Bridge joint ultrahigh crack-resistance concrete and preparation method thereof

The invention relates to bridge joint ultrahigh crack-resistance concrete and a preparation method thereof. The concrete is prepared from cement, silica fume, diatomite, slag powder, red sandstone powder, polycarboxylate water reducing agent, steel fibers, polyacrylonitrile fibers and water. The preparation method comprises the following steps: uniformly mixing and stirring the cement, the slag powder and the red sandstone powder, and obtaining a cement mixture; then mixing the silica fume, the diatomite, the steel fibers and the polyacrylonitrile fibers, uniformly stirring, and obtaining a silica fume mixture; dissolving the polycarboxylate water reducing agent in water, and obtaining an additive aqueous solution; adding half of the additive aqueous solution into the cement mixture, and uniformly stirring; adding the remaining additive aqueous solution into the silica fume mixture, and uniformly stirring; and finally uniformly stirring the obtained mixture. The concrete of the invention has excellent crack r