Clay Concrete Research Articles

Polypropylene Fiber as a Factor of Reduction of the Total Shrinkage Strain of Expanded Clay Concrete

Statement of the problem. The article presents the development features of the total shrinkage strain of expanded clay concrete, expanded clay fiber-reinforced concrete, expanded clay steel-reinforced concrete, and expanded clay fiber-steel-reinforced concrete. According to the analytical review, the shrinkage strain decrease as a result of the fibers adding was noted by the researchers without analyzing the reason for the phenomenon. Therefore the purpose of the study is to establish the reason for the decrease of the shrinkage strain of expanded clay concrete with the addition of polypropylene fibers. Results. It has been confirmed that the polypropylene fiber addition reduces the total shrinkage strain of expanded clay concrete by 29—34 % on the 120th day with the volume content of fibers of 0.36 %. Empirical dependences of deformations compatibility for expanded clay fiber-reinforced concrete and expanded clay fiber-steel-reinforced concrete are set forth. Conclusions. It has been experimentally established that fiber is a significant factor on the first days of the concrete mixture hardening, when the elastic modulus of the fiber is greater than or equal to the elastic modulus of the cement stone. Fibers act as a bond and affect the redistribution of shrinkage stresses within the composite, thus reducing the values of the total shrinkage strain.

Multilayer prefabrication in practice

Pre-cast reinforced concrete walls manufacturing is still associated in Poland with large-panel construction, all the advantages of which have been crossed out by technological imperfection, terrible workmanship and boring, repetitive architecture. Meanwhile, modern large-panel prefabrication provides almost unlimited creative possibilities and ensures much better quality than traditional construction. The article describes application of modern multi-layer pre-cast elements made of reinforced concrete and light-weight expanded clay concrete in construction with the incorporation of BIM technology. It presents the advantages of prefabricated construction on specific examples at various scales - from single-family houses to large residential and apartment buildings. It also presents in detail the implementation process from design, through BIM modelling, production and quality control of elements and assembly.

Research and analysis of the influence of recipe and technological factors on the strength of expanded clay concrete on quartz sand

The aim of the work is to study the strength and deformation properties of expanded clay concrete on cement-ash binder and to prove the technical possibility and economic feasibility of its study in structural elements of civil buildings. The five-factor plan B5 was implemented. In the matrix, each of the technological factors changed at three levels (-1; 0; +1), which made it possible to obtain quadratic mathematical models of output parameters - the bulk mass of concrete, cubic and prismatic strength of the expanded clay concrete at the age of 1 (a.s), 28, 115, 180 and 360 days, when the expanded clay concrete mixture is mobile (the constant draught of the cone is DC= 2...6 сm). Processing of experimental results to identify regularities of influence of studied factors - consumption: cement (x1); lime (х2); fly ash (х3); expanded clay gravel (х4); quartz sand (x5) on water consumption of ceramic and concrete mixtures – B, volume of inter-grain voids Vn, the density of the ceramic concrete mixture – ρo and the density of the expanded clay concrete ρ allowed to obtain with 95% reliability quadratic regression equations, taking into account only significant regression coefficients. Based on the results of experimental studies with 95% reliability quadratic regression equations of cubic and prismatic strength in the age of 1 (a.s), 28, 180* and 360* days are obtained, expanded clay concrete on CLF-binder and quartz sand with only significant regression factors. The paper examines and analyzes the influence of recipe and technological factors on the strength of expanded clay concrete on quartz sand. The invention makes it possible to use the dependence of a cubic and prism strength expanded clay concrete on quartz sand using a large component binder with a further prospect of saving cement and fillers.

