Section 705 — Rock
705.01Gabion and Revet Mattress Rock. Provide angular stone from a rock quarry or cut that is hard, durable, free of organic and other unsuitable material, and resistant to weathering and water action. Do not use crushed river rock or rock with rounded surfaces. Conform to the following:
(a)Durability index ( coarse ), AASHTO T 210 50 minimum
(b)Density of a filled basket 100 lb/ft3 minimum
(c)Gradation. Provide rock with breadth and thickness at least one- third its length.
(1)Baskets 1 foot or greater in the vertical dimension.
(a)Maximum dimen sion 8 inches
(b)Minimum dimension 4 inches
(2)Baskets less than 1 foot in the vertical dimension.
(a)Maximum dimension 6 inches
(b)Minimum dimension 3 inches
(d)Los Angeles abrasion, AASHTO T 96 50 percent maximum
705.02Rock for Riprap. Provide hard, durable, angular rock that is resistant to weathering and water action, and free of organic and other unsuitable material. Angular rock is characterized by sharp, clean edges at the intersections of relatively flat surfaces. Do not use shale, rock wit h shale seams, or other fissile or fissured rock that may break into smaller pieces in the process of handling and placing. Conform to the following:
(a)Apparent specific gravity, AASHTO T 85 2.40 minimum
(b)Absorption, AASHTO T 85 4.0 percent maximum
(c)Soundness of aggregate using sodium sulfate, AASHTO T 104 (5 cycles) 12 percent loss maximum
(d)Los Angeles abrasion, AASHTO T 96 50 percent maximum
(e)Rock particle intermediate dimension (width) and minimum dimension (thickness) ⅓ longest dimension (length) minimum
(f)Gradation, FLH T 521 Table 705-1 Table 705-1 Gradation Requirements for Riprap(1)
Class Percent of Rock
Equal or Smaller
by Count, DX Range of Intermediate
Dimensions,
inches(2) Range of Rock Mass, pounds(3) 1 100 9 to 15 59 to 270 85 7 to 11 28 to 110 50 5 to 8 10 to 42 15 3 to 6 2 to 18 2 100 15 to 21 270 to 750 85 11 to 15 110 to 270 50 8 to 11 42 to 110 15 6 to 8 10 to 42 3 100 21 to 27 750 to 1600 85 15 to 19 270 to 560 50 11 to 14 110 to 220 15 8 to 10 42 to 81 4 100 27 to 33 1600 to 2900 85 19 to 23 560 to 990 50 14 to 17 220 to 400 15 9 to 12 59 to 140 5 100 33 to 39 2900 to 4850 85 23 to 28 990 to 1800 50 17 to 20 400 to 650 15 11 to 15 110 to 270 6 100 39 to 45 4850 to 7400 85 28 to 32 1800 to 2650 50 20 to 23 650 to 990 15 13 to 17 180 to 400 7 100 45 to 54 7400 to 12,800 85 32 to 38 2650 to 4450 50 23 to 28 990 to 1800 15 15 to 20 270 to 650 8 100 54 to 66 12,800 to 23,400 85 38 to 47 4450 to 8450 50 28 to 35 1800 to 3500 15 19 to 25 560 to 250 9 100 66 to 78 23,400 to 38,600 85 47 to 55 8450 to 13,500 50 35 to 41 3500 to 5600 15 22 to 30 870 to 2200 10 100 78 to 90 38,600 to 59,300 85 55 to 64 13,500 to 21,300 50 41 to 48 5600 to 9000 15 26 to 36 1450 to 3800
(1)Gradation includes spalls and rock fragments to provide a stable, dense mass.
(2)The intermediate dimension is the longest straight -line distance across the rock that is perpendicular to the rock’s longest axis on the rock face with the largest projection plane.
(3)Rock mass is based on a specific gravity of 2.65 and 85 percent of the cubic volume as calculated using the intermediate dimension . 800 705.03 Rock for Masonry Structures. Provide sound, durable rock of the texture and color specified. Provide rock without reeds, rifts, seams, laminations, and minerals that may cause discoloration or deterioration from weathering. Unless otherwise specified, provide rock fragments with the following dimensions:
(a)Minimum thickness 5 inches
(b)Minimum width 12 inches or 1½ times the thickness, whichever is greater
(c)Minimum length 1½ times the width
(d)Rocks with volume ≥1 cubic foot 50 percent minimum When headers are required, provide hea ders with lengths at least the width of bed of the widest adjacent stretcher plus 12 inches.
705.04Rock for Special Rock Embankments. Provide angular rock that is hard, durable, resistant to abrasion and weathering, and that is free of weak cleavages that may cause the rock to disintegrate during handling and placing.
(a)Mechanically -placed embankments. Provide rock conforming to Table 705-2. Table 705-2
Range of Mechanically- Placed Rock
Percent of Rock
Fragments by
Mass Range of In termediate
Dimensions,
inches(1) Range of Rock Mass, pounds(2) 50 > 29 > 2000 50 10 to 29 90 to 2000
(1)The intermediate dimension is the longest straight -line distance across the rock that is perpendicular to the rock’s longest axis on the rock face with the largest projection plane.
