Fire Protection Of Wooden Storage Containers For Explosive And Pyrotechnic Products

Analysis of the emergency storage facilities for explosive and pyrotechnic products is conducted. It is established that one of the greatest risks is their flammability. Since the explosive and pyrotechnic products are stored in wooden containers, there is a need for their fire protection. To determine the efficiency of fire resistant containers for packaging explosive products it is designed operating range of testing method. This method is necessary to establish mass loss, measuring the growth temperature and response time of the squibs. The results of the efficiency of the fire retardant treatment of wood and organic coated coating showed that when exposed to high–temperature destruction of the construction detonation of the squibs didn\u27t happen.Tests to determine the quality of the fire retardant treatment of wood coatings showed that the temperature on the inner surfaces of the untreated sample was more than 760 ºC, samples with fire retardant coatings – no more than 128 °C. The conclusion of the feasibility of using fire–retardants is not based on inorganic and organic binders for the treatment of wooden structures.Method of determining the fire protection is used to assess the efficiency of the fire protection of wooden structures. Method comprises determining the ratio of the sample rate of burnout, the temperature increment and the ignition time of untreated and treated samples. As a result of the firing testing it is established a speed burnout reduction of samples of the container with treated coatings compared with untreated coatings is decreased by 2,4-4,4 times and respectively fire protection efficiency factor of treated samples of the container compared to untreated is increased by1.8-4.1 times

Determining the Effect of the Composition of an Aluminosilicate Binder on the Rheotechnological Properties of Adhesives for Wood

Main rheotechnological properties of aluminosilicate adhesives for gluing wood arrays have been investigated. It was established that for adhesives based on the alkaline aluminosilicate binding agent with a composition of Na2O×Al2O3×4.5SiO2×17.5H2O dynamic viscosity in the range of speeds from 0 to 200 RPM varies from 6.933 sP to 368.4 Sp, and the mean plastic viscosity takes the magnitude of 86.27 sP. At the same value of surface tension and cohesive work, the smallest angle of wetting (cosQ=0.7973) and the largest coefficients of wetting (s=0.8986) and spreadability (f=–6.5 mN/m), as well as the work of adhesion forces (Wa=58.23 mN/m), wetting (Wa=58.23 mN/m), are demonstrated by beech backing, followed by alder, ash, pine, birch, and oak.For adhesives based on the alkaline aluminosilicate binding agent with a composition of Na2O×Al2O3×6SiO2×20H2O dynamic viscosity in the speed range from 0 to 200 RPM varies from 5.340 sP to 374.4 sP, and the mean plastic viscosity takes the magnitude of 85.72 sP. At the same value of surface tension and cohesive work, the smallest angle of wetting (cosQ=0.5876) and the largest coefficients of wetting (s=0.7938) and spreadability (f=–19.34 mN/m), as well as the work of adhesion forces (Wa=74.46 mN/m), wetting (Ww=27.56 mN/m), are demonstrated by alder backing, followed by pine, oak, birch, beech, and ash.For the adhesive with a composition of Na2O×Al2O3×4.5SiO2×17.5H2O, at low values of shear rate, from 0.0378 to 1.05 1/sec, the shear force increases from 26.21 dyne/cm2 to 48.64 dyne/cm2. The data obtained significantly exceed the same indicators for a liquid glass at high shear rates, from 14 to 39 1/sec. For the adhesive with a composition of Na2O×Al2O3×6SiO2×20H2O, at low shear speeds there is a sharp increase in the shear effort, from 40 to 110 dyne cm2. This is due to the dispersion processes in the silica component. At an increase in the shear speed values from 5 to 42 1/sec, the shear effort increases from 110 to 158 dyne/cm2. This relates to the stabilization of viscosity values with the formation of a homogeneous adhesive structur

Determining the Effect of the Composition of an Aluminosilicate Binder on the Rheotechnological Properties of Adhesives for Wood

