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. SAW 01 20-5 Section MFL:l996 Base (light pavement structures) Part 5 : Contract administration Section MFL Contents Startofconstruction 1.1 General . . I
4、mmediately after the handing over of the site 2.1 Sourcesofmaterialsupply . Duringconstruction . 3.1 Methods of construction . 3.1 . 1 Non-plastic gravel 3.1.2 Maximumsize 3.1.3 Additionofbinder . . 3.1.4 Conyaction against kerbs 3.1.5 Single-size crushed stone base (waterbound macadam base) 3.2 Adm
5、inistration . 3.2.1 Problems with aggregates and gravel 3.2.2 AggregatepH . . 3.2.3 AggregatePI 3.2.4 Protection and maintenance Qualitycontrol Approved by the PRESIDENT OF THE SOUTH AFRICAN BUREAU OF STANDARDS ISBN 0-626-10594-3 Page 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 CODE OF PRACTICE SABS 0120-5 :
6、Section MFL:1996 SABS 1200 MFL : Base (light pavement structures) 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 MFL. 1 Start of construction 1.1 General For the purposes of this
7、 part of the code, contract administration starts with instructions to the contractor to commence work as set out in 4.1 of the Introduction. 2 Immediately after the handing over of the site 2.1 Sources of material supply The recommendations given in 2.1 of section ME of SABS 0120-5) are applicable
8、to this section. 3 During construction 3.1 Methods of construction 3.1 .l Non-plastic gravel (5.4.4) Coarse gravel that contains non-plastic or slightly plastic soil fines and that is used in the construction of a natural gravel base will usually require slushing and rolling in addition to the compa
9、ction specified, to enable a firm, well-knit surface to be obtained. In such a case, after being processed and compacted as specified in 5.4.3 of SABS 1200 MFL, the base should be well watered over short sections at a time and slushed and rolled with compactors or heavy flat wheel rollers (or both)
10、of mass at least 12 t. Watering and rolling should continue over a section until all excess fines have been brought to the surface of the layer. Such excess fines should be uniformly distributed over the surface of the layer by means of stiff brooms, and watering, rolling and brooming should continu
11、e until all areas deficient in fines have been suitably corrected. Finally, all excess fines should be removed from the surface of the layer. 3.1.2 Maximum size In order to ensure optimum workability of the material, the maximum size of stones should, if possible, not exceed one- third of the thickn
12、ess of the layer. 3.1.3 Addition of binder (5.4.1) Where a binder material is to be added to the base material, between 30 % and 50 %, as directed, of the required amount of gravel should be dumped onto the road and spread over its full width. The binder material should then be dumped on top of the
13、gravel, spread, and intimately mixed with the gravel until a uniform mixture is obtained. The remainder of the gravel should then be brought onto the road and mixed with the material containing the binder, until a uniform mixture is obtained. Water should not be added until the binder is fully mixed
14、 with the gravel. 3.1.4 Compaction against kerbs The contractor should pay special attention to the placing and compaction of base material against kerbs and channels, to ensure that the kerb or channel is not damaged by the rollers or compactors, that the required compaction is achieved right up to
15、 the edge of the kerb or channel and that the required levels are obtained. 3.1 .S Single-size crushed stone base (waterbound macadam base) The coarse aggregate is first compacted until the density is deemed to be satisfactory (i.e. when there is virtualty no movement or only a slight amount of move
16、ment in the layer under a 12 t flat steel wheel roller). While rolling continues, the interstices are filled, by brooming and watering, with fine aggregate or natural filler that conforms to a specified grading. 3.2 Administration 3.2.1 Problems with aggregates and gravel Where the contractor has be
17、en allowed to select the source of the base material, it would be reasonable to assume that his tendered price covers the cost of dealing with the problems outlined in 3.1.1 and 3.2.3. Under all other circumstances, he would be entitled to claim extra payment (unless the project specification had gi
18、ven him adequate warning), but should obtain the engineers authority before proceeding on the lines set out in 3.1 .l and 3.2.3. SABS 01 20-5 Section MFL:1996 Base (light pavement structures) 3.2.2 Aggregate pH Crusher run that has a pH value of less than 6 (material that is yellow is particularly s
19、uspect in this regard) should be checked for soluble sulfate content prior to delivery. Hydrated lime may be added under controlled conditions, preferably during crushing and screening, to bring the pH value to not less than 10,O immediately after treatment. In certain cases and only with the prior
20、consent of the engineer, neutralizing additives may be incorporated during construction of the base. 3.2.3 Aggregate PI Fines, if required for correcting areas deficient in fines, should have been approved by the engineer before use and should all pass a 4,75 mm screen. The PI of these fines should
21、not exceed 4 and the material should be free from shales, micaceous arrd organic materials, and other deleterious matter. Where the PI of available fine aggregate exceeds 6, the PI may be reduced by the admixture of aboit 3 % (by mass) of hydrated lime to achieve a residual PI of not more than 4 bef
22、ore the fine aggregate is added to the mixture. 3.2.4 Protection and maintenance (5.8) The engineer should appreciate that he accepts responsibility for, and will pay for, any damage that is done to the surface, if he authorizes the use of an unprimed base by vehicular traffic. 4 Quality control The relevant recommendations of SABS IS0 9000) should be applied to the construction of a base. 2) Quality management systems. sabs pta
