Experimental research of structural organization of heat-insulating structural building materials for energy efficient buildings

Saı̈d, Sonia; Adilkhodjaev, Anvar; Kondrazhenko, Valeriy

doi:10.1051/e3sconf/20199702009

Cited by 12 publications

(7 citation statements)

References 4 publications

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“…The greatest difficulty is the choice of the initial water-cement ratio. It would seem that the / value should be taken equal to the [ / ] value for the test of normal density [1][2][3][4][5][6][7][8][9][10]. This is the condition for obtaining the maximum strength of concrete [11][12][13][14][15].…”

Section: Introductionmentioning

confidence: 99%

Fundamentals of property and compositions management concrete mix and concrete

et al. 2021

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The choice of the concrete composition following the set research tasks must satisfy the following requirements: 1-the maximum achievable strength on the given starting materials; 2-the required formability, corresponding to the accepted vibration-impact-peristaltic pressing; 3-a given level of dehydration of the concrete mixture, providing a residual W/C, close to the normal density of the cement paste. The accepted conditions are necessary and sufficient when using the physical-analytical method of designing concrete composition. Distinctive features of the method are the use of a large amount of information and the absence of arbitrary coefficients, technological constants, or parameters. The necessary data for the assignment of concrete compositions are determined according to the data of preliminary laboratory experiments, the given technological parameters of mechanisms and equipment, and the design characteristics of concrete and the structure to be formed. For the experimental study, a total of six independent information streams of initial data are used: 1-physical and mechanical properties of the constituents of concrete (Rc, ρc, ρc°, [V/C], рс, γ3, ρshch, γsh, γshch°); 2-laboratory data of tests of raw materials in concrete mix and concrete (a, b, c, Ku, A, B); 3-design characteristics of concrete mix and concrete (Rb, F, W, OK, Zh); 4-characteristics of the product to be concreted (V, h, l, μ); 5-technological characteristics of equipment, mechanisms, and devices (th, tb, TO, t0); 6-the cost per unit volume of raw materials (Sc, Cn, Ssh, Se, Sg). Obviously, the listed volume of initial information comprehensively characterizes the materials used and the conditions for forming the product. The previously developed technological conditions for forming concrete pipes, in addition to the above, require, when assigning the composition of concrete, to take into account the observance of the balance of masses in the concrete mixture and compacted, modified concrete. This should be manifested in checking the equation of absolute volumes for the original and compacted (dewatered) concrete.

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Section: Introductionmentioning

confidence: 99%

Fundamentals of property and compositions management concrete mix and concrete

et al. 2021

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“…The production of high-strength concrete by vibration-impact pressing is achieved by densely filling the intergranular space with cement paste and mortar with a simultaneous displacement of air bubbles, squeezing out part of the free water behind the portions of the compacted mixture [13][14][15][16][17][18][19]. In case of an unsuccessful selection of the composition of the concrete mixture, a rigid, practically incompressible frame of aggregate grains can form [20][21][22][23][24][25][26]. Note: Above the line is test results of concrete samples, compacted; vibro-impact pressing, under the line -the same, compacted by vibration, Where: R bvp is the strength of vibro-impact-peristaltic pressed concrete; R bv is the strength of vibro-compacted concrete.…”

Section: Introductionmentioning

confidence: 99%

Compressive strength properties of hyper-compacted concrete

2021

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The most important property of a concrete mix is concrete workability, i.e., the ability of the mixture to spread and take a given form while maintaining solidity and uniformity. The main influence on the workability of the concrete mixture is exerted by water consumption and, in part, cement consumption. Workability is determined by the mobility of the concrete mixture at the time of filling the mold and plasticity, i.e., the ability to deform without breaking the continuity. In the process of vibrating and pressing the concrete mixture placed in the mold, the total volume of the mixture changes until the pressure is balanced by the resistance forces. Deformation of concrete mix or, more precisely, freshly laid concrete with any compaction methods, including vibration compaction, is divided into elastic (reversible) and residual (irreversible). Residual deformations during vibration compaction occur as a result of water squeezing out and redistribution of aggregate fractions. Permanent deformation is part of the total. Its value at the same composition of the concrete mixture depends on the shape and size of the pressed sample. At the same time, it is noteworthy that after reaching a certain pressure, only elastic deformations will be characteristic of the freshly laid concrete mixture. So, A.D. Nikitin, in the course of the experiments, found that at a pressure of 2.2 MPa, the elastic moduli of the components of the concrete mixture have the following values: for cement paste - 0.16 · 104 MPa, aggregate - 4.5 · 104 MPa and air - 3 MPa ... After reaching a static pressure of 2.2 MPa, the compressible mixture showed only elastic deformation. This indicates that by the time the specified pressure was reached, the relative movement of the aggregates had ended, i.e., they are located most compactly.

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“…We have carried out a set of theoretical and practical research to study the effect of chemical additives in the water demand of the Portland cement and concrete made on its basis and the kinetics of hardening [7][8][9][10][11][12][13][14][15].…”

Section: Introductionmentioning

confidence: 99%

Influence of complex chemical additives on the rheological properties of cement paste and concrete mixture

Turgunbaev

Toxirov

2021

E3S Web Conf.

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The article studies the effect of complex chemical additives on the water demand of cement, the setting time of the cement paste, the consumption of cement and additives KJ-3 on the viscosity of the concrete mixture, and also determines the normal density of the cement paste without the additive and with the plasticizing additive and the rheological characteristics of the concrete mixture with the additive KJ- 3.

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Experimental research of structural organization of heat-insulating structural building materials for energy efficient buildings

Cited by 12 publications

References 4 publications

Fundamentals of property and compositions management concrete mix and concrete

Fundamentals of property and compositions management concrete mix and concrete

Compressive strength properties of hyper-compacted concrete

Influence of complex chemical additives on the rheological properties of cement paste and concrete mixture

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