SANS 10120-5 MG-1996 Code of practice for use with standardized specifications for civil engineering construction and contract documents Part 5 Contract administration Section MG B.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 0120-5 Section MG:1996 Bituminous surface treatment First revision Part 5 : Contract administration Section MG Contents 1 Startofcnstruction 1 1.1 G

4、eneral . 1 2 Immediately after the handing over of the site . 1 2.1 General . 1 2.2 Samples 1 2.3 Curingcoat l . 2.4 Binderforslurryseal 1 2.5 Alternativebinders . 1 3 Duringconstruction 1 3.1 Constructionmethods 1 3.1 . 1 Flat steel-tyred rollers 1 3.1.2 Aggregate for slurry seal l 3.1.3 Protection

5、 of kehs. channels. etc 1 3.1.4 Spraying of prime and bituminous binders 1 3.1.5 Precoatingmethods 2 3.1.6 Applicationofslurryseal 2 3.1.7 Sandseal . 2 3.2 Administration 2 3.2.1 Mixer for slurry seal . 2 3.2.2 Demarcation of work area . 3 3.2.3 Applicationrates 3 3.2.4 Finishedsurface 3 4 Quality c

6、ontrol and other considerations . 3 This section of the code supersedes SABS 0120-5 : Section MG:l981 Approved by the PRESIDENT OF THE SOUTH AFRICAN BUREAU OF STANDARDS CODE OF PRACTICE SABS 0120-5 : Section MG:1996 SABS 1200 MG : Bituminous surface treatment NOTE - The clause number(s) given in bra

7、ckets at the beginning or after the heading of a clause isfare, unless otherwise stated, the number(s) of the relevant clause(s) of SABS 1200 MG. 1 Start of construction 1.1 General For the purposes of this part of the code, contract administration starts with instructions to the contractor to comme

8、nce work as set out in 4.1 of the Introduction to SABS 0120. 2 Immediately after the handing over of the site 2.1 General Give early attention to the matters set out in 2.2 to 2.5 below. 2.2 Samples (7.1) Test samples of materials should be submitted by the contractor timeously. 2.3 Curing coat (5.3

9、) Unless details have been set out in the drawings or elsewhere in the contract, it is necessary for the engineer to advise the contractor of the areas or sections to be cement-stabilized, to enable him to programme his work effectively. 2.4 Binder for slurry seal (5.5.6) The binder used for slurry

10、seal should not be varied, since any variation will affect adversely the appearance of the finished surface. 2.5 Alternative binders If alternative binders have been offered by the contractor in his tender (see Note (b) in section MG of SABS 0120-4), the engineer should make the choice early. 3 Duri

11、ng construction 3.1 Construction methods 3.1 .l Flat steel-tyred rollers (4.4.3) Flat steel-tyred rollers should be heavy enough to embed the aggregate firmly, but not so heavy as to crush more than a small percentage of the aggregate particles. Generally, the mass of a roller has to be reduced if t

12、he aggregate is susceptible to crushing or has a high flakiness index, or if the existing surface is very hard or uneven. Furthermore, the greater the uniformity of the size of the aggregate particles, the smaller is the amount of crushing that occurs. 3.1.2 Aggregate for slurry seal (3.7) Water may

13、 be used to assist in the screening of aggregate for slurry seal and to clean the aggregate of dust and foreign matter. 3.1.3 Protection of kerbs, channels, etc. (5.1.3) The responsibility for ensuring that kerbs, channels, etc., are not sprayed or splashed with binder or slurry or damaged during sp

14、ray or slurry applications rests with the contractor. He has sole discretion as to the method of protection to be used, e.g. sand, mud, plastics sheeting or cement pockets. A thick mud mixed in a cement mixer and painted on kerbs, channels, etc., has been found to be extremely effective. 3.1.4 Spray

15、ing of prime and bituminous binders (5.1.4, 5.1.5, and 5.2) On sharp curves, the prime and bituminous binders should be sprayed in half-widths, to reduce the effect of the difference between the relative speeds of each end of the spraybar and thus to obtain a more even distribution over the full wid

