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 0120-3 Section MG:1996 Bituminous surface treatment First revision Part 3 : Guidance for design Section MG Contents Page 1 Pre-tenderconsiderations
4、l 1.1 Investigations . 1 1.1.1 Fogspray 1 1.1.2 Precoating . 1 . 1.1.3 Singlesurfacetreatment l 1.2 Administration . 1 1.2.1 Binder for first or second coats 1 1.2.2 Application rates stated in terms of net quantity of binder . 1 1.2.3 Heating of bituminous binders . 1 1.2.4 Filler for slurry seal .
5、 1 1.2.5 Tenders . 1 1.3 Documentation 2 . 1.3.1 Bitumen preferred to tar 2 1 . 3.2 Binder for manufacture of emulsions 2 1.3.3 Schedule 2 2 Designrequirements 2 2.1 Technical 2 2.2 Aggregate for slurry seal . 2 3 Applicability of other codes . 2 4 Testprocedures . 2 . 4.1 General 2 4.2 Calculation
6、of volume of fine aggregate corrected for bulking . 2 5 Quality control and other considerations 3 This section of the code supersedes SABS 0120-3 : Section MG:1981 Approved by the PRESIDENT OF THE SOUTH AFRICAN BUREAU OF STANDARDS CODE OF PRACTICE SABS 01 20-3 : Section MG:1996 SABS 1200 M : Bitumi
7、nous surface treatment NOTE - The clause number(s) given in brackets at the beginning or after the heading of a clause Mare, unless otherwise stated, the number(s) of the relevant clause(s) of SABS 1200 MG. 1 Pre-tender considerations 1 .l Investigations 1 .l .l Fog spray (5.4.6) Determine whether f
8、og spray will be required over the surface, to prevent or reduce whip-off. 1 .l .2 Pre-coating (5.4.7) Where hydrophilic or other aggregates that might cause difficulties are the most readily and economically available, schedule pre-coating of the second application of aggregate. 1 .l .3 Single surf
9、ace treatment (5.6) Although single surface treatment costs less than any other type of treatment, use this treatment only where good material and construction techniques are available and traffic density does not exceed 200 vehicles per lane per day. In particular, a better quality of stone is requ
10、ired for single surface treatment than for multiple surface treatments. 1.2 Administration 1.2.1 Binder for first or second coats (3.3) Although material of grade 801100 is included, it is not normally used in surface treatment because of difficulties associated with binderlaggregate adhesion. Restr
11、ict the use of this material to very hot conditions. 1.2.2 Application rates stated in terms of net quantity of binder (5.1.7 and 8.1) Where the application rate is specified in net quantity of binder per square metre, take into account the percentage of bitumen in the particular binder (e.g. genera
12、lly 60 by volume in bituminous emulsions and 80 % in MC-3 000 cutback bitumen). 1.2.3 Heating of bituminous binders (5.1.6) 1.2.3.1 The temperatures at which bituminous binders are mixed and sprayed are of the utmost importance. The graphs given in appendix C of SABS 308) show the range of kinematic
13、 viscosities of commonly used types of bituminous binders. (See also 1.2.3.3.) 1.2.3.2 Neither the contractors nor the engineers representative in the field can be expected to have at his finger tips information on the kinematic viscosity of the various binders. The contractor should therefore obtai
14、n from the supplier the recommended handling temperatures, and adhere to the recommendations. However, where the recommended temperatures fall outside the limits specified in 5.1.6 of SABS 1200 MG, the contractor should advise the engineer of the conflict and ask for instructions. 1.2.3.3 The sprayi
15、ng temperatures given in table 3 of SABS 1200 MG are based on a viscosity range of 40 mm2/s to 100 mm2/s. 1.2.3.4 PVC-modified tars in the RTL grades can be stored at a temperature of 11 0 C for 4 d without degradation of the polymer although at this temperature, some increase in EVT can be expected
16、 Degradation of the PVC might occur if the road tar binder is stored for more than 48 h at a temperature above 120 C. Under no circumstances may a PVC tar be stored at a temperature above 140 C. 1.2.4 Filler for slurry seal (5.5.6 and 3.9) Do not vary the type of filler required. Use as a filler ei
