Clay Concrete Research Articles

Analysis of the functional efficiency of enclosing structures made of expanded clay concrete

The introduction discusses the main advantages and disadvantages of the use of structural and structural insulated lightweight concrete in the manufacture of load-bearing structures of buildings based on an analytical review of the work of various researchers. It is demonstrated that in the Republic of Belarus there is a sufficient production base for the mass production of expanded clay and expanded clay concrete products. For the special case of designing load-bearing walls made of expanded clay concrete blocks considered in the article, the features of their design are given (for example, reinforced concrete belt, reinforcement of masonry with grids). In the main part, on the example of the design of load-bearing external walls of a warehouse building, the achieved economic effect is demonstrated by the calculation method based on variant design. The results of the practical calculation performed within the framework of the variant design of the enclosing load-bearing walls of the building are presented. Two options are considered: the traditional solution is a masonry of silicate bricks with a thickness of 380 mm, an alternative option is a masonry of expanded clay concrete blocks with a thickness of 300 mm. It is established that the economic effect of the use of expanded clay concrete blocks is 9.3 % per 1 cubic meter. walls compared to the masonry of silicate bricks without taking into account the positive effect in the selection of foundation blocks and slabs, which is achieved as a result of reducing the own weight of the walls. The ways to improve the physical and mechanical characteristics of expanded clay concrete are proposed: the use of expanded clay gravel as a coarse aggregate, increase the strength of expanded clay gravel at the stage of its production, the use of expanded clay fraction up to 10 mm, and fiber reinforcement by polypropylene fiber. In conclusion, it is stated that the use of expanded clay concrete products made of structural and heat-insulating concrete can improve the indicators of the functional efficiency of building structures.

Performance evaluation of dispersed basalt fiber on strength of lightweight expanded clay concrete

Performance evaluation of dispersed basalt fiber on strength of lightweight expanded clay concrete

ДИСПЕРСНО–АРМОВАНИЙ ЛИТИЙ КЕРАМЗИТОБЕТОН НА МЕХАНОАКТИВОВАНОМУ ШЛАКОПОРТЛАНДЦЕМЕНТІ

The paper examines the properties of dispersed-reinforced cast expanded clay concrete on mechanically activated slag Portland cement with the addition of Super-PC polycarboxylate superplasticizer. Experimental studies have established the possibility of obtaining lightweight concrete based on high-mobility lightweight concrete mixtures with a diameter of a cone of at least 50 cm. It has been experimentally confirmed that the hydrophobization of expanded clay gravel helps to increase the spreading of the cone of the concrete mixture, and also increases the viability of the concrete mixture. The expediency of mechanical activation of slag Portland cement in the presence of Super-PC to obtain light concrete with increased characteristics in terms of frost resistance, abrasion and impact strength is shown. The results of research are presented, which indicate that the introduction of basalt fiber into slag Portland cement together with the mechanical activation of the binder allows to reduce the abrasion of concrete from 0.44 to 0.13 g/cm2, as well as to increase the impact strength of concrete by almost 2 times (compared to with control). The proposed complex of recipe-technological influences allows to ensure frost resistance of concrete not less than 350 cycles of alternating freezing and thawing. It was established that the mechanical activation of the binder causes an increase in the strength of concrete at the age of 3 days from 11.3 to 16.2 MPa, that is, by more than 40% compared to the control. The introduction of basalt fiber in the amount of 1% of the mass of the binder ensures an increase in the strength of concrete by 10-15%. The joint effect on slag Portland cement of mechanical activation, additives of poly-carboxylate Super-PC and basalt fiber causes an increase in the strength of concrete at the age of 28 days (compared to the control) from 11.3 to 29.5 MPa, i.e. more than 2.5 times. In general, the combined use of the listed recipe-technological factors ensures an increase in the main physical and mechanical characteristics of lightweight concrete.

