Plaster Composites Research Articles

Development and characterization of new lightweight waste-based plaster composites for building applications

The development of new environmentally friendly construction materials that incorporate waste as an alternative to traditional raw materials is becoming increasingly important and necessary for the construction sector. Gypsum plasters composites are characterised by their versatility and wide range of applications in precast construction due to their excellent technical performance and low cost. This research presents a new material that incorporates EPS waste in solution and recycled rubber aggregates as secondary raw materials, partially replacing traditional plaster material. In this way, partial mass substitutions of up to 12.5 % have been achieved compared to the reference composites without additions. The results show how the incorporation of EPS in solution allows a more homogeneous integration of the residue in the plaster composite matrix. Although it is true that the incorporation of both residues has slightly reduced mechanical resistance to bending and compression, reaching minimum values of 3.71 MPa and 5.08 MPa respectively, the results obtained greatly exceed the minimum values required by current regulations. On the other hand, in the study conducted with prefabricated false ceiling plates, it has been observed that the combined effect of both residues allows for greater resistance to simple bending than traditional composites, with a reduction in bulk density and thermal conductivity of up to 30.1 % and 26.5 %, respectively. Thus, this work presents a viable alternative for the development of new plaster composites that are more sustainable, lightweight and conducive to advancing towards the industrialisation of the construction sector.

Impact of Jet Fires on Steel Structures: Application of Passive Fire Protection Materials

Jet fires are the second most common fire scenario after spill fires. This type of fire is characteristic of gas and gas–oil fires occurring on oil platforms and gas production and processing plants. The consequences of such fires are characterized by high material damage; this is associated with extensive networks of technological communications, since there is a high density of technological facilities and installations in the territory where these fires occur. At such facilities, there is a large number of steel structures, which under the action of high temperature quickly lose their strength and deform. To protect steel structures in the oil and gas industry, fire protection is used, which consists of different types: boards in the form of flat plates, plasters, and epoxy paints. This paper compares three types of fire protection materials for steel structures under jet fire: board fireproofing, plaster composition, and epoxy coating. When comparing the efficiency in jet fire, cement boards were found to be the best. However, despite the better fire protection efficiency, their low application is expected due to their massiveness and the high cost of such protection and the difficulty of installation. Nevertheless, the development of fire depends on the place of its origin, the size of the initial fire zone, and the stability and massiveness of the metal elements of the vessel structure or the structure of the boards on which the equipment can be placed. Therefore, it is necessary to take these factors into account when selecting fire protection and to apply it depending on the required fire resistance limits of structures, which should be determined depending on the fire development scenarios.

Recovering Low-Density Polyethylene Waste for Gypsum Board Production: A Mechanical and Hygrothermal Study.

In recent decades, plastic waste management has become one of the main environmental challenges for today's society. The excessive consumption of so-called single-use plastics causes continuous damage to ecosystems, and it is necessary to find alternatives to recycle these products. In this work, a mechanical and hygrothermal characterisation of novel plaster composites incorporating LDPE waste in their interior was carried out. Thus, prefabricated plasterboards have been designed with a partial replacement of the original raw material with recycled LDPE in percentages of 5-10-15% by volume. The results show how these new composites exceeded the 0.18 kN minimum breaking load in panels in all cases, while decreases in density and thermal conductivity of up to 15% and 21%, respectively, were obtained. In addition, an increase of 3.8%in thermal resistance was obtained by incorporating these new gypsum boards in lightweight façade walls through simulations. In this way, a new pathway was explored for the recovery of these wastes and their subsequent application in the construction sector.

Investigating the characteristics and thermal performance of plaster composites enhanced with paddy husk for sustainable Residential construction

This study is a big step forward in the field of thermal insulation, establishing rice husk as a legitimate and environmentally acceptable alternative in composite materials. The study focuses on the incorporation of paddy husk, a natural fibre, into plaster matrices to improve thermal insulation. By conducting a wide range of experimental analyses, such as thermophysical tests and physicochemical evaluations, this study reveals the significant influence of paddy husk on plaster formulations. The research shows that incorporating paddy husk leads to significant enhancements in thermal insulation properties, resulting in a noticeable decrease in bulk density and a substantial reduction in thermal conductivity. With a bulk density of 1244.2 kg/m³ for pure plaster, the samples with 20.0 % rice husk show a decreased density of 1055.4 kg/m³, indicating promise for lightweight but strong construction elements. In addition, there is a significant decrease in thermal conductivity, with values dropping from 0.94 W/mK for pure plaster to 0.67 W/mK for samples containing 20.0 % paddy husk, demonstrating excellent insulating properties. The promising result prospects of employing paddy husk to enhance both thermal performance and sustainability in building materials. This investigation constitutes a notable stride forward in thermal insulation research, affirming paddy husk as a feasible and ecologically sound alternative in composite materials.

