3. Methods 3.1 Raw materials It includes cement, coarse aggregate, fly ash, fine aggregate and admixture. The specific selection parameters are as follows:Cement The medium thermal Portland cement of P.MH42.5. Table 1 lists the test results for its physical and mechanical properties.coarse aggregate. The secondary aggregate grading stone. Table 2 lists its performance test results.Fly ash. The test results of Class F Grade I fly ash are shown in Table 3.Fine aggregate. The natural gradation limestone artificial sand is produced by the sandstone processing system of certain hydropower station construction project, with the stone powder content of 15%. By artificial washing or adding stone powder, six artificial sands with stone powder contents of 12%, 18%, 20%, 22%, 25% and 28% were obtained.Admixtures. PCA-1 retarding polycarboxylic acid high performance water reducing agent; GYQ (I) air entraining agent.