16、th. On gradients, spraying should be carried out with the distributor travelling uphill. SABS 01 20-5 Section MG:1996 Bituminous surface treatment First revision The road surface temperature at sunrise can be used as a guide in determining whether the minimum temperature specified in 5.1.5 of SABS 1

17、200 MG is likely to be exceeded during the day. For example, the road surface temperature at sunrise should exceed the applicable value listed below. Binder grade Road surface temperature at sunrise, C min. RTH 451508 RTH 501558 RTL 451508 RTL 501558 1501200 (penetration grade) 16 3.1 -5 Pre-coating

18、 methods (5.4.7) 3.1 S.1 Pre-coating of aggregate for immediate use The pre-coating fluid should be a mixture of equal volumes of a tar-based pre-coating fluid, to which should be added 0,5 % (by volume) of an approved wetting agent. The aggregate should be placed in the hopper of the pre-coating ma

19、chine and sprayed with water. All the free water should be allowed to drain off. The stone shoilld then be pre- coated with a pre-coating fluid at the specified rate. 3.1 S.2 Pre-coating of aggregate for stockpiling Except that the pre-coating fluid should consist of 40 % of grade 1501200 penetratio

20、n bitumen plus 5 O/O by volume (of the mixture) of wetting agent (or such other mixture as is required in terms of the schedule or ordered), aggregate for stockpiling should be treated as specified in 3.1 5.1. Stockpiles of pre-coated aggregate should be kept as free from dust as possible. 3.1.6 App

21、lication of slurry seal (5.5.8) As the first layer of slurry dries out, it shrinks down between the stone chips and is pressed further down by the wheels of traffic, thus making room for the second layer. The progress of curing depends on the weather corditions and can be judged by the amount of shr

22、inkage and the hardness of the material. 3.1.7 Sand seal (5.7.2) 3.1.7.1 Surface preparation Although satisfactory results can be obtained when prime is omitted, the use of a prime is nevertheless recommended. 3.1.7.2 Temporary opening to traffic Opening of the primed surface to traffic for 6 weeks

23、prior to sand sealing could result in unnecessary damage to the base. The road need not be opened to traffic at all after priming. 3.1.7.3 Brooming back The brooming-back process should be done with a rotary broom and might have to be continued for as long as 2 months before the surface reaches an a

24、cceptable condition. 3.2 Admlnistratiort 3.2.1 Mixer for sllrry seal (4.6) Provision has been made in 4.6 of SABS 1200 MG for continuous mixers but this type of mixer should be used on major works only, since it is difficult to ensure consistency in continuous blending and mixing of the constituents

25、 of the slurry. Controls to ensure such consistency are warranted only if the programmed output is large and will be spread over a considerable period of time. SABS 0120-5 Section MG:1996 Bituminous surface treatment First revision 3.2.2 Demarcation of work area (5.1 -2) It is the contractors respon

26、sibility to demarcate the area of a road to be sprayed and to ensure that a straight-line intersection is achieved at joints with existing roads. In particular, he should mark the centre-line of the road as an aid to ensuring that the longitudinal joint is parallel with the centre-line. Twine, hessi

27、an, or wire may, at the discretion of the contractor, be used as guide lines. 3.2.3 Application rates (5.1.7) Where a prime has been omitted or is observed to have penetrated further than expected, the bitumen application rate should be increased by up to 0,15 d/m2. Because of the more effective wet

28、ting action of emulsions, the application rates when emulsions are used may be reduced. (See TRH 3).) 3.2.4 Finished surface (6.2) The distance between the surface and the straightedge should be measured with a flat wedge so that any roughness in the texture of the surfacing does not interfere with the measurement. 4 Quality control and other considerations Apply the relevant recommendations of SABS IS0 9000) to bituminous surface treatment construction. 1 ) Bituminous surface treatments for newly constructed rural roads, published by the NITRR. 2) Quality management systems. 3 sabs pta