BASICS OF CONCRETE SCIENCE - CHAPTER 4 ppsx

... formula: (4. 4) ,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 ... formula: ( ) (4. 7) ,5.0W/CКR − = where R- strength of concrete; C/W– cement-water ratio; K- coefficient. After treatment of experimental researches B.Skramta...

Ngày tải lên: 09/08/2014, 14:21

... 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...

Ngày tải lên: 09/08/2014, 14:21

... SnO 2 BeO - - - - - MgO - - - - CaO ++ ++ ++ ++ ++ ++ ++ ZnO - - - SrO ++ ++ ++ + + + + CdO - - - - - BaO ++ ++ ++ ++ ++ ++ ++ Note: fixed (++) and predicted (+) existence of binding ... range, %: 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...

Ngày tải lên: 09/08/2014, 14:21

... (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...

Ngày tải lên: 09/08/2014, 14:21

... 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 ... cement; 2- capillary pores; 3- cement hydrate gel a b 67 3 .4. Optimization of concrete structure Concrete structure is a cover-up of its str...

Ngày tải lên: 09/08/2014, 14:21

... deformation of shrinkage. 89 On the idealized chart of compression of cement stone it is possible to select three basic areas: a-b- absence of cracks in the structure of cement stone; b- c- appearance ... watertightness of concrete. Amount of shrinkage of cement paste and concrete depends on age of hardening, composition, specific surface and quantity of cement, q...

Ngày tải lên: 09/08/2014, 14:21

... 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 ... strength, rate of hardening, time and conditions of concrete hardening. 125 Durability of concrete in the terms of influence of aggressive environment is provi...

Ngày tải lên: 09/08/2014, 14:21

... equality of volume of the concrete mix to the sum of absolute volumes of the initial components of concrete, the second - conformity of volume of the cement - sandy paste (mortar) to volume of voids ... 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 1.38 300 – – 1.3 1.36 1 .42 – 350 – 1.32 1.38 1 .44 – – 40 0 1.31...

Ngày tải lên: 09/08/2014, 14:21

... (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 ... fine-grained concrete, high-strength concrete, concrete, modified by polymer admixtures and fiber reinforced concrete, concrete for special purposes – hydrotechnical,...

Ngày tải lên: 09/08/2014, 14:21

... Structural-heat insulating 50 0-1 40 0 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 173 Fig. 9.1 Effect of bulk density of aggregate ... gradation of the aggregate make influence on formation of structure and properties of no-fines concrete. Volume of voids between grains also depends...

Ngày tải lên: 09/08/2014, 14:21