INCREASING THE WATER RESISTANCE OF THE PLASTER MIXTURE BASED ON GYPSUM-CONTAINING BINDER

The article considers the prospects of using gypsum-based composite materials for repairing damaged walls of limestone-shell rock buildings. Repairing damaged shell rock structures with cement compositions intensifies destructive processes; the use of lime-sand mixtures for repair work on building facades is problematic due to their prolonged hardening. The article substantiates the use of gypsum as the basis of the repair composition. The use of gypsum composites for exterior works requires a significant increase in their water resistance. A plaster mixture based on an ash-cement binder with an addition of lime is proposed; a series of samples with different component contents were made in the planned experiment. Their water resistance was studied using two criteria: the conventional softening coefficient (Кр) and the new one - the water resistance index (Iw); a comparison of these criteria was performed. The significant dependence of these criteria on the measurement conditions, which are not currently standardized, is established. Mathematical models of water resistance characteristics have been built, with the help of which the influence of the content of components on the resistance of the plaster composition to water has been analyzed. To further improve the water resistance of the mixture, a hydrophobizing additive was selected in terms of surface wetting and water absorption. Further research is aimed at optimizing the repair composition using plasticizing, hydrophobizing, and adhesive additives.

Effect of Wall Thickness on Properties of Multilayer Composite Plaster Mold for Investment Casting

Effect of Wall Thickness on Properties of Multilayer Composite Plaster Mold for Investment Casting

Research of the Component Composition of Drying Renovation Brick Crumb Plaster for Restoration of Architectural Monuments

The article presents the results of analytical studies to establish the authentic component composition of the brick crumb plaster, which was used to furnish architectural monuments of the 10th – 12th centuries. In laboratory conditions, a number of experimental studies aimed at the production of brick crumb plaster according to the historical recipe were performed. However, a number of requirements were set for such plaster, according to which it must meet European and domestic requirements for drying renovation plasters. The peculiarity of such plasters is low compressive strength (1.5 – 5.0MPa), high porosity (>45 %) and a low coefficient of resistance to water vapour diffusion (12), which allows drying overmoistened walls and at the same time extracting salts from them and accumulating them in the pores of their volume. In the process of experimental research, the historical recipe of the plaster was slightly modified, which made it possible to obtain a plaster with the specified parameters. The performance of plastering works with a scientifically based recipe of brick crumb renovation plaster on an architectural monument in the city of Chernihiv gave a positive result with a decrease in salinity and humidity of the walls.

Development and characterization of advanced paraffin plaster composite for building energy storage

Thermal energy storage via phase change materials (PCM) is currently a promising solution for minimizing energy consumption and ensuring thermal comfort in buildings. PCM composites enhance energy efficiency by shifting peak energy loads while maintaining a comfortable indoor temperature. This work aims to develop a novel highly stable form of PCM-based composite and assess its performance in plaster. The composite prepared consists of paraffin (RT27) loaded into expanded perlite (EP). The obtained composite was coated with waterproof SikaLatex adherent (SL). Paraffin loading rate reached 70 % by vacuum impregnation. Composite thermal conductivity was enhanced by aluminum (AL). Compared to other PCM plaster boards, the paraffin coated composite amount reached a greater value of 50 wt% in plaster without friability. Thermal conductivity of plaster containing 50 wt% of RT27/EP/SL/Al composite was 0.56 ± 0.02 W/m.K. Temperature and phase change enthalpy measurements were carried out by Differential Scanning Calorimetry (DSC) analysis. The results revealed that prepared composites stored 107.46 ± 1.89 kJ/kg and 93.77 ± 1.65 kJ/kg respectively without and with Aluminum. These composites were thermally stable even after undergoing multiple heating and cooling cycles. Good chemical compatibility between composite components was shown by Fourier-Transform Infrared Spectroscopy (FTIR) analysis. The resulting plaster composite is a stable, leak-proof, low-cost material with high thermal energy storage (TES) efficiency in buildings.

