149SECTION 204—STONE FOR MASONRY, RIPRAP , POROUS BACKFILL, AND GABIONS
204.01 Description
These specifications cover aggregate materials used in the construction of masonry items and stone gabions, to protect ground slopes from erosion or wave action and to facilitate drainage, generally behind a backwall or abutment.
204.02 Detail Requirements
a.Stone for rubble or mortar rubble masonry shall be sound, durable, and free from seams, cracks, and other structural defects and shall be minimum Grade C free from rounded, worn, or weathered surfaces.
b.Stone for riprap and bedding shall be sound, durable, and free from seams, cracks, and other structural defects. Riprap stone and bedding exposed to the wave action of water shall be of igneous or metamorphic origin. Riprap bedding shall be crushed stone, minimum Grade B.
c.Porous backfill shall be aggregate size No. 78 or No. 8, a minimum Grade B. Crushed glass meeting the gradation requirements specified in Section 203.02(d) may be directly substituted for size No. 78 and 8 aggregates.
d.Gabion stone shall be durable and free from seams and cracks. Weathered stone shall not be used. Stone shall weigh between 4 and 30 pounds except that approximately 5 percent of the individual stones may weigh less than 4 or more than 30 pounds. At least 50 percent of the stone shall weigh more than 10 pounds. SECTION 205—CRUSHER RUN AGGREGATE
205.01 Description
These specifications cover crushed aggregate used for backfilling and bedding pipe and box culverts, maintaining traffic, and repairing and constructing all-weather private access pavements.
205.02 Materials
Crusher run aggregate shall be crushed from stone, slag, or gravel and shall contain all of the sizes pro - duced when the original aggregate is reduced through a series of crushers to the maximum size specified. It shall be essentially free from deleterious substances in accordance with Section 203.
a.Crushed hydraulic cement concrete will be permitted for use as crusher run aggregate provided it conforms to the physical requirements of Section 203 and shows no adverse chemical reaction. It shall not be used in a subsurface drainage application in combination with perforated pipe or as a base material where geotextile fabric is to be used.205.02 150205.02
b.Crushed gravel shall consist of particles of which at least 90 percent by weight of material retained on the No. 10 sieve shall have at least one face fractured by artificial crushing. Tests to verify accep - tance shall be performed in accordance with VTM-15.
c.Crushed glass will be permitted for use as crusher run aggregate provided it conforms to the physical requirements of Section 203.02(d). Crushed glass having the gradation specified in Section 203.02(d) may be directly substituted for size No. 25 and 26 aggregates in pipe bedding and back - filling applications only.
205.03 Detail Requirements
a.Grading: Grading shall conform to the following requirements when tested in accordance with AASHTO T27: % by Weight of Materials Passing Sieve Size No . 2½ in 2 in 1½ in 1 in ¾ in No. 4 24 Min. 100 95±5 32±18 25 Min. 100 95±5 32±18 26 Min. 100 95±5 38±22
b.Atterberg Limits: The liquid limit shall be not more than 25. The plasticity index shall be not more than 3. Tests to verify acceptance shall be performed in accordance with VTM-7.
c.Soundness: Soundness shall conform to the requirements of Table II-4. Tests to acceptance shall be performed in accordance with AASHTO T103 or T104. The requirement for soundness test for crushed glass is waived due to its preclusion from the applications shown in Table II-4.
d.Abrasion Loss: Abrasion loss shall be not more than 45 percent. Tests to verify acceptance shall be performed in accordance with AASHTO T96.
e.Flat and Elongated Particles: Crusher run aggregate to be used as a temporary riding surface during construction activities or as the final riding surface after construction shall contain not more than 30 percent by mass of aggregate particles retained on and above the 3/8-inch sieve having a maximum to minimum dimensional ratio greater than 5 as determined in accordance with ASTM D4791. SECTION 206—LIGHTWEIGHT AGGREGATE
206.01 Description
These specifications cover lightweight aggregate used in the production of hydraulic cement concrete and asphalt surface treatment.
206.02 Detail Requirements
Lightweight aggregate shall consist of clay, shale, or slate expanded through a sintering or rotary kiln.
Source: Virginia Road and Bridge Specifications, 2020 Edition. Pages 177–177 of 1,065.