(2)Rock mass is based on a specific gravity of 2.65.
(b)Hand- placed embankments. Provide rock conforming to Table 705-3. Table 705-3
Range of Hand- Placed Rock
Percent of Rock
Fragments by
Mass Range of Intermediate
Dimensions,
inches(1) Range of Rock Mass, pounds(2) 75 > 14 > 165 25 10 to 14 90 to 165
(1)The intermediate dimension is the longest straight -line distance across the rock that is perpendicular to the rock’s longest axis on the rock face with the largest projection plane.
(2)Rock mass is based on a specific gravity of 2.65.
705.05Rock for Buttresses.
(a)General. Provide angular rock that is hard, durable, free of organic and other unsuitable material, and resistant to weathering and water action. Conform to the following:
(1)Rock breadth and thickness At least one -third of the rock length
(2)Apparent specific gravity, AASHTO T 85 2.40 minimum
(3)Absorption, AASHTO T 85 4.0 percent maximum
(4)Durability index (coarse), AASHTO T 210 52 minimum
(b)Mechanically -placed buttresses. In addition to Subsection 705.05(a) , provide rock conforming to Table 705-2.
(c)Hand- placed buttresses. In addition to Subsection 705.05(a) , provide rock conforming to Table 705-3.
705.06Rock for Rockeries. Provide hard, angular, and durable rock that consists of a solid mass without open fractures, foliation, or other planes of weakness that are generally cubical, tabular, or rectangular in shape. Do not provide crushed river rock or rock with rounded surfac es. Conform to the following:
(a)Apparent specific gravity, AASHTO T 85 2.50 minimum
(b)Absorption, AASHTO T 85 4.0 percent maximum
(c)Los Angeles abrasion, AASHTO T 96 50 percent maximum
(d)Durability index (coarse), AASHTO T 210 52 minimum
(e)Soundness of aggregate using sodium sulfate, AASHTO T 104 (5 cycles) 12 percent loss maximum
(f)Size and shape
(1)Rock length See plans
(2)Rock breadth and thickness At least one -third of rock length
(3)Rock dimension 18 in minimum
(4)Cap rock mass 200 lb minimum
705.07Rock Mulch. Provide hard, durable native rock that is resistant to weathering and free of excess moisture, muck, frozen lumps, roots, sod, or other deleterious material conforming to the following:
(a)Maximum particle size 6 in
(b)Minimum particle size 2 in 802 (c) Apparent specific gravity, AASHTO T 85 2.40 minimum
(d)Absorption, AASHTO T 85 4.0 percent maximum
(e)Soundness of aggregate using sodium sulfate, AASHTO T 104 (5 cycles) 12 percent loss maximum
(f)Los Angeles abrasion, AASHTO T 96 50 percent maximum
705.08Filter Rock. Provide hard, durable, angular rock that is resistant to weathering and water action and free of organic or other unsuitable material. Angular rock is characterized by sharp, clean edges at the intersections of relatively flat surfaces. Do not use shale, rock with shale seams, or other fissile or fissured rock that may break into smaller pieces in the process of handling and placing. Conform to the following:
(a)Apparent specific gravity, AASHTO T 85 2.40 minimum
(b)Absorption, AASHTO T 85 4.0 percent maximum
(c)Soundness of aggregate using sodium sulfate, AASHTO T 104 (5 cycles) 12 percent loss maximum
(d)Los Angeles abrasion, AASHTO T 96 50 percent maximum
(e)Rock particle intermediate dimension (width) and minimum dimension (thickness) ⅓ longest dimension (length) minimum
(f)Gradation Table 705-4 Table 705-4
Gradation Requirements for Filter Rock
Percent of Rock by
Mass Range of Intermediate
Dimensions, inches(1) Range of Rock Mass, pounds(2) 20 6 to 8 21 to 49 30 5 to 6 12 to 21 40 3 to 5 2.6 to 12 10 2 to 3 0.8 to 2.6
(1)The intermediate dimension is the longest straight -line distance across the rock that is perpendicular to the rock’s longest axis on the rock face with the largest projection plane.
(2)Rock mass is based on a specific gravity of 2.65.
705.09Wall Facing Fill. Provide hard, durable, angular , or fractured rock without organic or other unsuitable material. Do not use shale, rock with shale seams, or other fissile or fissured rock that may break into smaller pieces in the process of handling and placing. Conform to the following:
(a)Gradation. Provide rock with width and thickness at least one- third its length with a 6 -inch maximum dimension. Ensure that 95 percent of wall facing fill particles minimum dimension ex ceeds welded wire facing opening with remaining 5 percent exceeding one -half of the welded wire facing opening.
(b)Soundness of aggregate using sodium sulfate, AASHTO T 104 (5 cycles) 15 percent loss maximum
(c)Los Angeles abrasion, AASHTO T 96 50 percent maximu m
(d)A minimum of 75 percent of individual particles exhibit an angular, rough, or broken surface either naturally occurring or created by crushing, blasting, or other means. The surface is well de fined by sharp natural angles or fractured edges and consist of one half or more of the projected area, when viewed normal to that face.