the form of the addition of a selected subgrade surface. This should be followed in stages by the addition of the subba

39、se and eventually of the base and surfacing. c) River crossings should be effected by means of causeways that are provided initially at flood discharge points. Bridges and culverts will, in due course, enhance the standard. 2.2.2 Application of principles for enhancement without replacement 2.2.2.1

40、General The same set of standardized specifications can be used to cover the requirements for the whole of the range of middle and economic classes of construction, because the cost of construction is dependent on the location of the road and on the design of the controlled layers. The cost is, in a

41、ddition, more dependent on the quantity than on the physical properties and the method of placing and compacting of a particular readily available material. 2.2.2.2 Stages of enhancement The following stages of enhancement should be considered: a) The location, coupled with the width of the road sur

42、face and the consequent volume of earthworks to be removed, determines the cost of the earthworks portion of the road. bj The eafihworks and selected layer (see SABS 1200 DM“) that can take loads will give acceptable service if finished off with a gravel surface layer for which SABS 1200 DM“ also ma

43、kes provision. c) The subbase (see SABS 1200 ME) is a foundation layer that also provides a suitable wearing surface for a gravel road or for shoulders. Its load-carrying capacity can be varied by varying the thickness of the layer. d) The addition of the base (see SABS 1200 MFH) or SABS 1200 MFL) i

44、s the next stage of enhancement, and here again the designed thickness defines the load-carrying capacity of the road. e) The type and quality of the finished surface placed on top of the base provides still further scope for enhancement by the use of additional thickness or by selection of type or

45、both. f) Thus the same specifications cover a series of road types varying from lightly constructed gravel roads, through city streets, up to roads for high density traffic with a high frequency of heavy loads required for city thoroughfares, main roads, and throughways. 5) Technical recommendations

46、 for highways, published by the Committee of State Road Authorities. 6) Earthworks (subgrade). 7) Subbase. 8) Base (heavy pavement structures) (In course of preparation). 9) Base (light pavement structures). 2.3 Minimum average relative compactisn requlreamsnts and statistical testing (7.3.3) MOTE -

47、 Whsre the magnitude or nature of the works is such that the design engineer considers statistical c:ontsol of testing, tolerances or any other features necessary, give consideration to specifying a Statistical Judgemen! Plan as ndix B of SABS 1200 M. 2.3.1 Statistical testing requires that tests be

48、 carried out on samples obtained from test positions selected randomly from stratified sections and that the party carrying out the tests, whether he be the contractor or the engineer, establish the size of each lot and the number of samples and designate the tests that are to be carried out on thos

49、e samples. If the statistical analysis k being carried out by the contractor for purposes of his control of the works, ?e should select the lot size and the number of samples. If the siakistical analysis is required for control purposes by the engineer, the engineer sbould decide on the size of each lot and the number 21: samples that the contractor is %o lest and if these differ from those specified in appendix B of SABS 1200 M, he should ensure that the necessary amendments are made through the project specificatisn. 2.3.2 The minimum average rela!ive ons sp.dfied in 7.3.2 of SABS