7-27 Sectio N 706 – Ston E for Masonry , Riprap , and Othe R Purposes
706.0 1 STON E FOR MASONRY . Stone for masonry shall be quarry stone, field stone, or rock fragments approximately rectangular in shape and of a hard, sound, and durable quality acceptable to the Engineer. The stone shall be free from structural defects or imperfections that would tend to compromise its resistance to the weather. At least 80% of the individual stones in a unit shall have a thickness of not less than 8 inches and a width of not less than 150% of the thickness. The minimum size of the other stones in the unit shall have a thickness of not less than 4 inc hes and a width of not less than 150% of the thickness. 706.0 2 STON E FOR MASONR Y FACING . Stone for masonry facing shall be irregularly shaped or roughly rectangular quarried granite, marble, or another quarried stone approved by the Engineer . Stone for capping shall conform to the dimensions shown on the Plans unless changes are ordered in writing by the Engineer. The stone shall be of approved quality, tough, sound, and durable, resistant to weathering action, unifor m in color, free from seams, cracks, laminations, pyrite inclusions, and minerals or other structural defects which, by weathering, would cause discoloration or deterioration , and shall be thoroughly cleaned of any iron or rust particles. Stone shall be of such character that it can be wrought to such lines and surfaces, whether curved or plane, as required. Any stone having defects that have been repaired with cement or other materials will be rejected. The stone shall be kept free from dirt, oil, and any other detrimental material that may prevent the proper adhesion of the mortar or detract from the appearance of the exposed surfaces. The front face of the facial stone, including capstones when required, shall be smooth, quarry -split, free from drill hole s in the exposed face, with no projections or depressions greater than 1 inch measured from the vertical plane of the face of the stone. The capstone shall have a top surface sawed to an approximately true plane. The front and back arris lines of the capst ones shall be pitched straight and true. 706.0 3 STON E FOR RIPRAP . Stone for riprap shall be approved, rough, unhewn quarry stone, as nearly rectangular in section as practical. The stones shall be hard, sound, and resistant to the action of water and weat hering. They shall be of a rock type other than serpentine rock containing the fibrous variety chrysotile (asbestos) and suitable in every respect for the purpose intended.
a.Riprap, Heavy Type . The individual stones shall have a depth equal to the thickness of the course of riprap. At least 75% of the volume of the riprap shall consist of stones that have a minimum volume of 16 cubic feet.
b.Riprap, Light Type . The individual stones shall have a depth equal to the thickness of the course of riprap and sha ll have a minimum volume of 1/2 cubic foot. 7-28706.0 4 STONE FILL. Stone for stone fill shall be approved, hard, blasted, angular rock other than serpentine rock containing the fibrous variety chrysotile (asbestos). The least dimension of the stone shall be greater than 33% of the longest dimension. The stone fill shall be reasonably well graded from the smallest to the maximum size stone specified to form a compact mass when in -place.
a.Stone Fill, Type I . The longest dimension of the stone shall vary from 1 inch to 12 inches, and at least 50% of the volume of the stone in -place shall have a minimum dimension of 4 inches.
b.Stone Fill, Type II . The longest dimension of the stone shall vary from 2 inches to 36 inches, and at least 50% of the volume of the stone in -place shall have a minimum dimension of 12 inches.
c.Stone Fill , Type III . The longest dimension of the stone shall vary from 3 inches to 48 inches, and at least 50% of the volume of the stone in-place shall have a minimum dimension of 16 inches.
d.Stone Fill , Type IV . The longest dimension of the stone shall vary from 3 inches to 60 inches, and at least 50% of the volume of the stone in -place shall have a minimum dimension of 20 inches. 706.0 5 ENVIRONMENTA L STONE FILL . Environmental stone ( E-stone ) fill shall be hard, blasted, angular rock other than serpentine rock containing the fibrous variety chrysotile (asbestos). E -stone fill material of the type specified shall be defined as follows:
a.E-Stone Fill, Type I . The longest dimension of the stone shall be at least 18 inches, and at least 50% of the volume of the stone in place shall have a least dimension of 12 inches, and at least 25% of the particles shall have a maximum dimension of 2 i nches and be well graded material.
b.E-Stone Fill, Type II . The longest dimension of the stone shall be at least 24 inches, and at least 50% of the volume of the stone in place shall have a least dimension of 18 inches, and at least 25% of the particles shall have a maximum dimension of 2 inches and be well graded material.
c.E-Stone Fill, Type III . The longest dimension of the stone shall be at least 36 inches, and at least 50% of the volume of the stone in place shall have a least dimension of 24 inches, and at least 25% of the particles shall have a maximum dimension of 2 inches and be well graded material.
d.E-Stone Fill, Type IV . The longest dimension of the stone shall be at least 48 inches, and at least 50% of the volume of the stone i n place shall have a least dimension of 36 inches, and at least 25% of the particles shall have a maximum dimension of 2 inches and be well graded material.
7-29 Section 707 – Joint Materials
707.01 MORTAR . Mortar shall be a hydraulic -cement grout meeting the following requirements:
a.General Requirements . Mortar shall be composed of cement in accordance with Subsection 701.02 , sand in accordance with Subsection 704.01 or Subsection 704.13 , and water in accordance with Subsection 745.01 , unless otherwise specified. Chemical admixtures shall be in accordance with Subsection 725.02 and mineral admixtures shall be in accordance with Subsection 725.03 for the respective admixture used, as required. Masonry cement shall be in accordance with ASTM C91 for the type specified. Hydrated lime shall be in accordance with ASTM C207 . Contractor blended mortars shall be proportioned on site with sufficient water to form a stiff plastic composition. Packaged pre -blended mortars shall be prepared and installed in accordance with the manufacturer’s recommendations. Mortar shall not be re -tempered after it has begun to set.
b.Mortar, Type I . Type I mortar shall be composed of 1 part cement, 2 parts sand, and sufficient water to form a plastic composition.
c.Mortar, Type II . Type II mortar shall meet one of the following requirements:
1.A packaged pre -blended dry mortar in accordance with ASTM C1714 , Type S; or
2.A Contractor blended mortar composed of 1 part cement, 2 -1/2 parts sand, and 1/2 part hydrated lime; or
3.A Contracto r blended mortar composed of 1 part Type S masonry cement and 2 -1/2 parts sand.
d.Mortar, Type III . Type III mortar is generally used as a grout to fill around slope stabilization nails. It may also be used for rock slope stabilization rock dowels, rock anchors, shear keys and rock nails. It shall be a neat material meeting the following requirements:
1.Compressive Strength . Type III mortar shall have a minimum compressive strength of 1,500 psi at 3 days and a minimum compressive strength of 3,500 psi a t 28 days as determined in accordance with AASHTO T 106 .
Source: Vermont Standard Specifications for Construction, 2024 Edition. Pages 1179–1180 of 1,380.