Research On Hydration And Application Of Cement Based Materials With Double Replacement Of Fly Ash And Desulphurization Gypsum

This paper based on the project of＂The comprehensive development andutilization of fly ash and desulfurization gypsum from coal fired power plantindustrial solid waste＂, with the using of micro test and macro test, the hydrationprocesses of fly ash-desulfurization gypsum double mixing cement base material andin different modifier were studied, the Influence factors of hydration process wereanalyzed, hydration mechanism were researched, the main technical performance ofdried mortar and concrete were test studied , entity engineering application wereintroduced at last. This study to fly ash-desulfurization gypsum double mixing cementbase material hydration mechanism and the main technical performance of driedmortar and concrete, has the important theoretical and practical significance. Theseachievements of the paper are as follows:1. Based on the fly ash-cement base material hydration mechanism analysis,the hydration mechanism of fly ash-desulfurization gypsum double mixing cementbase material Was put forward. The Hydration reaction essences were cement clinkerhydration, fly ash-desulfurization gypsum stimulating each other activity, and heprocess of desulfurization gypsum crystal chromatography.2. The influence of alkaline modifier NaOH, sulfate modifier Na₂SO₄, chlorinesalt modified CaCl2to the hydration processes of cement based materials with doublereplacement of fly ash and desulphurization gypsum, was theory researched. Throughthe plastic sand strength test to verify the effect, and then puts forward the modifierblends with solutions.3. With the using of micro test and macro test, the Influence factors of cementbased materials with double replacement of fly ash and desulphurization gypsum, hecement type, fly ash-desulfurization gypsum and mixed quantity scale, water-binderratio, curing temperature and so on, was researched. These laying foundation topreparation and application of cement based materials with double replacement of flyash and desulphurization gypsum design.4. Fly ash-desulfurization gypsum double mixed composite cement dry mortarwas developed, the ratio of Fly ash- desulfurization gypsum can be up to 75%, thebonding mortar meets M10 level requirement, plaster mortar meets M7.5 levelrequirement, and workability is excellent, dry shrinkage rate is lower than cementbased material, having good cracking resistance, usd in entity engineering successfully. Dry mortar mixing ration is recommend, C：FA：FGD：S=0.15：0.60：0.25：3, water/cement is 0.6,and mixed with 0.1% MC and 0.4% fiber.5. Fly ash-desulfurization gypsum pavement concrete was developed, Mixingwith 20% 40% Fly ash-desulfurization gypsum, 7days concrete compressivestrength can reach 28.1 to32.3 MPa, Flexural strength can reach 3.2 to 4.3MPa;28days concrete compressive strength can reach41.1 to47.7MPa, achieving C35grade, Concrete workability, mechanical properties and volume stability is fine, usingin entity engineering successfully.