Method for manufacturing manhole cover or water grate cover

The invention discloses a method for manufacturing a cement concrete manhole cover or a water grate cover by using an autoclaving process, belongs to the technical field of building materials and relates to the method, which comprises the following steps of: taking cement, sand, stones, additives, admixtures, steel fibers, water, lime and grammite as main raw materials, wherein the admixtures are one or more of slag powder, fly ash, quartz sand powder, steel slag and other levigated silicon-containing industrial solid wastes or tailings powder; uniformly mixing the cement, sand, stones, additives, admixtures, steel fibers, water, lime and grammite in certain proportion; placing a reinforcement cage into a mould of the manhole cover or the water grate cover; pouring the concrete mixture into the mould for molding, maintaining the mould at the normal temperature or under the condition of steam for 0.5 hour to 28 days; and autoclaving the mould at the constant temperature under an autoclaving condition (steam pressure is 0.5 to 1.5 MPa) for 0.5 to 16 hours to manufacture the manhole cover or the water grate cover. The autoclaved manhole cover or water grate cover produced by the method has the characteristics of high strength, little deformation and high durability; and the method has the advantages of making good use of solid wastes and achieving remarkable economic effect and social effect.