Impermeable concrete and preparation process thereof

The invention discloses impervious concrete and a preparation process thereof, and relates to the field of concrete. The impervious concrete is prepared from the following raw materials in parts by weight: 380 to 460 parts of cement, 120 to 200 parts of fly ash, 650 to 800 parts of sand, 1000 to 1200 parts of stone, 10 to 20 parts of water reducing agent, 50 to 70 parts of expanding agent, 50 to 65 parts of modified nano silicon dioxide, 12 to 20 parts of composite fiber and 140 to 200 parts of water. The modified nano silicon dioxide comprises the following raw materials in parts by weight: 58-70 parts of nano silicon dioxide, 12-18 parts of a silane coupling agent, 2-5 parts of sodium silicate and 180-240 parts of deionized water; the composite fiber consists of modified polyvinyl alcohol fiber, glass fiber and steel fiber, wherein the modified polyvinyl alcohol fiber is prepared from the following raw materials: 36 to 48 parts of polyvinyl alcohol fiber, 1.7 to 3.5 parts of dioctyl adipate, 3 to 5 parts of