РЕОЛОГИЧЕСКИЕ СВОЙСТВА ИЗВЕСТКОВЫХ СОСТАВОВ С ДОБАВКАМИ ПОЛИСАХАРИДОВ

Lime compositions with polysaccharide additives are being studied. The results are aimed at creating a new lime plaster composition with improved performance properties. Materials and methods. Standard methods for studying rheological and technological properties were used. Results. The influence of polysaccharides on changes in the rheological properties of lime compositions has been established. It has been established that the introduction of a polysaccharide additive (hydroxyethylcellulose) helps to accelerate the development of plastic strength. The results of infrared spectroscopy indicate a higher content of calcite in the sample with the addition of polysaccharide. The absence of chemical interaction between lime and polysaccharides has been established. Conclusions. The introduction of polysaccharide additives promotes the formation of a structure that improves the performance properties of the lime composite.

ОЦЕНКА ПРОЧНОСТИ ОБРАЗЦОВ ИЗ ПЕРЛИТОЦЕМЕНТНОЙ СУХОЙ СТРОИТЕЛЬНОЙ СМЕСИ

The article presents an analysis of the production and application of dry mixes in construction. Today it is already impossible to imagine both new construction and reconstruction or repair of buildings without the use of modified dry mixes. This increases the manufacturability of con-struction processes, reduces their cost and energy intensity of production. The composition of warm plaster has been developed and the strength of samples from perlite cement dry construc-tion mix has been evaluated

Super adsorbent bio-polymer additive to improve hygroscopic and acoustic properties of a conventional lime plaster

The paper introduces a new lime plaster composition, with a Super Bio-Polymeric Adsorbent (SABP), for interior applications to improve hygrothermal and acoustic comfort. Alginate SABP is added to a conventional lime plaster to improve hygroscopic and acoustic performance. The hygrothermal and acoustic properties of the modified plaster are compared with the ones of the original plaster with a preliminary moisture uptake test, the evaluation of the sorption isotherm, the moisture buffering value (MBV), and the acoustic absorption. The results show a significant increase in the equilibrium moisture contents and the MBV (from 0.7 to 6.2 g/(m2⋅%RH)). At the same time, the sound absorption coefficient is slightly improved, increasing 0.1-0.2 at frequencies higher than 500 Hz compared to the reference conventional lime plaster. The paper describes the material characterization: the sorption isotherm and the MBV are obtained using a dynamic vapor sorption (DVS) analyzer. The acoustic absorption is measured using the impedance tube method.

Properties and Fracture Mechanism of Composite Plaster Mold Covered with Multiple Adhesion Layer for Investment Casting

Properties and Fracture Mechanism of Composite Plaster Mold Covered with Multiple Adhesion Layer for Investment Casting

Study of the hygroscopic properties of environmentally friendly lightened composites through waste recovery

Gypsum-plaster is becoming an ideal binder in the valorisation and recovery of waste for designing more sustainable composites. Nevetheless, the main limitation of plaster lies in its susceptibility to the action of water. In this research, a complete study of the hygroscopic properties of a new material has been carried out, in which plaster material has been partially substituted in mass by dissolved expanded polystyrene waste in percentages of 8.8% to 26.5%. Additionally, fibres from end-of-life tyres have been incorporated at 1.2% by mass to improve the strength and durability of the compounds, achieving a total reduction of up to 28% of the original raw materials. The experimental campaign delves into the water performance of this new plaster composites through mercury porosimetry tests, water absorption by capillarity, total water absorption, water vapour permeability, Karsten Tube penetration, water-stove cycles, as well as the analysis of images obtained by scanning electron microscopy. The main results obtained show a reduction of 97.8% in surface water absorption, as well as a decrease of up to 17.44% in water vapour permeability compared to traditional plaster. Moreover, the developed materials exhibit good mechanical behaviour after undergoing several accelerated ageing cycles. This work highlights the potential of the new plaster composites designed to produce a more sustainable alternative to commercial prefabricated boards and panels, especially suitable for use in interior rooms where high resistance to the action of water is required.