Radiation attenuation ability of bentonite clay enriched with eggshell as recyclable waste for a physical rradiation barrier

Living cells are protected from ionizing radiation by shielding materials such as lead and concrete. This research aims to develop eco-friendly, low-cost, and non-toxic materials for use as physical radiation shielding materials. Bentonite clay and eggshell powder (ESP) were chosen for this study to develop alternative materials that can replace the usage of ordinary concrete in the construction of a physical barrier for radiation shielding. Various samples of bentonite clay concretes were prepared by adding 0%, 25%, 50%, 75%, and 100% of ESP. Four layers consisting of bismuth oxide (Bi2O3), tungsten oxide (WO3), bismuth oxide with graphene oxide (Bi2O3 + GO), and tungsten oxide with graphene oxide (WO3 + GO), loaded in epoxy matrix composites, were developed and added for enhancing concrete blocks' ability to absorb X-rays. PTW Diados with an ionization chamber was used to measure the absorbed dose of the prepared samples at X-ray tube energies of 60, 80, 100, and 120 kVp. The addition of ESP to Bentonite clay samples improved the attenuation ability of clay. The percentage of 75% ESP added to Bentonite clay is the optimum amount to achieve the best attenuation. Also, the addition of the layers significantly enhanced the block samples' ability to attenuate X-rays. On the other hand, the effectiveness of graphene oxide (GO) in increasing the X-ray attenuation capacity of WO3 and Bi2O3 depended on the applied kVp values (adding GO to Bi2O3 resulted in an improvement in Bi2O3 attenuation capacity at 60 and 80 kVp only). As a result, Bentonite clay blocks enriched with ESP and reinforced with Bi2O3, WO3, Bi2O3 +GO or WO3+GO layers are recommended as an effective radiation shielding materials.

Mechanical characteristics of hardened basalt fiber expanded clay concrete cylinders

Concrete is a universal construction material, and it is one of the most widely used materials in civil engineering. Concrete is strong in compression but weak in tension, therefore exhibiting brittle material characteristics. Lightweight concrete (LWC) has a considerably lower density compared to normal concrete and this is associated with its brittle nature, thus affecting the strength, ductility, and durability of lightweight concrete. To improve these shortcomings and proffer solutions, this paper investigates the effects of dispersed chopped basalt fiber (BF) incorporation in concrete and basalt fiber reinforced polymer (BFRP) mesh for concrete confinement. An experimental investigation was conducted to determine the strength and toughness of BF reinforced lightweight expanded clay concrete (LWECC). This experiment was performed with eighteen (18) specimens of LWECC cylindrical column with 1.6% chopped BF mixed with lightweight ECC. To verify this experiment, three-dimensional finite element models (FEM) were created based on the experimental loading and accounted for tested material properties. A close agreement was achieved between the test and finite element analysis results, split tensile strength, compressive strength, and stress-strain relationship of cylindrical basalt fiber concrete was developed. The results proved the best porosity index, compressive strength and modulus of elasticity when expanded clay concrete was reinforced with BF and confined in BFRP mesh.

ИССЛЕДОВАНИЕ ФИЗИКО-МЕХАНИЧЕСКИХ СВОЙСТВ КРУПНОПОРИСТОГО КЕРАМЗИТОБЕТОНА ДЛЯ ТРЕХСЛОЙНОГО 3D-АДДИТИВНОГО СТРОИТЕЛЬСТВА

The article considers the solution of the urgent problem of the development of 3D additive technologies in Russia by creating a new model of the forming device and the development of composite materials. The purpose of this work is to study the physical, technological and thermal properties of coarse-pored expanded clay concrete. The required characteristics are determined by standard methods and requirements of regulatory documents, including modern physico-chemical methods of analysis and a wide range of modern and original research methods corresponding to modern scientific knowledge. Results. Compositions of coarse-porous expanded clay concrete with compressive strength up to 9.2 MPa, water absorption up to 25% by weight and shrinkage deformations in the range of 0.1...0.3 mm/m were obtained. To simulate the behavior of the studied systems, a two-factor three-level experiment was conducted for each type of mixture of coarse-pored expanded clay concrete, which allowed us to obtain regression equations characterizing the relationship of variable parameters with certain properties of the system. It was revealed that the value of the average density is most affected by the specific consumption of the binder. While the strength depends most on the I/O ratio. Moreover, in this case, the amount of water is less related to the porosity of the cement stone itself, and more to the consistency and stickiness of the resulting glue, its ability to evenly cover the filler particles. It is established that rationally selected compositions of structural and thermal insulation KPKB for the internal filling of a three-layer "printed" wall, homologation and thermal insulation will ensure the formation of the required technical and operational indicators.

