| 摘要 |
FIELD: manufacture of building materials; production of cement-water suspension and products on its base: cement stone, mortars and concretes. ^ SUBSTANCE: proposed method makes it possible to ensure activation of cement particles from cement-water suspension under conditions of statically smooth distribution of water in suspension over surface of cement fractions when surfaces of coarse, medium and fine particles adsorb such amount of water which they are able to hold at mixing. Proposed method includes mixing of hydraulic binder, mainly cement, with water or with filler and water at physico-chemical activation of cement in composition of cement-water suspension obtained in mixing unit in field of centrifugal forces. Activation is performed with cavitation intensified by blowing and bubbling the suspension with compressed air at regulation of mixing time. Magnitudes of cavitation ϕ are within range of 3.8 to 0.6.10-4. Cavitation number is determined from the following formula: ϕ=[(k1Delta+k2DeltaP)eta]/2pi2gp2R3n,,where k1 is coefficient of loss of pressure head in mixing unit at cavitation which is equal to 0.55-0.8; DeltaH is difference between hydraulic pressure head in mixing unit and pressure of saturated steam in cavities at 20°C equal to 0.03 MPa characterizing the cavitation field and selected within 0.25-1.2 MPa; k2 is coefficient of loss of pressure head of blown compressed air which is equal to 0.5 in the average; DeltaP is difference between pressure of blown compressed air and pressure of saturated steam in cavities selected within 100-250 kPa; eta is present viscosity of cement-water suspension being prepared or products on its base which is maintained within 16-1770 Pa.s and within 20-130 Pa.s during bubbling; rho is present density of said cement-water suspension or products on its base, kg/cm3; g is free fall acceleration equal to 9.81 m/s2 ;Pi is equal to 3.14; R is present radius of said field of centrifugal forces selected within 0.3-1.2 m; n is frequency of rotation of working member of mixing unit selected within 300-6000 rev/min or 5-100 s-1; activation of suspension is continued till initial cement hydration degree reaches at least 2.5 mass-% by criterion of increment of losses at calcination from beginning of addition of water to concrete mix till its setting. ^ EFFECT: enhanced efficiency. ^ 15 cl, 2 dwg, 2 tbl |