Material and Technical Analysis as a Support for Art-Historical Characterization of Selected Mural Paintings in Austria around 1400

Several medieval mural cycles in Austria were studied from the material and technical point of view, aiming to confirm (or reject) the art-historical hypothesis of their stylistic and workshop connection. These paintings can be found in the churches of Rust (“Fischerkirche”), Marz (Virgin’s Coronation parish church), Kobenz (St. Ruprecht parish church), Ofenbach (St. Veid parish church), and St. Johann am Steinfelde (St. John parish church). They were carried out around 1400 in the International Gothic style. Their workshop connections based on the style are doubtful, therefore, a material and technical study was carried out. Results showed different plaster composition, similar pigment palette, and diverse painting procedures. The murals in Marz, St. Johann, and the older register in Rust reveal important similarities such as plaster composition, predominant a fresco painting technique, the use of natural inorganic pigments, as well as many aspects of the painting procedure and modeling. On the contrary, those in Kobenz, Ofenbach, and the younger register in Rust differ considerably. The second group reveals lower quality in plaster composition, larger a secco parts, addition of synthetic pigments (Kobenz), and a rougher color modeling, indicating less skilled artists. The lower quality also results in a worse conservation state of these murals. The obtained results confirm the same workshop, but different artists in the first group, while in the second group no clear workshop/artist connection could be established.

Gypsum plaster composites reinforced with tropical fibre bundles extracted from Rhecktophyllum camerunense and Ananas comosus plants: Microstructure and mechanical performance

Tropical fibre bundles of Rhecktophyllum camerunense (RC) and Ananas comosus (AC) extracted from the equatorial region of Cameroon were characterised and used as fibrous reinforcement of gypsum plaster composites. A better understanding of the structural and mechanical properties of these fibre bundles is crucial to use them as biosourced fibrous reinforcement of construction materials. Scanning Electron Microscope (SEM) micrographs revealed the presence of RC fibre bundles with or without open central channels. Two types of AC fibre bundles were also observed: fibrovascular and mesophylian fibre bundles. The inner porosity of RC and AC fibre bundles depended on the type of fibre bundle. Tensile tests revealed that the mechanical properties of individual fibre bundles were quite dispersed. This dispersion was quantified using Weibull distributions. The average values for the Young's modulus, tensile strength and elongation at break of AC (resp. RC) fibre bundles were 12.2 GPa, 487 MPa and 3.2% (resp. 5.2 GPa, 268 MPa and 21.6%), respectively. The dispersion was found to be correlated to the geometry of the cross-sections of the fibre bundle, the gauge length, and the plant type. Gypsum plaster composites were then prepared by casting/evaporation using a water/plaster mixing ratio of 0.8 and a fibre bundle volume content of 1%. The composites were characterised using bending and indentation tests. It was shown that the studied fibre bundles induced a noticeable increase of the flexural stiffness, the stress at break and toughness of gypsum composites, although lower than that given by a similar volume fraction of glass fibre bundles. Increasing the aspect ratio of plant-based fibre bundles would also lead to higher flexural mechanical performance of gypsum plaster composites.

Thermal and mechanical evaluation of natural fibers reinforced gypsum plaster composite

Many problems such as the increase in the world population, global drought, and greenhouse gases have caused materials used in industries to be reconsidered. This is how the concept of green composite material emerged. Using natural fibers to obtain such materials is important in terms of sustainability. This study is aimed to use hemp fiber and banana fiber as natural fiber additives in the gypsum composite to produce green bio-composite. Natural fibers are chemically modified with 5% NaOH solution. In this way, a good fiber/matrix interface interaction is provided. The composite hardness test result of 5 wt% HB fiber added sample is obtained as 50.4. Compared to the control plaster sample test result, which is 53.6, a slight decrease can be seen. However, it is observed that the fibers held the structure together and sopped the crack propagation. The increase in the porous structure with fiber addition caused a decrease in the thermal conductivity of the composite. Comparing thermal conductivity result of 5 wt% HB fiber reinforced gypsum composite (0.131 W⸳mK-1) with respect to pure gypsum result (0.237 W⸳mK-1), it gave a promising result as an insulation material.