Main rheotechnological properties of aluminosilicate adhesives for gluing wood arrays have been investigated. It was established that for adhesives based on the alkaline aluminosilicate binding agent with a composition of Na2O×Al2O3×4.5SiO2×17.5H2O dynamic viscosity in the range of speeds from 0 to 200 RPM varies from 6.933 sP to 368.4 Sp, and the mean plastic viscosity takes the magnitude of 86.27 sP. At the same value of surface tension and cohesive work, the smallest angle of wetting (cosQ=0.7973) and the largest coefficients of wetting (s=0.8986) and spreadability (f=–6.5 mN/m), as well as the work of adhesion forces (Wa=58.23 mN/m), wetting (Wa=58.23 mN/m), are demonstrated by beech backing, followed by alder, ash, pine, birch, and oak.For adhesives based on the alkaline aluminosilicate binding agent with a composition of Na2O×Al2O3×6SiO2×20H2O dynamic viscosity in the speed range from 0 to 200 RPM varies from 5.340 sP to 374.4 sP, and the mean plastic viscosity takes the magnitude of 85.72 sP. At the same value of surface tension and cohesive work, the smallest angle of wetting (cosQ=0.5876) and the largest coefficients of wetting (s=0.7938) and spreadability (f=–19.34 mN/m), as well as the work of adhesion forces (Wa=74.46 mN/m), wetting (Ww=27.56 mN/m), are demonstrated by alder backing, followed by pine, oak, birch, beech, and ash.For the adhesive with a composition of Na2O×Al2O3×4.5SiO2×17.5H2O, at low values of shear rate, from 0.0378 to 1.05 1/sec, the shear force increases from 26.21 dyne/cm2 to 48.64 dyne/cm2. The data obtained significantly exceed the same indicators for a liquid glass at high shear rates, from 14 to 39 1/sec. For the adhesive with a composition of Na2O×Al2O3×6SiO2×20H2O, at low shear speeds there is a sharp increase in the shear effort, from 40 to 110 dyne cm2. This is due to the dispersion processes in the silica component. At an increase in the shear speed values from 5 to 42 1/sec, the shear effort increases from 110 to 158 dyne/cm2. This relates to the stabilization of viscosity values with the formation of a homogeneous adhesive structur

Investigation of Adhesive Properties of Barrier-type Geocement-based Coatings

The results of the adhesive test of the research object – barrier-type geocement-based coating applied to metal polymer film, formed as a result of redox reaction of «Contrrust» rust converter and metal corrosion products are shown in the article. Despite the diametrically opposite pH of the two substrates, traces of rejection coating on the film, detachment and blistering, peeling and other defects aren't observed. The adhesive characteristics of the compositions included in the developed system of protective coating ««Contrrust» rust converter + barrier-type geocement-based coating» are determined: adhesive characteristics of the compositions included in the developed system of protective coatings: ««Contrrust» rust converter + barrier-type geocement-based coating»: adhesion for incision method of metal polymer film 117 microns thick to metal substrate is 1 point, and geocement coating to metal polymer film 550 and 168 microns thick is 3-4 and 1 point; adhesion for normal force separation method of metal polymer film 117 microns thick to the metal substrate is 1,8-6,1 MPa and barrier-type geocement-based coating applied to metal polymer film 550 microns thick is 1,7 MPa, which respectively in 3-10,2 and 2,83 times higher than regulations.Adhesive bond of geocement coatings to the metal polymer film consisting of water-resistance chelate complexes is so large that facilitates the joint separation of the two protective compositions from the surface of the metal substrate. The combined use of the above mentioned compositions contributes to a significant reduction in costs both in preparation and in terms of the painting works for metal structures

Influence of the CaO-containing Modifiers on the Properties of Alkaline Alyumosilicate Binders

The basis for ensuring the resistance of artificial stone based on alkaline aluminosilicate binders to variable environmental conditions is the formation of zeolite- and mica-like hydrate neo-formations.It is possible to control the structure forming processes and, as a result, the operational properties of alkaline hydro aluminum silicates using the variation of the ratio of basic oxides of the binder, dispersiveness of particles and hardening conditions. It was noted that in order to obtain high operational characteristics of a stone based on alkali aluminosilicate binders, there is a need for elevated temperature of their hardening.The research shows that it is possible to ensure water resistance of artificial stone at hardening under normal conditions at the expense of the modification of the binder by Ca-containing additives.The influence of CaO-containing modifiers of different phase composition on physical and mechanical properties of artificial stone based on alkali aluminosilicate binders was explored. Ensuring water resistance of artificial stone at its hardening under conditions of normal temperatures was proved by experimental research and its phase composition was studied. The kind and the optimal amount of CaO-containing modifiers to provide for operational properties of artificial stone were determined. The use of CaO-containing modifiers of alkaline aluminosilicate binders ensures the acceleration of their structure formation and contributes to an increase in water resistance and strength under normal conditions.The influence of CaO-containing modifiers of various morphological type on physical and mechanical properties of artificial stone based on alkaline aluminosilicate binders was studied. It was established that on day 28of hardening at ambient temperature of 20±2 °С regardless of the type of introduction of Ca-containing modifiers, artificial stone is characterized by strength at compression from 14.2 to 42.8 MPa with a coefficient of water resistance from 0.81 to 1.05 due to the formation in combustion products of the mixture of high- and low-base calcium hydro silicates and zeolite-like neo-formations of the hybrid type – calcium-sodium hydroaluminosilicates with an insignificant content of Na- and K-heulandite. It was shown that water resistance of artificial stone in the early periods of hardening at ambient temperature of 20±2 °С is ensured due to the formation in hydration products of the binder of high- and low-base calcium hydro silicates, formed due to hydration of Portland cement, ground slag and slaked lime. It is possible to accelerate the kinetics of strength gaining with ensuring the water resistance of artificial stone using liquid glass with silicate module of 2.0–2.6 and lime content in the amount of 2.0–3.0 % percent of the weight of alkaline aluminosilicate binder as an alkaline component. It was noted that hydraulic activity of Ca-containing modifiers decreases in the series Slag>Са(ОН)2>СаСО3>Portland cement>Alumina cemen