Dematerialization of Concrete: Meta-Analysis of Lightweight Expanded Clay Concrete for Compressive Strength

The construction industry is responsible for a significant share of global material consumption, including natural resources. Therefore, the United Nations Sustainable Development Goal 12.2 on sustainable management and efficient use of natural resources cannot be achieved without significant advances and contributions from the construction sector. Furthermore, various materials used by the construction industry contribute to the development and expansion of the LEED (Leadership in Energy and Environmental Design) system. LECA (Light Expanded Clay Aggregate) is one such material that enhances LEED performance through its key benefits, including lightness, thermal insulation, sound insulation, and fire resistance. One of the most effective methods for reducing the weight of concrete is the incorporation of lightweight aggregates, and the advantages of LECA include lessening loads and enabling reduced cross-sections, directly improving the sustainability of the built environment via reduced materials consumption. This study aims to develop a prediction model for the compressive strength of LECA-incorporated concrete through a meta-analysis. More than 140 data points were compiled through literature via 15 separate studies, and results were analyzed to conduct the meta-analysis. Moreover, an experimental program was carried out to verify the model and evaluate its accuracy in predicting compressive strength. Results from the developed model and the experimental program were in accordance with concrete having lower compressive strengths compared to those at high strength values. Likewise, more accurate results were obtained for concrete mixes that have w/b ratios of 0.5 or higher. Concrete mixes that have higher amounts of LECA by volume of concrete yielded more accurate results when using the prediction model. A sensitivity analysis was carried out to quantify the impact of several parameters on the compressive strength of LECA concrete.

Performance of cementitious systems containing calcined clay in a chloride-rich environment: a review by TC-282 CCL

In this review by TC- 282 CCL, a comprehensive examination of various facets of chloride ingress in calcined clay-based concrete in aggressive chloride-rich environments is presented due to its significance in making reinforced concrete structures susceptible to chloride-induced corrosion damages. The review presents a summary of available literature focusing on materials characteristics influencing the chloride resistance of calcined clay-based concrete, such as different clay purity, kaolinite content and other clay minerals, underscoring the significance of pore refinement, pore solution composition, and chloride binding mechanisms. Further, the studies dealing with the performance at the concrete scale, with a particular emphasis on transport properties, curing methods, and mix design, are highlighted. Benchmarking calcined clay mixes with fly ash or slag-based concrete mixes that are widely used in aggressive chloride conditions instead of OPC is recommended. Such comparison could extend the usage of calcined clay as a performance-enhancing mineral admixture in the form of calcined clay or LC2 (limestone-calcined clay). The chloride diffusion coefficient in calcined clay concrete is reported to be significantly lower (about 5–10 times in most literature available so far) compared to OPC, and even lower compared to fly ash and slag-based concrete at early curing ages reported across recent literature made with different types of cements and concrete mixes. Limited studies dealing with reinforcement corrosion point out that calcined clay delays corrosion initiation and reduces corrosion rates despite the reduction in critical chloride threshold. Most of these results on corrosion performance are mainly from laboratory studies and warrant field evaluation in future. Finally, two case studies demonstrating the application of calcined clay-based concrete in real-world marine exposure conditions are discussed to showcase the promising potential of employing low-purity calcined clay-based concrete for reducing carbon footprint and improving durability performance in chloride exposure.

