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 0120-5 Section MH:1996 Asphalt base and surfgclng First revision Part 5 : Contract administration Section MH Contents Page 1 Startofconstruction 1 1
4、1 General . 1 2 Immediately afler the handing aver of the site . 1 2.1 Approval of bitumen distributor 1 3 Dwingconstruction 1 3.1 Administration 1 3.1.1 Correctionofbase . 1 3.1 2 Feed bins and filler hopper . 1 3.1.3 Hotasphaltstorage 1 3.1.4 Acceptance testing by the engineer 1 3.1.5 Spread rate
5、 for pre-coated chips . 1 3.1.6 Bituminous binder control plant 1 3.1.7 Measurement and payment for mineral filler 1 3.2 Constructionmethods 2 3.2.1 Mixing 2 3.22 RoUersandrolling . 2 3.2.3 Protection of kehs. channels, etc 2 3.2.4 Priming . 2 3.2.5 Transportation of the mixture . 2 3.2.6 Compaction
6、 2 3.2.7 Texturedepth 2 . 4 Quality control and other considerations 2 This section of the code supersedes SABS 0120-5 : Section MH:1981 Approved by the PRESIDENT OF THE SOUTH AFRICAN BUREAU OF STANDARDS CODE OF PRACTICE SABS 0120-5 : Section MH:1996 SABS 1200 MH : Asphalt base and surfacing NOTE -
7、The clause number(s) given in brackets 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 MH. 1 Start of construction 1.1 General For the purposes of this part of the code, contract administration starts with instru
8、ctions to the contractor to commence work as set out in 4.1 of the lntraduction to the code. 2 Immediately after the handing over of the site 2.1 Approval of bitumen distributor TMH 2) sets out requirements for a bitumen distributor. 3 During construction 3.1 Administration 3.1 .l Correction of base
9、 The base (after the prime coat has been applied) should be checked for smoothness and accuracy of grade, elevation and cross-section. The engineer should consider allowing the contractor to rectify, at his own expense, by means of premixed asphalt, any portion of the base that does not comply with
10、the specified requirements. The asphalt used for the correction of the base should be the same mixture as that specified for continuously graded surfacing, and the maximum size of aggregate used should, in each case, be dictated by the thickness required for the correction. 3.1.2 Feed bins and fille
11、r hopper The contractor should carry out regular tests on the grading of aggregate entering the mixing plant. The testing procedure and frequency should be as approved by the engineer. 3.1 -3 Hot asphalt storage Hot asphalt should not be stored for longer than 4 h unless the bins are properly insula
12、ted and fitted with thermocouples that continuously indicate the temperature of the material. 3.1.4 Acceptance testing by the engineer As the cost of asphalt work and of delays in the work can be very high, the engineer should carry out his control testing as speedily as possible and advise the cont
13、ractor promptly of the acceptance or otherwise of the work or portion of the work. 3.1.5 Spread rate for pre-coated chips For a stone that has a relative density of 2,68 g/cm3, the nominal rates of ap lication given in 8.1.7 of SABS 1200 MH are equivalent to 335 m2/m3 for 13,2 mm and 16 mm chips, an
14、d 298 m2/m for 19 mm chips. 3.1.6 Bituminous binder control plant (4.3.1.8 and 5.6.3) Although both the plant and the method of proportioning specified for batch mixing permit the bituminous binder to be proportioned by mass or by volume, proportioning by mass is preferable. 3.1.7 Measurement and pa
15、yment for mineral filler (8.1.6 and 8.4.3) The requirements of 8.1.6 and 8.4.3 place on the contractor the responsibility of determining the quantity of mineral filler required, and of satisfying the engineer that the quantity of mineral filler provided is the correct quantity for the aggregate bein
16、g used. 1) National stanohrd for the spraying performance of binder distributers, published by the NITRR. SABS 0120-5 Section MH:1996 Asphalt base and surfacing First revlsion 3.2 Construction methods 3.2.1 Mixing (5.6.4) In the case of batch mixing, the wet mixing time, based on the Ross count proc
17、edure, should be determined by the contractor and approved by the engineer for each individual plant and for each type of mixture used. However, in no case should the wet mixing time be less than 20 S. The dry mixing time should be at least 10 s but, should mixing be found to be incomplete after 10
18、S, a dry mixing time of up to 15 S might h3 required. 3.2.2 Rollers and rolling A three-wheel roller is more efficient and effective than a tandem roller. Rolling should be carried out from the low side to the high side and should be as slow as possible with no jerking or stoppages for long periods,
19、 on hot asphalt. 3.2.3 Protection d kerbs, channels, etc. (5.1.3) The Cape Town City Council specifies the use of sprayed chemicals for the protection of kerbs, channels, etc., from splashes of bitumen. 3.2.4 Priming Where sharp horizontal curves are encountered, the prime should be applied in half-
20、widths, and on long grades, the prime should be applied with the distributor travelling uphill. 3.2.5 Transportation of the mixture (5.6.5) A thin vegetable oil, soap solution or creosote are suitable release agents. No loads should be sent out so late in the day as to make it impossible to spread a
21、nd compact the) mixture during daylight or under the correct temperature conditions. 3.2.6 Compaction (5.8) After longitudinal joints and edges have been compacted, rolling should start longitudinally at the sides and gradually progress toward the centre of the pavement, except that, on superelevate
22、d curves or where the road has a straight crossfall, rolling should begin on the low side and progress to the high side, each preceding track being uniformly lapped. The rollers should move at a slow but uniform speed (not exceeding 5 kmlh), with the drivc3 roll nearest to the paver. 3.2.7 Texture depth (5.1 0 and 6.3.7.2) The texture depth should be about 750 pm. 4 Quallty control and other conslderatlons Apply the relevant recommendations of SABS IS0 9000) to the construction of asphalt base and surfacing. 2) Quality management systems. sabs pta
