Aggregate: Type  "A"
Calcareous/Siliceous Gravel

NP indicates unit dimension is undersized for required thickness.
(#)  indicates minimum ASTM C-90 dimensions required.

NOMINAL SIZE CMU REQUIRED EQUIVELENT  INCHES HOURLY RATING PERCENT SOLID OF SOLID  THICKNESS ONE HOUR  RATING 4"CMU 77.24% 2.80 6"CMU 49.78% 2.80 8"CMU (#) 45.70% (#) 3.48 10"CMU (#) 44.00% (#) 4.24 12"CMU (#) 41.80% (#) 4.86 90 MINUTE  RATING 4"CMU 99.31% 3.60 6"CMU 64.00% 3.60 8"CMU 47.12% 3.60 10"CMU (#) 44.00% (#) 4.24 12"CMU (#) 41.80% (#) 4.86 2 HOUR  RATING 4"CMU NP NP 6"CMU 74.67% 4.20 8"CMU 55.08% 4.20 10"CMU (#) 44.00% (#) 4.24 12"CMU (#) 41.80% (#) 4.86 3 HOUR  RATING 4"CMU NP NP 6"CMU 94.22% 5.30 8"CMU 69.51% 5.30 10"CMU 55.06% 5.30 12"CMU (#) 41.80% (#) 4.86 4 HOUR  RATING 4"CMU NP NP 6"CMU NP NP 8"CMU 81.31% 6.20 10"CMU 64.42% 6.20 12"CMU 53.33% 6.20