COMPRESSIVE CYLINDER STRENGTH AND DEFORMABILITY OF EXPANDED CLAY FIBER-REINFORCED CONCRETE WITH POLYPROPYLENE FIBER

This article presents the experimental studies results of the reinforcement effect with polypropylene fiber (0.5 %, 1 %, and 1.5 %) on the strength (compressive cylinder strength) and deformation (compressive strain) characteristics for expanded clay concrete. The most effective fiber percentage is the content of 1.5 % by weight of the cement mass, based on obtained experimental results. An increase in the compressive cylinder strength (up to 13 %), a significant increase in the value of ultimate compressive strain in concrete (corresponding to the peak stress) of the stress-strain diagram (up to 50 %), and the plastic failure of expanded clay fiber-reinforced concrete is noted.

Investigation of the effect of electric heating of expanded clay concrete mixture on the structure and properties of lightweight expanded clay concrete exposed to high temperatures

Objective. The aim of the study is to study the effect of preliminary electrical heating of the concrete mixture on the structure and properties of heat-resistant expanded clay concrete on a composite binder before drying at a temperature of 105°C. Method. It is based on domestic and foreign experience in studying the effect of preliminary electrical heating on the properties and structure of various concretes, including heat-resistant ones. Result. A laboratory stand for preliminary electrical heating of mixtures has been developed and tested. The influence of preliminary electric heating on the process of self-steaming of heat-resistant expanded clay concrete has been studied. A mode of preliminary electric heating of a heat-resistant expanded clay concrete mixture in time has been developed. Stress dependences are obtained due to the difference in the temperature coefficients of linear expansion of coarse and fine aggregates and the mortar part on the heating temperature, as well as the dependences of the ultimate strength of expanded clay concrete on the heating temperature of the expanded clay concrete mixture under various modes of preheating with a composite binder with a ratio of components: Portland cement 70%, mineral additive 30%. Conclusion. Based on the results obtained and the analysis of the studies carried out in the field of preliminary electrical heating of concrete mixtures, it can be concluded that the preliminary electrical heating of a mixture for heatresistant concrete with expanded clay filler based on an activated composite binder will make it possible to obtain concrete with higher physico-thermal and operational characteristics, as well as to reduce the technological process of manufacturing heat-resistant products, the drying period and bringing the thermal unit to the operating mode.

LLC «Vinzili Expanded Clay Gravel Plant» (Tyumen Region). Building Materials Made of Expanded Clay and Expanded Clay Concrete for Civil and Industrial Construction “From The Foundation to the Roof”

LLC «Vinzili Expanded Clay Gravel Plant» (Tyumen Region). Building Materials Made of Expanded Clay and Expanded Clay Concrete for Civil and Industrial Construction “From The Foundation to the Roof”

Lightweight and Extra Lightweight Expanded Clay and Expanded Clay Concrete. Analysis of Traditional and Promising Areas of Their Use in Civil and Industrial Construction

Lightweight and Extra Lightweight Expanded Clay and Expanded Clay Concrete. Analysis of Traditional and Promising Areas of Their Use in Civil and Industrial Construction

Expanded Clay and Expanded Clay Concrete in the Construction Complex of the Country

Expanded Clay and Expanded Clay Concrete in the Construction Complex of the Country

Экспериментально-теоретическое обоснование состава материала конструкций на основе бесцементных вяжущих композиций для водохозяйственного строительства

The process of operation of structures (products, silicon alloys,) as a result of natural carbonation, partial decomposition of calcium hydrosilicates occurs with the formation of secondary calcite and polysilic acid gel. The basis of silicon-oxygen anions of low molecular solubility, characterizes the degree of polymerization of the silicon-containing part: for samples from structures of a 2-year operation. This allows us to conclude about the ongoing chemical reactions between the silica component of the volcanic rock and the free Ca (OH)2, which leads to an increase in the volume of the gel-like component and, as a result, the hardening of expanded clay concrete. The research results indicate that the formation of a hardened contact layer on the surface of the expanded clay aggregate as a result of the chemical interaction of Ca (OH) 2 and sulfate ion with the glass phase of the fi ller, as well as the mutual overlap of the fi elds of the contact layers, due to their development and relatively low consumption of the binder material, presupposes the creation of expanded clay concrete structures with high performance.

