BASICS OF CONCRETE SCIENCE - CHAPTER 3 docx

... forming Influence of chemical admixtures Fig .3. 10. Kinetics of change of level of hydration of cement silicate phase: 1- without admixtures; 2- calcium nitrite-nitrate (3% ); 3- calcium nitrite-nitrate–chloride ... grain of cement; 2- capillary pores; 3- cement hydrate gel a b 67 3. 4. Optimization of concrete structure Concrete structure is a cover-u...

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... (2. 7-2 .9): d – size of particles of the given fraction of aggregate; D – maximum particle-size of aggregate; A – coefficient equal 8-1 2 depending on the kind of aggregate and plasticity of concrete ... frequency of vibrations. 42 Fig. 2.1. Change of viscidly-plastic properties of concrete mixture depending on tensions: a – change of structural viscosity; b –...

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... manuscript of book of Doct. of Tech. Science, Prof. L. Dvorkin and Doct. of Tech. Science O. Dvorkin Basics of Concrete Science By now concrete science became one of the fundamental material sciences, ... manuscript of book of Doct. of Tech. Science, Prof. L. Dvorkin and Doct. of Tech. Science O. Dvorkin Basics of Concrete Science Basically conc...

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... %: Са - 63 66 MgO- 0.5 5 SiO 2 - 22 24 SO 3 - 0 .3 1 Al 2 O 3 - 4 8 Na 2 O+K 2 O- 0.4 1 Fe 2 O 3 - 2 4 TiO 2 +Cr 2 O 3 - 0.2 0.5 Fig. 1.2. Crystals of alite Fig. 1 .3. Crystals of belite 33 Classification ... SnO 2 BeO - - - - - MgO - - - - CaO ++ ++ ++ ++ ++ ++ ++ ZnO - - - SrO ++ ++ ++ + + + + CdO...

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... ,kdd/Е 2/1 срср − =ν=σ where - tensile stress; E- modulus of elasticity; - effective energy of destruction; d as - average size of a crystal; ( ) 2/1 Ek − ν= - coefficient of viscidity of destruction. Strength of concrete ... strength of concrete; k – strength coefficient, A – constant value, x – ratio between volume of water and volume of cement. Graf of...

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... influencing of size of unit, humidity of environment and age of concrete in the moment of loading began. 99 Fig.5.7. Effect of conditions of loading on magnitude of creep for typical normal-weight concrete ... watertightness of concrete. Amount of shrinkage of cement paste and concrete depends on age of hardening, composition, specific surface and quantity...

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... and water-cement ratio (W/C) of concrete: 1 – Air-entrained concrete; 2 - Non-air-entrained concrete W/C Cycles of freezing and thawing Mineral admixtures in frost-resistant concrete especially ... К f and η w - coefficient of filtration and water viscosity. 124 Ettringite appears in the cement stone under the action of sulfate water: ( ) OH31СаSO3OAlСа 3 ОH19OH...

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... mixes) Value of α at water-cement ratio Cement content, kg/m 3 0 .3 0.4 0.5 0.6 0.7 0.8 250 – – – 1.26 1 .32 1 .38 30 0 – – 1 .3 1 .36 1.42 – 35 0 – 1 .32 1 .38 1.44 – – 400 1 .31 1.4 1.45 – – – 500 ... 10, 15, 20, 30 , 40, 60, 80 и 150 mm) Slump, cm Amount of water, kg/m 3 1 43 7.4. Correction of design concrete compositions Inevitable deviations of actual index...

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... (R cmp ): 1 - R f of sand concrete, 2 - R f of ordinary concrete, 3 – R t of sand concrete R t , R f , МПа R cmp , МПа 10 20 30 40 50 60 70 80 90 100 10 9 8 7 6 5 4 3 2 ... (Fig.8 .3) . Fig.8 .3 Relationship between water amount of concrete mixes (slump 1-4 cm) and BLWR content (A), water-cement ratio W/C (B) W/C BLWR, kg/m 3...

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... Structural-heat insulating 50 0-1 400 3. 5-1 0 0.1 7-0 .40 For enclosing structures Structural 140 0-1 800 1 5-5 0 0.5 8-0 .4 For load-carrying structures 1 73 Fig. 9.1 Effect of bulk density of aggregate ... cellular concrete А ≈10, for non-autoclaved cellular concrete А ≈7,5 8,5. 1 83 9.5. Cellular concrete Cellular concrete (gas concrete) has been sugge...

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