HomeMy WebLinkAbout20150079 Ver 1_Other_20150511Section 1043 ,
1 All stone shall meet the approval of the Engineer. While no specific gradation is required,
2 there shall be equal distribution of the various sizes of the stone within the required size
3 range. The size of an individual stone particle will be determined by measuring its long
4 dimension.
5 Stone or broken concrete for rip rap shall meet Table 1042-1 for the class and size
6 distribution.
TABLE 1042-1
ACCEPTANCE CRTI'ERIA FOR RIP RAP AND STONE FOR EROSION CONTROL
Class Re uired Stone Sizes, inches
__ __ Minimum Midrange Maximum
A 2 4 6
- B — ---- 5 8 12
1 i 5 10 17
2 9 14 23
7 No more than 5.0% of the material furnished can be less than the minimum size specified nor
8 no more than 10.0% of the material can exceed the maximum size specified.
9 SECTION 1043
10 AGGREGATE FROM CRUSHED CONCRETE
11 1043-1 GENERAL
12 Aggregate from crushed concrete is a recycled product made by crushing concrete obtained
13 from concrete truck clean out, demolition of existing concrete structures or pavement, or
14 similar sources and transported from a crushing facility. It does not include concrete
15 pavements that are rubblelized, broken or otherwise crushed in place on the roadway.
16 The crushed material must meet all sources approval requirements described in Sections 1005
17 and 1006 with the exception of the sodium sulfate test requirement. Deleterious materials
18 shall not be more than 3%.
19 Sampling and acceptance for the determination of gradaction, LL and PI will be performed as
20 described in the Aggregate QC/QA Program Manual and the Aggregate Sampling Manual.
21 1043-2 AGGREGATE BASE COURSE
22 The material shall meet the ABC gradation. The LL of the material shall be raised 5 points to
23 no more than 35. '
24 1043-3 AGGREGATE SHOULDER BORROW
25 The material shall meet Section 1019.
26 1043-4 CLEAN COARSE AGGREGATE FOR ASPHALT
27 The material shall meet the gradation of a standard size in Table 1005-1. Use of the material
28 shall be approved by the Engineer, and the mix shall meet all requirements.
29 1043-5 CLEAN COARSE AGGREGATE FOR CONCRETE
30 The material shall meet the gradation of a standard size in Table 1005-1. Use of the material
31 is restricted to Class B concrete mixes only. Use of the material shall be approved by the
32 Engineer, and the concrete shal? meet all requirements.
33 SECTION 1044
34 , SUBSURFACE DRAINAGE MATERIALS
35 1044-1 SUBDRAIN FINE AGGREGATE
36 Subdrain fine aggregate shall meet No. 2S or 2MS in Table 1005-2.
10-62 NCDOT 2012 Standard Specifications
1992
� TABLE 3.19-C
GRADED RIPRAP - WEIGHT ANALYSIS
Riprap Weight Requirements for
Class T e Range* (lbs.� Stone Mixture
Class AI
Class I
Class II
Class III
Type I
Type II
25-75
50-150
150-500
500-1,500
1,500-4,000
6,000-20,000
Max. 10% > 75 lbs.
60% > 100 lbs.
50% > 3001bs.
50% > 9001bs.
Av. wt. = 2,000 lbs.
Av. wt. = 8,000 lbs.
* In all classes/types of riprap, a maximum 10% of the stone in
the mixture may weigh less than the lower end of the range.
Source: Adapted from VDOT Road and Bridge S�ecifications
3.19
Filter Fabric Underlinine
A lining of engineering filter fabric (geotextile) shall be placed between the riprap and the
underlying soil surface to prevent soil movement into or through the riprap. Table 3.19-D
notes the minimum physical properties of the filter fabric.
Filter fabric shall not be used on slopes greater than 1 Z:1 as slippage may occur and should
be used in conjunction with a layer of course aggregate (granular filter blanket is described
below) when the riprap to be placed is Class II or larger.
Granular Filter
Although the filter cloth underlining or bedding is the preferred method of installation, a
granular (stone) bedding is a viable option when the following relationship exists:
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�
1992
TABLE 3.19-B
GRADED RIPRAP - DESIGN VALUES
Mean Dis Mean Dso
D� Spherical Spherical
Riprap Weight Diameter Diameter
Class lbs. ft. ft.
Class AI
Class I
Class II
Class III
Type I
Type II
25
50
150
500
1,500
6,000
Source: VDOT Draina�e Manual
0.7 0.9
0.8___.____._ 1.1
�1.3 16�
1.9` 2.2
2.6 2.8 .
4.0 4.5
3.19
The designer, after determining the riprap size that will be stable under the flow conditions,
shall consider that size to be a minimum size and then, based on riprap gradations actually
available in the area, select the size or sizes that equal or exceed the minimum size. The
possibility of damage by children shall be considered in selecting a riprap size, especially if
there is nearby water or a gully in which to toss the stones.
Thickness
The minimum thickness of the riprap layer shall be 2 times the maximum stone diameter,
but not less than 6 inches.
Oualitk of Stone
Stone for riprap shall consist of field stone or rough unhewn quarry stone of approximately
rectangular shape. The stone shall be hard and angular and of such quality that it will not
disintegrate on exposure to water or weathering and it shall be suitable in all respects for
the purpose intended. The specific gravity of the individual stones shall be at least 2.5.
Rubble concrete may be used provided it has a density of at least 150 pounds per cubic foot,
and otherwise meets the requirement of this standard and specification.
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