Influence of protective and decorative coatings based on sol-silicate paints on the moisture regime of external walls of buildings

The object of research is the humidity regime in external enclosing structures coated with paints with different vapor permeability: ash-silicate, silicate, acrylic and silicone. The purpose of the research is to evaluate the effect of a paint-and-varnish coating based on the developed sol-silicate paint on the change in the moisture regime of the wall, depending on the type of construction. Comparison of the effectiveness of the use of various paints and varnishes is carried out. The properties of the developed sol-silicate paint for finishing the walls of buildings are described. The results of calculating the influence of paints and varnishes on the humidity regime in the walls are carried out. To assess the humidity regime, a technique was used based on the determination of the outside air temperature, with a decrease to which condensation begins to fall out in the walls. This technique makes it possible to compare with high accuracy the humidity conditions in various enclosing structures. Comparison of the humidity regime in the walls of various designs is presented: aerated concrete (from blocks of grades D400, D600), brick, expanded clay concrete. In brick and expanded clay enclosing structures, the influence of the type of insulation (mineral wool mats, expanded polystyrene) on the humidity regime in the walls was also assessed. In the course of research, the thickness of the paint layer varied from 0.2 to 0.6 mm. According to the results of the research carried out in the article, it is shown that when using sol-silicate paint in enclosing structures, the temperature of the onset of condensation and the likelihood of condensation are reduced in comparison with acrylic, silicate and silicone paints. Recommendations are given on the choice of the type of facade paint, taking into account the humidity regime inside the fences of various designs.

Ultimate Compressive Strains and Reserves of Bearing Capacity of Short RC Columns with Basalt Fiber

Increasing the bearing capacity of reinforced concrete structures, reducing material consumption, and ensuring quality are critical in modern construction. The article presents an experimental study of the ultimate compressive strains of short fiber basalt reinforced concrete columns and provides recommendations for increasing the bearing capacity using steel reinforcement bars with greater strength. The columns were tested in an upright position using a hydraulic press. Strains were measured with dial indicators and a strain gauge station. It was shown that the addition of 10% coarse basalt fiber increased the ultimate compressibility of concrete on ordinary crushed stone by 19.8%, and expanded clay concrete by 26.1%, which led to the strain hardening of concrete under compression by 9.0% and 12%, respectively. Ultimate compressive strains in fiber-reinforced concrete short columns with combined reinforcement increased 1.42 times in columns on a lightweight aggregate and 1.19 times on heavy aggregate. An increase in the ultimate compressibility of concrete makes it possible to use steel reinforcement with greater strength in compressed elements as the concrete crushing during compression occurs primarily due to the reaching of critical values by tensile stresses in the transverse direction. This makes it possible to manufacture structures with a higher load-bearing capacity and less material consumption. A practical example of the application of the proposed approach is given.

Experimental Study of Elevated Temperature Effects on Properties of Nano Clay and Glass Fiber Concrete

Concrete is mostly use construction material. Concrete is composite material composed of fine and coarse aggregate bonded together with a cement paste that cure over time. Generally concrete is strong in compression and weak in tension. Concrete is brittle material and will crack when we increasing tensile force. Nano clay are nano-size particles of layered mineral silicates. Adding a nano clay is a could fill the original hydration products pores and colloid capillaries increase the cement paste density of concrete. Alkali-resistant glass fiber has a high degree of corrosion resistance in the environment of cement and other alkaline medium. Glass fiber gives high tensile strength. Objective of research is increase mechanical strength of concrete with use of nano clay (NC) and glass fiber (GF). In present study, Concrete grade use is M30.In study 2% of NC is fix replacement of cement and variation of GF is use 0.5%,1%,1.5% as admixture. Temperature effect give 80℃,180℃,300℃for 3 hours. After adding NC and GF check the difference test result like a slump, Compressive, split tensile and flexural strength test. The specimens will be tested on 3,7, and 28 days.