MATERIAL AND ARCHITECTURAL FORM: MODERN POSSIBILITIES OF RELATIONSHIP

The reliance of architectural designs on the possibilities of material support is one of the challenges of construction. The expansion of these relationships contributes to the development of modern technologies and the search for new materials. The goal is to highlight the relationship between building materials and architectural form and to study the prospects of the influence of modern building materials on the architectural image of a building object in the future. If, until the beginning of the last century, statics dominated the architectural form, then the development of science contributed to the emergence of building materials resistant to bending and stretching and dynamic architectural structures. In general, all building materials have undergone an evolution from classic to innovative with the inclusion of additional components and even nanostructures in their composition. Stone and clay are the oldest natural building materials. Stone has long been used for the construction of foundations, walls, stairs, and corridors. At the same time, modern stone architectural forms were transformed into pixelated facades, landscape elements, coatings, and exterior and interior zoning. Clay with various additives is used for the production of clay concrete, fibre concrete, and a clay-stone mixture reinforced with barbed wire. If traditional wooden architecture is characterized by a simple geometry of forms with right angles, then at the modern stage, plastic outlines are created thanks to digital design and the introduction of hydrophobic nanoparticles. Artificial building materials require a lot of energy during production and have a large carbon footprint. At the same time, reinforcing concrete with various types of fibres increases compressive and tensile strength and improves wear and impact resistance. Modified brick with additives has increased moisture resistance, frost resistance and wear resistance. Modern architecture uses the natural properties of brickwork to create a "pixel" surface effect. The modern form of traditional glass - foam glass, is an effective heat-insulating, sound-insulating and structural material. Metal structural, fencing and finishing elements. At the same time, the modern use of metal on facades (foam metals, metal polymers) more effectively emphasizes the texture and peculiarity of the forms. A type of tile with photo modules allows you to produce electricity. Connection of material and architectural forms has deep historical roots. The creation of new materials contributes to the improvement of forms. Modern architectural forms are implemented not only with the use of natural materials, but also innovative ones, including the use of nanotechnology. This makes it possible to endow natural materials with the properties required by the modern construction industry.

Impact of Limestone Calcined Clay Concrete (LC3) in Various Aggressive Soil Environments: A Comprehensive Review

Aggressive soil environments are known for causing deterioration in concrete sub-structure and attacking the concrete of the earth structures by chemical contamination of the soil with fluoride, sulfide, and chloride. The degree of deterioration in the soil can vary from rapid dissolution to minor effects. Many construction materials placed underground are exposed to the aggressive action of the soil. Therefore, studying the impact of soil nature on the deterioration of concrete is crucial to maintaining the safety and efficiency of infrastructures. Recent research states that the conception of limestone calcined clay concrete (LC3) is different from ordinary concrete. Therefore some changes in durability and strength might occur. Hence the present study focuses on the strength and durability aspects, which are of prime importance in almost all concrete structures and permeability. This review stated that LC3, due to their dense microstructure, were chemically resistant in terms of compressive strength, surface scaling, and length change in the aggressive soil environment. These promising results escalate LC3 to be suitable for more reliable concrete earth structures. This paper discusses the properties, optimisation method, environmental impacts, strength, and durability of LC3 and ends with suggestions on subjects on which further research is required.

Improving the thermal properties of lightweight concrete exterior walls

This article is devoted to the development of energy-efficient porous expanded clay concrete for exterior walls. Experimental data confirming the expediency of designing the optimal composition of porous concrete according to the general method of designing the optimal composition of the general theory of artificial building conglomerates (ABC) are presented. The presence of waste ash from thermal power engineering and a complex gas–forming agent based on the polymer K-9 reagent in the concrete provided increased durability, improved humidity and thermal engineering conditions of porous concrete.

Comparative Analysis of Statistical Thickness Models for the Determination of the External Specific Surface and the Surface of the Micropores of Materials: The Case of a Clay Concrete Stabilized Using Sugar Cane Molasses

Comparative Analysis of Statistical Thickness Models for the Determination of the External Specific Surface and the Surface of the Micropores of Materials: The Case of a Clay Concrete Stabilized Using Sugar Cane Molasses

