Difference between revisions of "Reservoir aggregate"

From LID SWM Planning and Design Guide
Jump to: navigation, search
m
m
Line 1: Line 1:
 
<poem>
 
<poem>
 
For advice on decorative surface aggregates see [[Stone]]
 
For advice on decorative surface aggregates see [[Stone]]
Gravel for underdrains and underground infiltration structures should be 20 - 50 mm, uniformly-graded, clean (maximum wash loss of 0.5%), crushed angular stone that has a void ratio of 0.4 (40%)<ref>Porosity of Structural Backfill, Tech Sheet #1, Stormtech, Nov 2012, http://www.stormtech.com/download_files/pdf/techsheet1.pdf accessed 16 October 2017 </ref>.
+
 
 +
Gravel used for underdrains and underground infiltration structures should be 20 - 50 mm, uniformly-graded, clean (maximum wash loss of 0.5%), crushed angular stone that has a void ratio of 0.4 (40%)<ref>Porosity of Structural Backfill, Tech Sheet #1, Stormtech, Nov 2012, http://www.stormtech.com/download_files/pdf/techsheet1.pdf accessed 16 October 2017 </ref>.
 +
 
 
The uniform grading and the angularity are important to maintain pore throats and clear voids between particles. (i.e. achieve the void ratio).  
 
The uniform grading and the angularity are important to maintain pore throats and clear voids between particles. (i.e. achieve the void ratio).  
The clean wash is to prevent rapid accumulation of fines in the base of the reservoir.   
+
The clean wash to prevent rapid accumulation of fines from the aggregate particles in the base of the reservoir.   
  
 
Gravel with structural requirements should also meet the following criteria:
 
Gravel with structural requirements should also meet the following criteria:

Revision as of 21:57, 22 November 2017

For advice on decorative surface aggregatesA broad category of particulate material used in construction, including sand, gravel, crushed stone, slag, recycled concrete and geosynthetic aggregates, and available in various particulate size gradations. see Stone

Gravel used for underdrains and underground infiltration structures should be 20 - 50 mm, uniformly-graded, clean (maximum wash loss of 0.5%), crushed angular stone that has a void ratioThe void ratio (e) of a mixture is the ratio of the volume of void-space to the volume of solids. It is closely related to the concept of porosity (n) where porosity is the ratio of the volume of void-space to the total or bulk volume of the mixture. e = Volume of voids/Volume of solids = n/(1-n) of 0.4 (40%)[1].

The uniform grading and the angularity are important to maintain pore throats and clear voids between particles. (i.e. achieve the void ratioThe void ratio (e) of a mixture is the ratio of the volume of void-space to the volume of solids. It is closely related to the concept of porosity (n) where porosity is the ratio of the volume of void-space to the total or bulk volume of the mixture. e = Volume of voids/Volume of solids = n/(1-n)).
The clean wash to prevent rapid accumulation of finesSoil particles with a diameter less than 0.050 mm. from the aggregateA broad category of particulate material used in construction, including sand, gravel, crushed stone, slag, recycled concrete and geosynthetic aggregates, and available in various particulate size gradations. particles in the base of the reservoir.

Gravel with structural requirements should also meet the following criteria:

  • Minimum durability index of 35
  • Maximum abrasion of 10% for 100 revolutions and maximum of 50% for 500 revolutions

  1. Porosity of Structural Backfill, Tech Sheet #1, Stormtech, Nov 2012, http://www.stormtech.com/download_files/pdf/techsheet1.pdf accessed 16 October 2017