Influence of the Ratio of Oxides and Temperature on the Structure Formation of Alkaline Hydro-aluminosilicates

In the course of optimization of compositions of alkaline hydro-aluminosilicates of general structural formula – (0,7÷1Na2O+0÷0,3K2O)·Al2O3·(2÷7)SiO2·nH2O, it is established that the phase composition of artificial stone depends more on the ratio of basic oxides; the temperature of hardening in the range of 20÷80 °С increases the speed of structure formation of zeolite-like phases.A determining factor of influence on the type of hydrated new formations is the ratio of SiO2/Al2O3; its increase leads to the creation of zeolite-like phases with high content of silica in its composition. At hardening of alkaline hydro-aluminosilicate of the given structural forms under standard conditions of hardening, providing for a high degree of crystallinity of structure, optimal is the ratio SiO2/Al2O3=4÷5.Introduction of potassium ions into the composition of hydro-aluminosilicate contributes to obtaining potassium and sodium–potassium zeolite–like new formations and to increasing the degree of crystallinity of the indicated phases. To accelerate the structure formation of alkaline hydro-aluminosilicate under standard conditions of hardening, it is necessary to introduce potassium oxide at K2O/R2O=0,15÷0,3.With an increase in the temperature of hardening of alkaline hydro-aluminosilicate from 20 to 80 °, the phase composition of artificial stone remains practically unchanged; however, this leads to an increase in the velocity of structure formation and the degree of crystallinity of artificial stone.As a result of optimization, we determined optimum structural formula of hydro-aluminosilicate (0,8Na2O+0,2K2O)·Al2O3·4,5SiO2·nH2O, which makes it possible under standard conditions of hardening to obtain water-resistant artificial stone by the synthesis in the composition of hydrated new formations of zeolite-like minerals of the type of zeolite Na–A; sodium and potassium heulandite, as well as sodium potassium phillipsite

Investigation of Rheo-mechanical Properties of Cement Suspensions Activated in a Hydrodynamic Cavitator

The object of research is cement suspensions activated in a hydrodynamic cavitator. One of the most problematic places of the proposed method of activation is the slowing of the kinetics of the strength of astringents on days 2 and 7 of hardening. It is possible to speed up the set of strength by studying the processes of structure formation occurring in activated suspensions and hardening mixtures, and also to enhance physical effects by improving the design of the cavitator and the mixing chamber.During the study, activated water and 10 % cement-water suspension are used. After 10 minutes of cavitation treatment at pressures of 0.63–1.4 MPa and a temperature of 28–32 °C, the pH of the medium increases (pH+7.56) and decreases by a factor of 10.38 times the dynamic viscosity of the suspensions. This is due to the fact that the increase in pressure and temperature in the cement-water suspension contributes to the intensification of the dispersion of cement particles in the frequency range 700–800 Hz and the passage of intensive mass-transfer processes in the frequency range 1.9–3.5 kHz, leading to the formation of primary crystallization structures.Due to this, it is possible to obtain dilatant liquids with a viscosity of 160 to 273.5 cP and control the rate of agitation in the speed range from 50 to 200 min-1. Compared to similar activation methods, the approach under study provides an increase in brand strength of 1.14 times compared to an unactivated cement system and contributes to a decrease in the amount of Portland cement from 10 to 14 %

Evaluation of Effectiveness of Wood Fire Protection Upon Exposure to Flame of Magnesium

An analysis of unforeseen fires and explosions at ammunition storage sites was conducted and it was found that one of the biggest risks is their fire hazard as storage of such products is realized using wood, both in building construction and packaging products, and necessity of efficient fire retardant treatment was established. To determine efficiency when developing fire retardant coatings studies were conducted for the determination of the combustibility group of wood in terms of weight loss and raise of the flue gas temperature, and it was found that when treating of wood with coatings, the mass loss did not exceed 5 % and the temperature did not exceed 260 ºC. The results of the determination of the efficiency of fire retardant treatment of wood with geocement and organic­mineral coatings showed that the material burn­out and structural failure did not occur when exposed to high­temperature flame. Studies to determine the quality of the fire retardant treatment of wood with a coating have shown that the rate of wood charring in case of untreated sample was 2 mm/min, and in case of samples treated with fire retardant agents it did not exceed 0.5 mm/min which allowed us to conclude as to feasibility of the use of fire retardants based on inorganic and organic binding materials for the treatment of wooden structures. To assess the effectiveness of the fire retardant treatment of structures made of wood, the duration of magnesium flame impingement on the surface of the flame of wood treated with fire retardant agents was studied, and it was found that the sample treated with organic­mineral protective coating prevented impact of high temperature and rate of wood charring more efficiently due to the creation of the swollen coke layer than coatings based on inorganic compounds, the mechanism of action of which was aimed at heat isolation