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 MFL:l996 Ease (light pavement structures) Part 2 : Project specification. Portion 2 Section MFL Contents Page 1 Essential project &x
4、ifieation clauses . 1 2 Essentialdata 1 3 Addilonalclauses . 1 . 3.1 General 1 3.2 Normalprojects . 1 3.2.1 Physical properties of natural gravels . 1 3.2.2 Compaction 1 3.2.3 Gravelshoulders 2 3.2.4 Junction with existing works 2 3.2.5 Tolerance on completed surface . 2 3.2.6 Moisture content and d
5、ensity . . . 2 3.2.7 Acceptance control by statistical analysis 2 . 3.2.8 Screening 2 3.2.9 Designated borrow pit with excessive overburden . 2 3.3 Prestigeprojects 2 3.4 Subeconomicprojects 2 Approved by the PRESIDENT OF THE SOUTH AFRICAN BUREAU OF STANDARDS ISBN 0-626-10591 -9 CODE OF PRACTICE SAB
6、S 0120-2 : Section MFL:1996 SABS 1200 MFL : Base (light pavement structures) NOTES 1 Number the PSMFL clauses in portion 2 of the project specification in the sequence in which the clauses to which they relate appear in SABS 1200 MFL. . . 2 The clause nuniber(s) given at the beginning or after the h
7、eading of a clause islare, unless otherwise stated, the number(s) of the relevant clause(s) of SABS 1200 MFL. 1 Essential project specification clauses Set out suitable clauses in portion 2 of the project specification to provide essential information, as follows: a) (5.4) State the type of base req
8、uired (i.e. natural gravel, crushed stone, stabilized base (state G type) or waterbound macadam), unless the type is at the option of the contractor. b) Where SABS 1200 ME) does not form part of the contract document, take action as set out in 1.2.2 of section MFL of SABS 0120-3. 2 Essential data Th
9、e 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 such as the following in portion 2 of the project specification: a) State the thickness required, and,
10、when relevant, the number of layers. b) (5.6) Schedule the base as waterbound macadam or describe it as such on the drawings, if required. c) Where a degree of compaction or a compaction standard different from that given in 5.4.3.2 of SABS 1200 MFL is required, state the degree of compaction or com
11、paction standard (see 3.2.2 below). d) (3.5) Where the use of sea water is likely to be the most economical and its use is acceptable, say so in a suitable clause. 3 Additional clauses 3.1 General Where it is necessary to amplify or otherwise to vary the terms of SABS 1200 MFL to render them suitabl
12、e for use in projects to be carried out in particular locations or under particular circumstances, include in portion 2 of the project specification clauses dealing with matters other then those covered by clauses 1 and 2. 3.2 Normal projects NOTE -To meet requirements imposed by various norms of ec
13、onomicdevelopment, projects are classified as normal, prestige, subeconomic, and labour-based projects (see the Introduction to SABS 0120-3). 3.2.1 Physical properties of natural gravels (3.3.1) Where necessary (e.g. to avoid the expense of importation), the grading limits and other physical propert
14、ies required may be varied by means of a suitable PS clause or a G5 material may be specified. 3.2.2 Compaction (5.4.3) Where a higher degree of compaction is required, include a clause in the project specification that amends the degree of compaction from 98 % of modified AASHTO maximum density to,
15、 say, 100 % of modified density, or insert a project specification clause that allows for a tendered price for the additional cost of achieving the higher degree of compaction, such as the following: PSMFLl Compaction PSMFL1 .l Degree of compaction (5.4.3.2) The base shall be compacted throughout to
16、 at least either (a) 98 % of modified AASHTO maximum density, or (b) 100 % of modified AASHTO maximum density, as ordered by the engineer. 1) Subbase. SABS 01 20-2 Section MFL:I 996 Base (light pavement structures) PSMFL1.2 Measurement and payment The additional cornpaction (from 98 % to 100 %) of m
17、odified AASHTO maximum density) will be measured extra over base compacted to 98 % of modified AASHTO maximum density, by volume. The unit rate shall cover the cost of the additional compactive effort to achieve the higher degree of compaction where ordered and shall cover the cost of the additional
18、 base material. 3.2.3 Gravel shoulders (5.4.1) 3.2.3.1 Where shoulders are to be constructed and are of the same material as that of the base, insert a suitable clause requiring that they be constructed at the same time as the base. 3.2.3.2 Where the shoulders are of a different material from that o
19、f the base, insert a suitable cause requiring that they be constructed before the base, drawing attention to the need to so programme the operation that clrainage problems do not arise, and placing the responsibility on the contractor to meet the cost of rectifica.tion if drainage problems do arise.
20、 3.2.4 Junctions With existing works (5.7) 3.2.4.1 Where the contract covers the widening of an existing road, the contractor can be expected to evaluate the cost of dealing with the junction between old and new work in terms of 5.7 of SABS 1200 MFL and to include such cost in his rate for the base.
21、 3.2.4.2 Where a large number of intersections with existing roads are involved and where it is not clear at the tender stage whether the junctions will be required at the wide or at the narrow ends of bellmoulhs, schedule a separate item for such junctions, measured by length, and set out a suitabl
22、e clause specifying1 the circunstances under which payment will be made for the item. 3.2.5 Tolerance on completed surface (6.1 “2) In the case of all roads that are provided with kerbs and channels, set out a suitable clause that relates the tolerance specified far the base to the level of the chan
23、nel. 3.2.6 Moisture content and density (6.2) Specify the degree of accuracy required or the permissible deviations that will be accepted if Degreo of Accuracy II is not acceptable. 3.2.7 Acceptance control by statistical analysis (7.1) (See 6.1 of SABS 1200 M*) and 2.3 of section M of SABS 01 20-3.
24、) Where acceptance in accordance with a statistical control plan is required, set out the details in a suitable clause. 3.2.8 Screening Where pedogenic materials are to be used for natural bass, it might be necessary to allow for prescreeming to remove fine or soft material (or both) before processi
25、ng. 3.2.9 Designated borrow pit with excessive overburden (8.3.13) Where the quantity of overburden is excessive or difficult for the contractor to forecast reliably, considttr the economic advantages of scheduling the handling of overburden separately. In such circumstances, set out the requirement
26、s in a suitable clause and schedule an item for dealing with overburden. 3.3 Prestige projects Not applicable to light pavement structures. Where a project includes a heavy pavement structure, such as a main road or a bus route, use SABS 1200 MFH) for such portions. (Until such time as SABS 1200 1-1
27、) is available, specify the quality of the material required in terms of SABS 1200 M) and include suitable project specification clauses to deal with construction, including the processing and control of such material. 3.4 Subeconomic projects The requirements of SABS 1200 MFL are suitable for those roads of subeconomic projeclts that are to be bitumen surfaced but might sek standards that are too high for other roads covered by such projects. 2) Roads (general). 3) Base (heavy pavement structures) (In course of preparation). sabs pta