ДРІБНОЗЕРНИСТІ ЗАПОВНЮВАЧІ АСФАЛЬТОБЕТОННИХ СУМІШЕЙ З ПРОДУКТІВ РЕСАЙКЛІНГУ БУДІВЕЛЬНОГО ЛОМУ

The substantiation of the need to develop and implement new resource-saving technologies for the production of construction mixtures using aggregates obtained as a result of complex processing of solid inorganic construction waste is provided. Analytical studies of technogenic waste processing technologies for obtaining building materials have been conducted. The results of the study of the experience of construction scrap processing are presented, with confirmation of the expediency of the fact that the technology of recycling accumulated construction scrap dumps in the territory where the destroyed buildings were located does not require any new specialized measures. The projected volumes of building materials in the composition of residential construction objects with various quantitative parameters of the constituent components of the elements of the fencing structures are presented. Analytical studies have established that the accumulated volumes of construction scrap from the destruction of elements of buildings and structures in the vast majority include the remains of concrete, reinforced concrete, expanded clay concrete, brickwork made of ceramic and silicate products. Experimental series of aggregate samples were made using experimental samples of construction scrap, their granulometric characteristics were determined and physical parameters were investigated. With the use of regulatory and technical literature, the predicted prescription parameters of the concrete mixture using a new variety of aggregates obtained by re-processing of construction scrap were compiled. The presence of reactive substances on the surface of the obtained aggregates was substantiated and the presence of increased physical and mechanical characteristics of the samples with a decrease in the binder content was confirmed. Recipe and technological parameters for the production of wall building materials using the obtained multicomponent building mixtures are proposed. The results of tests of physical and mechanical characteristics of test samples of concrete using aggregates from solid inorganic waste are presented.

SUGGESTIONS FOR CALCULATION OF RELATIVE STRAIN OF THE TOTAL SHRINKAGE OF EXPANDED CLAY CONCRETE

The article provides an analytical review of studies on the shrinkage strain development of expanded clay concrete, based on which it was established that a significant factor is the local raw material base. It means that for each region it is important to accumulate experimental data and correct design models for the analytical determination of the total shrinkage strain. In this regard, the task of the study was to develop suggestions for calculating the relative strain of the total shrinkage of expanded clay concrete, made on the basis of the local raw material base. Predicated on the results of the study and according to the provisions of SP 5.03.01 and Eurocode 2, the improved model for the analytical determination of the values of relative strain of the total shrinkage of structural expanded clay concrete was developed. The proposed model takes into account the value of cement activity as a determining factor of the cement stone strength, and it takes into account the water-cement ratio and the coarse aggregate volume. The proposed design model makes it possible to determine with sufficient accuracy the value of the relative strain of the total shrinkage of expanded clay concrete at the age of 28 to 120 days.

Identifying the influence of expanded clay concrete based on a binder from phosphorus slag on the strength of structures from leaked concrete

The paper presents the results of experimental studies of concrete and compressed reinforced concrete elements from cementless claydite-concrete. An experimental study of reinforced concrete elements with central and eccentric application of forces was carried out to determine their increased sensitivity. The construction material is cementless expanded clay concrete, obtained by a mixture of finely divided granular electrothermophosphorus slag. The tests were carried out on reinforced concrete compressed elements with central and eccentric application of longitudinal force to determine their bearing capacity. According to the test results, the strength and deformation properties of new concrete on a glass-slag binder and the calculation of reinforced concrete structures are checked. The selection of compositions of glass-slag claydite-concrete of various grades has been made. The use of concrete with a clinker-free binder in construction makes it possible to reduce the need for a scarce building material – cement. Studies of the physical and mechanical properties of glass-slag expanded clay concrete grades M50+M150 with a bulk density of 1,000–1,400 kg/m3 were carried out under a short-term static load. At the same time, the strength and deformation properties of glass-slag expanded clay concrete were studied under short-term action of compressive and tensile loads. The use of any new building material must be preceded by a comprehensive study of it – determination of its strength properties, study of concrete in the structure under load, etc. Building codes and regulations are adopted for the standard construction material, the properties of aggregates are not taken into account. Our studies show that the properties of fillers increase the strength properties of the structure when using claydite concrete on a glass-slag binder in reinforced concrete structures

Shear Behavior of Silty Clay–Concrete Interface Based on Large-Scale Direct Shear Test

Shear Behavior of Silty Clay–Concrete Interface Based on Large-Scale Direct Shear Test

