Thermomechanical properties of zirconium dioxide concretes based on mechanochemical phosphate-containing binders

Thermomechanical properties of a highly refractory concrete based on ZrO₂ stabilized with 9–10 wt.% Y₂O₃ and phosphate-containing binder that is obtained by grinding ZrO₂ in an aqueous solution of H₃PO₄ are studied. The concrete obtained is distinguished by a low (about 1%) content of P₂O₅, high strength, and high resistance to heat. Thus it can be used as a reliable lining in high-temperature (>2300 K) heating units. Translated from Ogneupory i Tekhnicheskaya Keramika, No. 5, pp. 2–5, May, 1997.     

Metal resistance of refractory concretes based on phosphate binders

Conclusions We studied the resistance of the fused magnesite, corundum, and quartzite-based materials produced using phosphate binders to molten aluminum and copper. It was established that the materials based on fused magnesite and corundum are most stable in molten aluminum and the materials based on fused magnesite have the maximum resistance to molten copper.Translated from Ogneupory, No. 8, pp. 17–18, August, 1987.     

Strength properties of chamotte concretes based on phosphate binders

Conclusions The authors have investigated the strength properties of chamotte concretes based on phosphate binders over a wide range.They have shown the dependence of the compressive strength of the concretes on the type of phosphate binder used, the heat treatment temperature of the concrete, and its test temperature. Maximal compressive strength is exhibited by concretes roasted at 1450°C.They have established a relation between the physicochemical transitions taking place in a phosphate binder during heating and the strength characteristics of the concrete.Simultaneous introduction of phosphate binder and clay to the extent of 10–20% into chamotte concretes increases their strength at 20°C and during heating.Translated from Ogneupory, No. 6, pp. 32–36, June, 1979.     

Refractory concretes and coatings based on modified binder suspensions

The process of manufacturing protective coatings by means of deposition of aqueous suspensions is distinguished by the simplicity of the technological process and the low temperature at which it is realized. Phosphate-containing binders and concretes based on these types of binders increase the resistance of the particular material to corrosive media. Through their use it is possible to increase the service life of refractories.     

Properties of hot aluminosilicate concretes with various binders

Conclusions On the basis of results of a study of aluminosilicate concretes in the heated state, the following recommendations can be made for the use of these concretes, depending on the form of the binder and on the concentration of Al₂O₃ in the filler.Semiacid concrete in APB has fairly good strength and deformation properties, a high thermal-shock resistance, and can be used up to temperatures of 1350°C.Chamotte concrete in HAC is clearly not economical to manufacture. For performance, it can be totally replaced by chamotte concrete in AC or APB. The chamotte concrete in APB has better characteristics in the heated state than the concretes in other binders. It can be successfully used under conditions where there are sudden variations in the temperature and mechanical action.Aluminosilicate concretes in WG can reasonably be used in conditions of fairly intense abrasive action up to temperatures of 800°C. In places where the concrete is not subject to the action of molten metal or slag, it would not be reasonable to use concretes in WG containing >60% Al₂O₃.The high-alumina concretes in HAC have greater strength at high temperatures and therefore they must be used in those conditions; analogous concretes in APB can reasonably be used where there are sudden variations in temperature.The properties considered here of the concretes in HAC and APB are improved by increasing the concentration of Al₂O₃ and therefore the form of the filler for the concretes must be chosen in relation to the actual conditions of use.Translated from Ogneupory, No. 7, pp. 52–60, July, 1980.     

Carbon plastics based on thermoplastic polyimide binders modified with nanoparticles

Polyimides (PIs) crystallized from melts are promising thermally stable, heat-resistant plastics with high destruction viscosities. Nanocomposites that in turn serve as matrixes for carbon plastics can be obtained on the basis of PIs filled with carbon nanoparticles of various structures and morphologies. The presence of the composite-in-composite structure gives rise to the enhancement of dissipation properties of the polymer matrix in particular and to an increase in the crack resistance of the carbon plastic in general.     

High-alumina composite concretes and coatings based on modified phosphate binder suspensions

Coatings and materials based on aluminum phosphate suspensions are studied that have high strength in a raw state and are suitable for carrying out combined firing of a refractory and coating. An aluminum phosphate binder provides preparation of high physicomechanical properties in the firing temperature range. Use of traditional mixes with a protective aluminum phosphate coatings, and also ceramic concrete based on this binder provide increased material corrosion resistance, and consequently an increase in object operating life and period between repairs for metallurgical and glass melting units.     

Heat-resistant thermally insulating concretes with phosphate and aluminate binders

This article describes heat-resistant thermally insulating concrete mixtures and products with phosphate and aluminate binders, their properties, and the main processes used to make them. The thermophysical properties required of thermal insulation are obtained together with an increase in its strength thanks to the production of denser but less heat-conducting concretes with fillers composed of aluminum microspheres.     

Polymer composite materials based on thermoset epoxy binders modified with diamond-containing nanofillers

Structural features and physicochemical properties of promising diamond-containing modifier fillers for industrial polymers, namely, detonation nanodiamonds and nanodiamond soot, are considered. Experimental results demonstrating the possibility to create prepregs with the use of the carbon fabric 1.5 К and a detonation-diamond soot-modified binder based on the epoxy-resin mixture Epikote828/Epikote154 with an anhydride-type curing agent are presented. The rheological characteristics of the diamond-sootmodified binder remain practically the same after storage for 2 or 3 days at room temperature. The dependence of the glass-transition temperatures of the binders on the content of diamond soot in the concentration range 0.025–0.1 wt % is studied, and the correlation between these results and the mechanical characteristics (breaking strength, flexural strength, and crack resistance) of the cured binders is ascertained. Within the entire range of diamond-soot concentrations, the parameters of gelation are determined and the activation energies of this process are calculated.     

