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 20-2 Section MH:1996 Asphalt base and surfacing First revision Part 2 : Project specification, Portion 2 Section MH Contents Page 1 Essential pro
4、ject specification clauses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2 Essentialdata 1 3 Additionalclauses . 1 3.1 General . 1 3.2 Normalprojects . l 3.2.1 Typeofaggregate . l 3.2.2 Sandequivalentvalue l 3.2.3
5、Shapeofaggregates . 1 3.2.4 Narrowstrips . 2 3.2.5 Trialsections . :. 2 3.2.6 Joints . “ 2 3.2.7 Mixdesign 2 3.2.8 Densitytesting 2 3.3 Prestigeprojects 2 3.4 Subeconornic projects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . .
6、 . . . . . . . . . . 2 This section of the code supersedes SABS 0120-2 : Section MH:1981 Approved by the PRESIDENT OF THE SOUTH AFRICAN BUREAU OF STANDARDS CODE OF PRACTICE SABS 0120-2 : Section MH:1996 SABS 1200 MH : Asphalt base and surfacing NOTES 1) Number the PSMH clauses in portion 2 of the pr
7、oject specification in the sequence in which the clauses to which they relate appear in SABS 1200 MH. 2) The clause number(s) given in brackets at the beginning or after the heading of a clause idare, unless otherwise stated, the number(s) of the relevant clause(s) of SABS 1200 MH. 1 Essentlaf proje
8、ct specification clauses Certain subclauses of the specifications refer to requirements that must be stated in the project specification. Set out as indicated below suitable clauses in portion 2 of the project specification, to provide the essential information. a) (3.5.2) Specify whether dolomite,
9、felsite or norite may be used (see also 3.2.1). b) (5.2) Specify whether a prime coat is required. c) (5.4) Specify whether a tack coat is required. d) (5.5.2) Where open-graded asphalt is required, specify the composition and voids. (See 2.3.1 and 2.5 of section MH of SABS 0120-3). e) (6.3.3) Speci
10、fy the width of base and surfacing unless the information is given on the drawings. 2 Essential data The availability of certain essential data could affect the prices tendered. Except where such data have been given in the schedule or in the tender drawings, set out suitable clauses covering items
11、such as the following, in portion 2 of the project specification: (Clause 1) Specify which type of asphalt is to be used. (3.1) Specify which type of prime is to be used. (3.4) Specify which type and grade of tar are to be used or which grade of bitumen is to be used. (3.5.8 and 4.5) Specify whether
12、 pre-coated chips are to be used and, if so, specify the size of stone to be used. (5.3) Specify whether a curing coat is required. (5.5.6) Specify whether a mineral filler is required. (5.9) If required, specify joints at an angle other than a right angle to the centre-lines. Additional clauses 3.1
13、 General Where it is necessary to amplify or otherwise to vary the terms of SABS 1200 MH to render them suitable for use in projects to be carried out in particular locations or under particular circumstances, include suitable PSMH clauses in portion 2 of the project specification to deal with matte
14、rs in addition to those covered by clauses 1 and 2. 3.2 Normal projects NOTE - To meet requirements imposed by various norms of economic development, projects are classified as normal, prestige, subeconomic, and labour-based projects (see clause 4 of the Introduction to SABS 0120-3). 3.2.1 Type of a
15、ggregate (3.5.2) State whether crushing of dolomite, felsite or norite is permitted. (Special circumstances or local experience might require or permit the use of one or more of these types of aggregate.) 3.2.2 Sand equivalent value (3.5.5) Amend the sand equivalent value as required. 3.2.3 Shape of
16、 aggregates The flakiness index requirements of the various local authorities are dependent on the shape of the aggregate that is most readily available in the area. In general, designs are based on the flakiness index that is most practicable and once the index has been established, the constancy w
17、ith which the contractor adheres to the specified flakiness index is of more significance than the actual index chosen. SABS 01 20-2 Section MH:l996 Asphalt base and surfacing First revision 3.2.4 Narrow Strips (4.4) Where the project reqlires that strips of width less than 2,5 m be paved, include a
18、 project specification clause in terms of which a paver as specified in 4.4 of SABS 1200 MH is not to be used for such strips, because this would be an expensive way of paving them. 3.2.5 Trial sections (5.5) Where the size of the project permits or circumstances require, include provision for layin
19、g trial sections as follows (NOTE - The intention of this clause is to prevent experimentation by the Contractor on the permanent work): PSMH 1.1 Construction of trial sections Before the Contractor commences the construction of any asphalt base or surfacing, he shall demonstrate, by laying a trial
20、section of length at least 100 m, that the equipment and prccesses that he proposes to use will enable him to construct the particular asphalt layer in accordance wilh the specified requirements. Only when such a trial section has been satisfactorily laid and finished, and is found to comply with th
21、e specified requirements, will the Contractor be allowed to commence with construction of the permanent work. Should the Cortractor make any alteration in the methods, processes, equipment or materials used, or should the work consistently fail to comply with the applicable requirements of the speci
22、fications, thct Engineer inay require that further trial sections be laid and tested before he allows the Contractor to continue with the permanent work. Trial sections sliall be laid where indicated by the Engineer. The Contractor shall prepare the surface can which a trial section is to be laid an
23、d shall also, if required, remove the trial section after completion and acceptably restore the surface on which it was constructed. Provision is ma,de in the schedule for payment for the first trial section, but subsequent trial sections shall be constructed at the Contractors expense. PSMH 1.2 Mea
24、surement and payment Trial sections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Unit: m* The rate shall cover the cost of priming as in 8.4.1 of SABS 1200 MH and the asphalt base tor surfacing, as the case may be, as in
25、8.4.2 of SABS 1200 MH. It shall also include the application of pre-coated chips (if applicable). 3.2.6 Joints (5.9) If required, specify a) an alternative method of cutting joints, b) the plan angle at hich transverse joints are to be made, and c) the positions of longitudinal joints where they do
26、not coincide with the edges of traffic lanes. 3.2.7 Mix design (7.1) If required, specify a period other than 3 weeks before the programmed starting or delivev date for the submission of the mix design. (The period chosen should be based on practical considerations where the supplier is a commercial
27、 supplier whose aggregate stockpiles rnove quickly, because the test results might then not be representative of the aggregate finally used .) 3.2.8 Density testing (7.2.4) Where acceptable, include provision for the use of approved and suitably calibrated devices that incorporate radioactive isotop
28、es for density testing. 3.3 Prestige projects Set out the requirements for special paving plant and construction processes for asphalt bases that are to carly exceptional loads and, in addition, in the case of a) surfaces carrying heavy traffic, and b) prestige surfacing, specify Degree of Accuracy I for tolerances and surfacing. 3.4 Subeconomic projects SABS 1200 MH covers a type of construction not generally warranted for subeconomic projects. sabs pta
