▎ 摘　　要

NOVELTY - A low-grade concrete mixed with stone powder comprises 219-281 pts. wt. cement, 29-37 pts. wt. mineral powder, 0-35 pts. wt. fly ash, 12-50 pts. wt. stone powder, 781-801 pts. wt. sand, 975-1062 pts. wt. gravel, 3.17-4.81 pts. wt. water reducing agent, and 179-190 pts. wt. water. USE - Low-grade concrete for use as a cushion layer or non-trunk road of a building structure and a road. ADVANTAGE - The application partially or completely replaces the fly ash as admixture, it can relieve the shortage of existing mineral admixture fly ash supply, reduce the production cost of the concrete, and add proper reducing low grade concrete to the compression strength powder, making it meet the national standard, and improving the workability of concrete. The stone powder has a certain filling effect, cement, stone powder and fly ash particles are filled with effect, the gap between the particles is reduced, and the gap water in the concrete is reduced. The modified polypropylene fiber in the application is added with low-grade concrete, effectively preventing segregation of concrete, blocking the concrete capillary crack, preventing concrete shrinking crack phenomenon, and further improving the impermeability and anti-cracking performance of concrete so as to improve the service life. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of low grade concrete, which involves (1) mixing and stirring cement, fly ash, stone powder and water to obtain a mixture (M1), and (2) mixing mineral powder, sand, gravel and water reducing agent, adding the mixture (M1), mixing and stirring to obtain low-grade concrete.