ЗАПОВНЮВАЧІ БУДІВЕЛЬНИХ СУМІШЕЙ З ПРОДУКТІВ РЕЦИКЛІНГУ ТВЕРДИХ НЕОРГАНІЧНИХ ВІДХОДІВ

The substantiation of the need to develop and implement new resource-saving technologies for the production of construction mixtures using aggregates obtained as a result of complex processing of solid inorganic construction waste is provided. Analytical studies of technogenic waste processing technologies for obtaining building materials have been conducted. The results of the study of the experience of construction scrap processing are presented, with confirmation of the expediency of the fact that the technology of recycling accumulated construction scrap dumps in the territory where the destroyed buildings were located does not require any new specialized measures. The projected volumes of building materials in the composition of residential construction objects with various quantitative parameters of the constituent components of the elements of the fencing structures are presented. Analytical studies have established that the accumulated volumes of construction scrap from the destruction ofelements of buildings and structures in the vast majority include the remains of concrete, reinforced concrete, expanded clay concrete, brickwork made of ceramic and silicate products. Experimental series of aggregate samples were made using experimental samples of construction scrap, their granulometric characteristics were determined and physical parameters were investigated. With the use of regulatory and technical literature, the predicted prescription parameters of the concrete mixture using a new variety of aggregates obtained by re-processing of construction scrap were compiled. The presence of reactive substances on thesurface of the obtained aggregates was substantiated and the presence of increased physical and mechanical characteristics of the samples with a decrease in the binder content was confirmed. Recipe and technological parameters for the production of wall building materials using the obtained multicomponent building mixtures are proposed. The results of tests of physical and mechanical characteristics of test samples of concrete using aggregates from solid inorganic waste are presented

Chloride Penetration Resistance, Electrical Resistivity, and Compressive Strength of Concrete with Calcined Kaolinite Clay, Fly Ash, and Limestone Powder

This study aims to examine the chloride penetration resistance, chloride binding capacity, electrical resistivity, and compressive strength of multibinder systems, including ordinary portland cement (OPC), calcined kaolinite clay (C), fly ash (F), and limestone powder (L). At all tested ages, the results revealed that calcined kaolinite clay concrete had better chloride penetration resistance and chloride binding ability compared with the control OPC concrete. Moreover, at all tested ages, calcined kaolinite clay concrete had greater compressive strength compared with the control OPC concrete and fly ash concrete. At the curing age of 91 days, improved performance of fly ash concrete was observed. The overall performance of the ternary binder system of cement-fly ash-calcined kaolinite clay surpassed that of the binary binder systems. Among the tested combinations of binders, the ternary binder C30F15 (55% OPC+30% C+15% F) demonstrated the best overall performance. The test results also indicate that fly ash can be beneficially integrated into the cement-calcined kaolinite clay binder system to obtain a ternary binder system, which is better than the ternary binder system of cement, calcined kaolinite clay, and limestone powder, at both tested early and later ages.

Reuse of tire waste in light concrete

Lightweight concrete is characterized by its low density due to the incorporation of lightweight materials such as aggregate clay or lightweight materials in general. In the city of Aracaju there are companies that promote tire reconditioning generating large amount of waste powder. This study aims to study the reuse of tire rubber waste in lightweight aggregate clay concrete. An experimental program for the analysis of these concretes was developed, varying the percentage of 1, 2.5 and 5% of the tire rubber residue in replacement of the natural fine aggregate and replacing 100% of the natural coarse aggregate with expanded clay aggregate(50% C1506 expanded clay aggregateand 50% expanded clay aggregateC2215). The materials (cement, sand, expanded clays and tire rubber residue) were characterized by granulometric analysis tests and unit mass. The hardened concrete was evaluated by mechanical tests of axial compressive strength, modulus of elasticity and tensile strength by diametral compression, physical tests of water absorption and specific mass, as well as scanning electron microscopy image analysis. The use of expanded clay aggregateand 1% of tire rubber residue ensured better mechanical strength, lower water absorption and higher specific mass than mixtures with 2.5 and 5%, reaching values close to the reference concrete, and the residue be an alternative for reuse avoiding disposal.