A review of the Effect of Calcination Temperature on the Properties of Calcined Clay Concrete

Naturally occurring clays can produce an amorphous siliceous material possessing pozzolanic properties if is heated at an appropriate temperature. Calcination at the right temperature is crucial since it affects the formation of relevant phases, pozzolanic reactivity, hydration kinetics and consequently, increase the strength and durability of concrete. This paper reviews the effect of calcination temperature on the properties of mortar and concrete corporating calcined clay as partial cement replacement. It is observed that calcination temperatures close to 900°C decrease the specific surface and represent the onset for the structural reorganization of aluminosilicates. Both factors limit the pozzolanic reactivity and can consequently compromise compressive strength. The results show that mortar containing 20% calcined clay obtained compressive strength of 63MPa when calcined at 800oC, surpassing the reference cement by about 8MPa.

Expanded clay concrete mixtures and concretes on carbonate sand propertie improvement

Results of researches of properties of expanded clay concrete on carbonate sand, mixtures and concrete, as well as a technique for selecting optimal concrete compositions for monolithic load-bearing and enclosing structures of residential and public buildings and structures are given.

Researching of properties of expanded clay concrete on cement-ash binder.

Ukraine is a state with a powerful industrial base,the waste of which is ash. The use of ash as a binder for the production of expanded clay concrete solves the problem of its disposal. Studies of expanded clay concrete on carbonates and and cement-ash binder were carried out.The research results showed that it is possible to manufacture building structures from this material, including load-bearing ones. Experiments have confirmed the effectiveness of using a cement-ash binder [Vilkov, 1984]. The article provides recommendations on the technology of production of expanded clay concrete mixture and determination of optimal composition. Were made and tested samples of expanded clay concrete on a cement-ash binder with varying degrees of reinforcement with dimensions of 100x150x1200mm. The bearing capacity, crack resistance and deformability of expanded clay concrete were determined by testing on hydraulic press. The compressive strength of the studied expanded clay concrete was tested by loading samples with dimensions of 10x10x10cm and 10x10x40cm. The perspectives of using expanded clay concrete on a cement- ash binder are analyzed.
 Keywords: expanded clay concrete, industrial waste, binding material, ash, carbonate send, strength, deflection, deformation, building construction.

STRENGTH OF ANCHORING OF BLOCKED SPIRAL ANCHOR LINKS IN MASONRY

. The results of experimental studies of the tensile load resistance of the anchor fastening of Sure Twist stainless steel spiral anchors, established by driving into the body of masonry products made of aerated concrete, expanded clay concrete, dense silicate concrete, porous ceramic, are presented. Repair spiral-shaped bonds are used to connect the cladding with the inner layer when reinforcing and repairing multilayer external walls, when repairing brickwork in the crack formation zone, restoring metal bonds lost due to corrosion, and also arranging vertical expansion joints in the building cladding. The method of installing spiral ties by driving masonry products into the body significantly simplifies and cheapens repair work. As a result of the studies, the dependences “load-displacement of the anchor connection” were established, on the basis of which the characteristic and calculated values ​​of the pulling load and the adhesion strength of the bonds with masonry products manufactured in the Republic of Belarus were obtained. The characteristic values ​​of the pulling load and the adhesion strength of bonds with masonry products were determined in accordance with the criteria established in the standard EN 846-6 and FCS – 44416204-09. When determining the calculated values ​​of the tensile load and the adhesion strength of the bonds, the values ​​of the characteristics of the characteristics of the material properties gM, according to TKP 45-5.03-308, depending on the class of work performance control, were assumed to be 2.0-2.5, and the value of the reliability coefficient for the material according to the breaking load m, according to the FCS – 44416204-09 equal to 3,0.      

Basalt fiber reinforced expanded clay concrete for building structures

Basalt fiber reinforced expanded clay concrete for building structures