17、ther portland cement or portland blastfurnace cement consistently, since alternating of the materials causes patches of different colours in the finished surface. 1.2.5 Tenders Ensure that action has been taken on the matters set out in 3.1.2 (a) and (b) of the Introduction to SABS 0120-1 before the
18、 start of construction. 1) Cutback bitumen. SABS (111 20-3 Section MG:1996 Bituminous surface treatment First revision 1.3 Documcantatiorr 1.3.1 Bitumen preferred to tar Bitumen is generally preferred to tar on account of the delays that occur when tar is used in seal work. However, it has been clai
19、med that the life of sand seals bound with bitumen is much shorter than that of those bound with tar, that some of the best sand seals have been dhoss produced with tars, and that RTH 15/20 road tars have) been found to give excellent service. Generally, coal tars originating in the Transvaal have a
20、 high volatiles content and a long curing period L required, whille those originating in Dundee, Natal, have a lower volatiles content and the curing period might be shorter by comparison. 1.3.2 Binder for manufacture of emulsions Refer to TRH 32) for guidance on the grade of penetration bitumen for
21、 emulsions suitable for the climatic corlditions at the site. 1 3.3 Schedule (0.4) See Note (b) in section MG of AB 0120-4. 2 Design requirements 2.1 Technical Consult whichever of TRH 13), IRH 32) or TRH 74) deals with the type of construction that is most suitable for the project. 2.2 Aggregate fo
22、r slurry seal (3.7) A naturally occurring sand may be considered for use in slurry seal in areas where crusher dust is not readily available but it could give rise to adhesion problems and reduced durability. Investigation into the availability of material in the vicinity of the site is warranted. 3
23、 Applicability oif other codes There are no SABS codes of practice that are applicable to the design of bituminous surface treatment, but the recommendations of the relevant TRH publications should be taken into account. 4 Test procedures 4.1 General Except where otherwise specified, the test proced
24、ures recommended in TMH 15) are applicable. 4.2 Calculation of volume of fine aggregate corrected for bulking (5.5.9) When determining rates of application of slurry, obtain the corrected volume of fine aggregate by the following method: a) Carefuily measure the volume of a truck hopper filled with
25、fine aggregate (say, A m3). b) Obtain a representative sample of the aggregate. Pour 1 000 mQ of the sample into a plastics measuring cylinder. Drop the cylinder upright ten times through a height of 50 mm onto a wooden table, and then read the volume of aggregate in the cylinder (say, B m). c) Satu
26、rate the mateial in the cylinder with water and add water until the water level is 50 mm above the aggregate. Shake the mixture well and then stand the cylinder on a horizontal surface until the liquid above the aggregate clears sufficiently to enable the volume of the saturated aggregate to be read
27、 (say, C m). - 2) Bituminous surface treatment for newly constructed rural roads, published by the NITRR. 3) Guide on prime coats, tack coats and temporary surfacing for the protection of bases, published by the NITRR. 4) The use of bituminofs emulsions in the construction and maintenance of roads,
28、published by the NITRR. 5) Standard methods or? teting road construction materials, published by the NITRR. SABS 01 20-3 Section MG:1996 Bituminous surface treatment First revision d) Calculate the saturated volume of the aggregate in the hopper of the truck from the following formula: where V is th
29、e true volume (saturated) carried by the truck hopper, in metres A is the measured volume of the truck hopper, in metres cubed; B is the volume of aggregate in the cylinder, in millimetres cubed; and cubed; C is the volume of the saturated aggregate in the cylinder, in millimetres cubed. 5 Quality control and other considerations Apply the relevant recommendations of SABS IS0 9000) to the design of bituminous surface treatment. 6) Quality management systems. 3 sabs pia