Comparison of microcrack formation boundaries determined by complex of physical methods with long-term strength of expanded clay concrete under different types of stress state

This work aims to experimentally study the strength and strain of expanded clay concrete during short-term and long-term compression and tension under various loading modes. A technique for testing expanded clay concrete under short-term and long-term compression and tension, including the boundaries of microcrack formation by a complex of physical methods (tensometric, ultrasonic pulsed, and acoustic emission), is given. The results of tests of expanded clay concrete under short-term and long-term monotonic loading under compression and tension and low-cycle loading under compression, as well as the boundaries of microcrack formation by a complex of physical methods, are obtained. The boundaries of microcrack formation are compared with the long-term strength of expanded clay concrete under various types of stressed states. Strain diagrams of expanded clay concrete under axial compression and tension, and "ultrasound transmission speed - stress level" and "number of acoustic pulses - stress level" diagrams are also obtained. Empirical formulas are proposed for determining the boundaries of microcracking in expanded clay concrete and the relationship between the level of long-term strength and the time of staying specimens under load in compression and tension. The results allow the formulation of several proposals and clarifications for normative documents to calculate and design lightweight concrete elements and structures.

Self-Compacting High-Strength Expanded Clay Concrete of B50-B65 Classes - a New Generation of Expanded Clay Concretes for Structures of High-Rise Building

Self-Compacting High-Strength Expanded Clay Concrete of B50-B65 Classes - a New Generation of Expanded Clay Concretes for Structures of High-Rise Building

Creep in expanded clay concrete at different levels of stress under compression and tension

The paper analyzes the results of experimental studies of the creep of light concrete and the influence of various factors on it. A method for determining the boundary of linear creep of expanded clay concrete has been developed. Experimental studies have been carried out to determine the boundary of linear creep. Experimental creep data and the kinetics of the change in the creep measure of expanded clay concrete over time under axial compression at different levels of long–term load (0.2 - 0.7)Rb are obtained. The limiting values of the relative creep deformation and shrinkage of expanded clay concrete are determined. Empirical formulas for determining and describing the relative deformation of the nonlinear creep of expanded clay concrete, measures of the linear creep of expanded clay concrete under axial tension and compression (if there are no direct experimental data), and the nature of the change are proposed λ(t;τ1)═Cbt(t;τ1)/(t;τ1), depending on (t;τ1) according to the linear law at each site, the nature of the influence of previous loading on the strength and modulus of elasticity of concrete, the limit values of the relative creep deformation and shrinkage of expanded clay concrete.

Challenges in the Design of Prefabricated Single-Family Buildings with Expanded Clay Technology - Selected Architectural and Environmental Aspects

The architectural form of buildings is determined by many factors, one of the most important is construction technology. It remains in a close and inseparable relationship with architectural design. Contemporary technologies in construction are constantly subject to improvements, streamlining, changes aimed at increasing all kinds of efficiency (cost, thermal efficiency, labor input, etc.). One of today’s widely discussed determinants of changes in the way buildings are designed and constructed is environmental issue. An awareness of environmental degradation and climate change and their consequences prompts the search for increasingly sustainable solutions. This paper summarizes the research on prefabricated solutions and their implementation, especially in single-family residential architecture. This article presents pre-design, design, and post-design experiences related to planning and realization of single-family houses with prefabricated wall technology made of light expanded clay concrete. The authors implemented comparative qualitative and quantitative research through case studies, the method also uses experiences from their own research by design practice. The advantages and disadvantages of prefabrication in the selected technology are presented. The authors attempt to answer the question of whether the individual architectural design approach is reflected in the relevant environmental considerations, including, first, those related to the mitigation of climate change and adaptation to its consequences, and to what extent the discussed technology fits into the assumptions of climate and environmentally responsible design.