OPSS aggregates

Of the standard granular materials in the standard OPSS.PROV 1010 only Granular O is recommended as a substitute for clear stone in LID construction. 
Examples of BMPs with underground reservoirs include Underdrains, infiltration trenches, permeable pavements, infiltration chambers, exfiltration trenches. 
All other mixes must be avoided for free drainage or storage as they are permitted to contain a higher enough proportion of fines to reduce permeability below 50 mm/hr. 
===Justification===
 Grain size analysis, percent passingOPSS. (2013). Material Specification for Aggregates - Base, Subbase, Select Subgrade, and Backfill Material. Retrieved from https://www.toronto.ca/wp-content/uploads/2017/11/91ba-ecs-specs-roadspecs-TS_1010_Sep2017.pdf OPSS. (2020). Construction Specification for Open Grades Drainage Layer. OPSS.PROV 320. Retrieved from: https://www.toronto.ca/wp-content/uploads/2017/11/91ba-ecs-specs-roadspecs-TS_1010_Sep2017.pdf
Sieve size (mm) 	A 	A 	B type I	B type I	B type II	B type II	B type III	B type III	M 	M 	O 	O 	(SSM)
Select Subgrade Materials	(SSM)
Select Subgrade Materials	(OGDL)
Open Graded Drainage Layer	(OGDL)
Open Graded Drainage Layer
Sieve size (mm) 	High	Low 	High 	Low 	High 	Low 	High 	Low 	High	Low 	High 	Low 	High	Low 	High 	Low
150 	 	 	100 	100 	 	 	100 	100 	 	 	 	 	100 	100 	 	
106 	 	 	 	 	100 	100 	 	 	 	 	 	 	 	 	 	
37.5 	 	 	 	 	 	 	 	 	 	 	100 	100 	 	 	100 	100
26.5 	100 	100 	50 	100 	50 	100 	50 	100 	 	 	95 	100 	50 	100 	100 	95
19 	85 	100 	 	 	 	 	 	 	100 	100 	80 	95 	 	 	100 	90
13.2 	65 	90 	 	 	 	 	 	 	75 	95 	60 	80 	 	 	86 	40
9.5 	50 	73 	 	 	 	 	32 	100 	55 	80 	50 	70 	 	 	55 	20
4.75 	35 	55 	20 	100 	20 	55 	20 	90 	35 	55 	20 	45 	20 	100 	10 	0
1.18 	15 	40 	10 	100 	10 	40 	10 	60 	15 	40 	0 	15 	10 	100 	 	
0.3 	5 	22 	2 	65 	5 	22 	2 	35 	5 	22 	 	 	5 	95 	 	
0.15 	 	15 	 	 	 	 	 	 	 	 	 	 	2 	65 	 	
0.075 	2 	8 	0 	8 	0 	10 	0 	8 	2 	8 	0 	5 	0 	25 	2 	0
d60 	13 	6 	35 	0.25 	25 	6 	40 	1.2 	10 	5 	15 	7 	35 	0.15	2 	NaN
d10 	0.7 	0.1 	1 	0.08 	1.2 	0.075 	1.2 	0.085 	0.6 	0.09	2.5 	0.3 	1.2 	NaN 	0.658	0.466
Content Uniformity 	19 	60 	35 	3 	21 	80 	33 	14 	17 	56 	6 	23 	29 	 	3 	NaN
Porosity (Vukovic) 	0.26	0.26	0.40 	0.26 	0.26 	0.26 	0.27 	0.26 	0.27	0.26	0.34 	0.26 	0.26	 	0.40 	0.25
Mean porosity (Vukovic)	0.26	0.26	0.33 	0.33 	0.26 	0.26 	0.26 	0.26 	0.26	0.26	0.3 	0.3 	0.26	0.26	0.38 	0.38
K(Hazen)(mm/hr) 	1764	36 	3600 	23 	5184 	20 	5184 	26 	1296	29 	22500	324 	5184	NaN 	62500	
Mean K(hazen)(mm/hr) 	900 	900 	1812 	1812 	2602 	2602 	2605 	2605 	663 	663 	11412	11412	NaN 	NaN 	62500	62500
Porosity values were calculated based on the coefficient of uniformity (CU)Vuković, Milan and Soro, Andjelko Determination of hydraulic conductivity of porous media from grain-size composition. Water Resources Publications, Littleton, Colo, 1992.Odong, J. (2007). Evaluation of Empirical Formulae for Determination of Hydraulic Conductivity based on Grain-Size Analysis. Journal of American Science, 3(3). Retrieved from http://www.jofamericanscience.org/journals/am-sci/0303/10-0284-Odong-Evaluation-am.pdfZhang, S. (2017). Relationship between Particle Size Distribution and Porosity in Dump Leaching. the University of British Columbia. Retrieved from https://open.library.ubc.ca/collections/ubctheses/24/items/1.0357233:
n=0.255\left ( 1+0.83^{C_{U}} \right )
Where coefficient of uniformity is the ratio of the 60th and 10th percentile grain sizes:
C_U=\frac{d_{60}}{d_{10}}
Permeability (K) was estimated from the 10th percentile grain size using the Hazen formula. 
==References==
Category: Materials