A constitutive equation for creep in polymer concretes and their resin binders

We present here a method for superposing creep measurements on polymer concrete (PC), taken at different temperatures, imposed stresses, and resin contents, onto master curves, which describe the respective responses of various PC systems and their resin binders, to compressive, tensile, and flexural loads. This treatment is extended to systems reinforced with chopped glass fiber and montmorillonite (MMT). The general applicability of this superposition is tested with creep measurements by other investigators under tensile, compressive, and flexural loads. The results make it possible to predict the long-term creep behavior of unfilled as well as reinforced glassy polymer systems at different temperatures and load conditions from limited, short-term data. Success of the multiple superposition suggests a generalized constitutive equation, which describes the creep compliance of these systems as a product of separable functions of each parameter in the form of shift factors for temperature (α_T), stress (α_σ), resin content (α_υ), fiber reinforcement (α_F), and MMT reinforcement (α_M): J(PC) = J_rα_Tα_σα_υα_Fα_Mt^m, where J_r is an appropriately chosen reference creep compliance. The time exponent m does not depend on the chemical nature of the polymer matrix.     

Coatings based on phosphate binders

Hydroxyapatite coatings based on phosphate binders are described. Their adhesion characteristics, the TCLE, and the effect of the temperature on the strength of the material of the coatings are presented. Coatings based on phosphate binders can present interest for specialists in electrochemistry and medicine. Translated from Steklo i Keramika, No. 6, pp. 28 – 29, June, 2000.     

Periclase concretes based on a silicate binder

OOO Gruppa Magnezit has developed a new generation of periclase cement-free concretes based on a MgO–SiO₂ binder with a service temperature from 1500 to 1700°C depending on filler composition. The technology assimilated makes it possible to prepare refractories of complex shape for lining elements of CBCM intermediate ladles and other units.     

Dynamic strength of polymer modified and fiber-reinforced concretes

For evaluating the performance of concrete construction such as foundation piles, a knowledge of the dynamic properties of concrete is also required. Some results of a study of concrete under dynamic impact loading are given in this paper. ø 100×200 mm cylindrical specimens were cast from plain and polymer cement concrete; some of the specimens were reinforced by polypropylene fibers also. The experimental details of the Hopkinson split-bar method used are described. The dynamic strength of concrete obtained was 40–45 % higher than the static strength. Compared to normal concrete, polymer cement concrete showed 30–35 % higher dynamic strength, and significantly higher energy transmission capacity.     

Intumescent polyurethane coatings with reduced flammability based on spirocyclic phosphate-containing polyols

Polyurethane coatings (PUC) with reduced flammability based on spirocyclic phosphate-containing polyols were synthesized from spirocyclic pentaerythritol di(phosphate acid monochlorides) (SPDPC). Some characteristic properties of the polyols and PUC were examined. The effects of the structure and the amount of contained phosphate on the properties of the polyols and PUC, especially on their resistance to combustion were studied. The spirocyclic phosphate-containing polyols are effective flame retardants for improving the resistance to combustion of PUC. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 471–475, 1997     

Principles of creating nanostructured binders based on HCBS

The combined interaction of factors is presented determining the principles of creating nanostructured binders based on highly concentrated ceramic binder systems (HCBS). Presence in HCBS of particles at a nano-level, and also intentional optimization of the spatial structure of this system has a comprehensive favorable effect on structure, rheotechnological properties of HCBS, and the technical and operating properties of materials prepared based upon them.     

改性结合剂对炭素捣打料性能的影响

以电煅无烟煤和冶金焦为骨料,中温煤沥青为结合剂,采用两类硝基芳烃化合物作为结合剂的改性添加剂,制备了炭素捣打料。结果表明:两类硝基芳烃化合物添加剂对结合剂起到了催化焦化缩聚作用,在不升高结合剂软化点的基础上,明显提高了结合剂的结焦值,从而有效地提高了炭素捣打料焙烧坯的体积密度和耐压强度,改善了低温炭素捣打料的使用性能。     

Evaluation of polyphosphoric acid on the performance of polymer modified asphalt binders

The aim of this research is to evaluate the effect of polyphosphoric acid (PPA) on the mechanical performance of styrene–butadiene–styrene (SBS) and styrene–butadiene–rubber (SBR) modified asphalt. Conventional properties, multiple stress creep recovery (MSCR), bending beam rheometer (BBR), and linear amplitude sweep (LAS) tests were conducted to evaluate the performance characteristics of asphalt at different PPA inclusions. Gel-permeation chromatography (GPC), saturates, aromatics, resins, and asphaltenes (SARA), and Fourier transform infrared (FTIR) were carried to reveal the molecular weight, component and infrared spectra of asphalt. Results showed that PPA hardened the asphalt, improved the rutting and fatigue performances of polymer modified asphalt (PMA) binder, but weakened the anti-cracking performances. Besides, storage stability had a significant improvement as the addition of PPA. The addition of PPA brought more macromolecules into asphalt and led to more high-average molecular weight compounds. Furthermore, PPA changed four component ratios of asphalt. Both PMA with or without PPA have similar absorption peaks. This may be due to absorption peak of PMA covered the changes in PPA modification process as the low content of PPA. 0.8% dosage of PPA may be considered optimum for composite modified binder combining the above experimental results for this binder source.