The Manufacture Of Activated Silicate Cements And Its Microstructure Research

The strength activation of silicate cements were studied by different kinds of activators. By changing the activator and amounts mixing material, the activated slag silicate cement, fly ash silicate cement and compound silicate cement were produced. The hydration performance and strength were analyzed. Also the hydration and harden mechanism were studied from microstructure by X ray, Scanning Electronic Microscopy, differential thermal analysis (DTA), DSC, etc. atom force microscopy (AFM). The economical and social benefits were also discussed.Through the production of activated silicate cements, the results show: (1)the performance of activated Grade 32.5 slag cement has remarkably improved; the strength grade improves one grade. The 3 days flexural strength and compressive strength increase 37. 5% and 63. 3% respectively. 28 days flexural strength and compressive strength increase 9.09% and 29.07%, respectively. The finess and specific surface area enhance 5. 57%, the early strength improves and it has great effect on aiding grinding. (2) the mixing amount of activated grade 32. 5 fly ash cement can be up to 35%, early strength increases greatly, and it uses much of industrial by-products. The 3 days flexural strength increases 12.8%, compressive strength increases 12. 5%; and these of 3 days increases 4. 41% and 7. 23% respectively. (3) the early strength of activated grade 32.5 compound silicate cement improves greatly. It also has good effect of aiding grinding. The maximum mixing amount can be 60%. Its bending strength and compressive strength of 3 days increase by 215% and 39.4%, and these of 28 days 27.8% and 6.4% respectively.Through the analyzing of modern test means on activated silicatecements, the results show that hydration reaction occurs early and much hydrates of ettringite, Ca(0H)2 etc appears. The SEM photographs of 3 d hydrates show that the structure is packed closely and it appears flocculating. The IR photographs of 3 d show the wavenumber has displacements, and this explains the crystal structure has changed. The XRD patterns of 3 d hydrates show that the hydrates like Ca(0H)2 has changed. The DTA curves show the reaction heat reduces. All the changes of microstructure should be studied further.Through the technical and economical analyzing, it shows that the production of activated silicate cements have obvious economic benefits. The cost of activated grade 32.5 slag silicate cement, fly ash cement and compound cement is calculated. We can gain profits of 4. 85 yuan, 3. 75 yuan, and 22. 97 yuan each ton. Especially the much use of fly ash, it accords with the nation policy of using resources. And this also has great social benefits. It benefits to reduce environmental pollution, and it has obvious contribution to green production and continuable development.