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南非土木工程施工标准 MF :基层 英文原文节选 20100079 1-35 |
PIANT
4 . I GENEI:AL. The requirements of Subclause 4. 1 of SABS 1200 I) shall apply.
4.2 COMPACTION PLANT. The requirements of Subclause 4.2 of SABS 1200 D shall apply.
4.3 TRANSPORT. 'rile requirements of Suhclause 4.3 of St\W 1200 D shall apply.
5. CONSTRUCTION
5. I PRECAUTIONS. The requirements of Subclause 5.1 of SABS 1200 D slinll apply.
5.2 EXCAVATION
5.2.1
5.7.2 Horrow P i t s . Where hase mnterinl is excavated from borrow p i t s by the Contractor, the appropriate
5.2.3 Overburden. The requirements of Subclause 5.2.3 of SAUS 1200 ME shall apply.
5.3 PROCESSING. The relevant requirements of Subclause 5.3 of SABS 1200 HI3 shall apply.
5.4 PLACING AND COMPACTION OF A RASE OTllER THAN A WA'i'ERUOUNU MACADAM BASE
5.4. I
W.
of Subclause 5.2.2 of SAIIS 1200 1IM shall apply.
provisions of Subclause 5.2.2.2 of SABS 1200 1) shall apply.
Glliere base material is obtained from a designated excavation on S i t e , the appropriate provisions
Placing.
layer on which the base is to be constructed complies w i t h the requirements of the specification
covering that layer.
Where a nominal thickness exceeding 150 mni has been specified. the base shall be constructed i n
approximately equal layers of thickness not exceeding 150 mm each.
a) Where the base is to be constructed of gravel, the gravel shall be dumped on the road and then
spread over the f u l l width of the layer shown on the drawings and to such depth that a f t e r compaction
the thickness of the layer complies with the specified requirements and the surface of the layer is
true to elevation, grade, and cross-section.
b) Oversize material i n gravel shall be
I ) broken down on the road; or
2 ) bladed off the road during placing and disposed of; or
3) if so directed, so crushed and screened that, when f i n a l l y placed, it complies with the applicable
grading requirements of 3.3. I .
'The material shall be spread, prepared, watered,and mixed as specified in Subclauses 5.4.2 and 5.4.3 of
SABS 1200 ME.
c) Where the addition of a natural binder material is necessary to improve the grading or reduce the PI
of a hase gravel, the Engineer may d i r e c t that a suitable binder he added to and mixed with the gravel
to form a homogeneous material.
a) Idhere the base is to be constructed of graded crushed stone or graded crushed stone with f i n e s , the
material shall he spread out to a flat-surfaced layer over the f u l l width shown on the drawings and to
such s depth that a f t e r compaction the thickness or the layer complies w i t h the specified requirements.
Any fine aggregate to be added shall be spread evenly on top.
watered, and mixed as specified in Subclauses 5.4.2 and 5.4.3 of SAHS 1200 MI!.
b) Any excess crushed stone shall not be spread over the shoulders or side f i l l , but shall be loaded
and removed from the road.
unless it has been rescreened, tested, and approved for use.
Compaction shall be done at the optimum moisture content for the type of compaction equipment used and
as specified in Subclause 5.4.4.1 of SABS 12UO ME.
The base shall he compacted throughout to at l e a s t the following density:
a) In the case of natural gravels, graded crushed stone, and graded crushed stone with fines: 98 % of
modified AiSHTO maximrim density;
b) in the case of stabilized gravels: 97 % of modified AASHTO maximuni density.
Before construction of the base is commenced the Contractor shall ensure t h a t t h e underlying
5.4.2 Gravel
5.4.3 Graded Crushed Stone and Graded Crushed Stone with Pines
Then the material shall be prepared,
It shall not be used again, e i t h e r alone or mixed with approved material,
5.4.4 Compact ion
5.4.4.1
5.4.4.2
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5.4.5 Surface Preparation
5.4.5.1 After cotnoaction of a base that has not been s t a b i l i z e d , the surface shall be slushed bv . sn.rav.ine- it
with water and rolling t i l l a l l excess fines have been brought to the surface and a firm well knit
surface has been obtained.
fines. A l l excess fines shall be swept off the surface and the hase allowed to dry out.
5.4.5.2 After compaction of stabilized base, areas deficient in fines shall be corrected by brooming in an
approved mixtiire of fines and s t a b i l i z i n g agent.
5.5.6 of SAHS 1200 ME for 4 d and primed a f t e r the applicable of the following periods:
a) Base stabilized w i t h unslaked l i m e : a f t e r a t l e a s t 7 d ;
b) base stabilized w i t h cement, slaked lime, or slag mixtures: a f t e r 24 h and preferably within 7 d.
5.5 STABII.IZATION. When required in terms of the drawings or the project specification or when ordered,
Any areas deficient in f i n e s s h a l l he corrected by brooming in approved
The layer shall be kept w e t as specified in Subclause
the base shall he stabilized as specified in Subclause 5.5 of SAUS 1200 ME. The stabilized base shall
be compacted throughout to the density specified in 5.4.4.2.原件下载：  |
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