Water permeability substrate material specifications The material of the water-permeable base layer is mainly gravel, which is selected by the conditions of the angularity, interpenetration, and hardness of the gravel. Crushed stone materials should be made of tough, wear-resistant broken granite or limestone; do not mix different soft and hard stones. The gravel material should be a multi-cornered block, clean and soil-free, stone-free and weathering-free stone. Gravel material should meet the following conditions. The compressive strength should not be less than 80MPa; The content of soft particles should be less than 5%; Mud content should be less than 2%; Flat and slender (1:2) gravel content should be less than 20%; Gravel rules are 30~70mm and caulking material specifications are 15~25mm. The amount of gravel used is shown in Table 1 below. The composition of gravel particles is shown in Table II. Crushed stone specifications and consumption table 1 Gravel thickness (cm) Crushed stone specifications (cm) Caulking amount (m3/100m2) 1.5~2.5cm 1.0~1.5cm 8 3~6 1.6 1.2 10 4~7 2.5 1.6 Crushed stone composition table 2 Standard size (mm) Percentage of mass passing through the following mesh (%) 100 80 60 40 30 25 20 10 40~80 100 90~100 25~60 0~15 - 0~5 - - 30~60 100 90~100 25~50 0~15 - 0~5 - Cat Feather Toys,Feathers Cat Teaser Toy,Electric Cat Feather Toy,Pet Cat Toys Ningbo Movepeak Pet Supplies Co.,LTD. , https://www.pet-supplies-factory.com