FIRE BEHAVIOR OF PLASTER COMPOSITE MATERIALS LIGHTENED WITH PERLITE AND SUPER-ABSORBENT POLYMERS

The effects of fire on construction materials and systems can affect buildings in many different aspects, ranging from minor surface damage to severe effects that can affect their dimensional stability and load-bearing capacity. The aim of this research is to characterise the effects of fire on a new plaster material specially designed for the manufacture of prefabricated elements. This plaster composite is made by incorporating superabsorbent polymers and perlite, which reduces its density and thermal conductivity. In the study, real direct fire exposure tests were carried out, in order to subsequently carry out a mechanical characterisation of the new plaster composites and check the effects that a fire would have on them. The incorporation of sodium polyacrylate and potassium polyacrylate as superabsorbent polymers together with the addition of perlite has been shown to improve the fire resistance of the plaster composites. Keywords: fire behavior, lightweight plaster, perlite, superabsorbent polymers.

Characterization and under Water Action Behaviour of a New Plaster-Based Lightened Composites for Precast.

Plaster is a construction material widely used for the production of prefabricated parts in building construction due to its high capacity for hygrothermal regulation, its good mechanical performance, and its fireproof nature, among other factors. Its historical use has been linked to ornamental elements, although more recent research is oriented towards the industrialisation of plaster composites and the design of prefabricated parts for false ceilings and interior partitions. In this work, the behaviour against water of four new plaster-based composite materials is studied, using additions of two types of super absorbent polymers (sodium polyacrylate and potassium polyacrylate) and a lightening material (vermiculite) in their manufacturing process. In addition, the transmission of water vapour through the samples was studied together with the water absorption capacity of the samples in order to check the suitability of the use of plaster-based materials exposed to these environments. The results of this study show that composites with the addition of super absorbent polymers as well as vermiculite significantly improve their water performance compared to traditional materials up to 7.3% water absorption with a minimal (13%) reduction in mechanical strength compared to current materials with similar additions. In this sense, a plaster material is obtained with wide possibilities of application in the construction sector that favours the development of sustainable and quality buildings, in line with Goal 9 for Sustainable Development included in the 2030 Agenda.

РОМАНЦЕМЕНТ – МАТЕРИАЛ СТРОИТЕЛЬНОГО НАСЛЕДИЯ

Statement of the problem. Many cultural heritage buildings of 17th–18th centuries in Russia and abroad require reconstruction not by modern systems such as ventilated facade or “wet facade”, but by authentic materials based on roman concrete. The authenticity lies in its unique structure, which is obtained after the drying of the plaster composition based on roman concrete. This material has a number of advantages: it permits the movement of steam and moisture, allowing the façade to breathe and preventing the growth of fungi and mold; it is lighter than plaster mixes based on Portland cement; and the texture is aesthetically pleasing. Compositions based on roman concrete have demonstrated their applicability in facade reconstruction, since it perfectly retains the old plaster, increasing service life. The purpose of this article is to give an overview of the production and use of roman concrete in the 17th and 18th centuries for finishing facades and stucco. Our task is to review and analyze the advantages and disadvantages of roman concrete and the experience of its production and use, and justify the prospects of researching and improving its composition and properties. Results. We define the necessary performance properties of roman concrete for the reconstruction and resto-ration of facades. Conclusions. Roman concrete is one of the few materials with a composition and structure compatible with architectural monuments that is suitable for restoration.

Dissolved recycled expanded polystyrene as partial replacement in plaster composites

The recovery of Construction and Demolition Waste (CDW) for its reincorporation into the manufacturing process of new materials is fundamental in the fight against environmental pollution, reducing the current high consumption of raw materials and boosting energy savings. The aim of this research is the study and development of a new plaster-based material in which the conglomerating material is partially replaced by dissolved recycled expanded polystyrene. In the experimental campaign, different dosages have been used in which the plaster material has been progressively replaced by the dissolved recycled expanded polystyrene, in order to subsequently carry out a physicochemical, physical and mechanical characterisation of the composites. The results obtained show how the incorporation of expanded polystyrene in solution as a partial replacement of the binder generates a homogeneous plaster composite, favouring the total integration of the waste in the matrix of the construction material finally produced. It has been observed that this new material has, in comparison with traditional plasters, a very low density, high thermal resistance and excellent plate bending behaviour. These properties position the developed material as a viable alternative in the production of more sustainable prefabricated plates and panels through the application of circular economy criteria.