Gypsum Plaster Research Articles

Enhancing Functional Properties and Mold Resistance of Gypsum Plasters with Caffeine

Caffeine is a proven bioactive substance against fungi for internal use, without any observed negative effects on properties of wood materials. However, its addition to other building materials for internal use has not yet been tested. For this reason, the effects of caffeine’s addition on selected properties of gypsum plasters were studied. Two experimental approaches were applied in the present study: (A) using an aqueous caffeine solution (20 g/L) for the preparation of gypsum plaster; and (B) immersing the gypsum plaster in the same caffeine concentration. The results showed a significant increase in the compressive strength of the plaster after 7 days of curing in laboratory conditions (variant A—46%, variant B—16%). The application of caffeine led to a substantial improvement in the water resistance of gypsum. Gypsum plasters were also exposed to a mixture of air molds. The plasters directly mixed with caffeine were about 72% less attacked by molds than the control, while immersed samples showed only a 20% reduction in mold coverage. The main conclusions of the study are that caffeine is a suitable additive for the improvement of gypsum’s compressive strength, and its addition leads to a higher resistance of gypsum against humidity and mold attacks.

Benefits of Environmentally Friendly Plaster on Mechanical Properties When Combined with Polyester Resin and Hardener Are Examined under Compression and Tension.

Recently, plaster has gained increasing attention as a mechanical and environmentally friendly option and is an effective alternative to traditional cement products. Additionally, polyester has an effective impact on the mechanical properties of materials, in addition to being one of the most environmentally friendly materials. However, studies are still ongoing to reach the best ratios of polyester resin, polyester hardener, and gypsum plaster that can improve mechanical properties. This research aims to investigate the impact of these components at various ratios (30%, 45%, and 60%) of gypsum plaster weight on the mechanical properties of plaster material. This study is carried out by conducting compression and tensile tests for three ratios, which are considered among the most important mechanical tests according to their applications. In addition, the environmental emissions resulting from the three different ratios of plaster are evaluated to determine their environmental impact. This study found that the largest ratio (30%) was the most effective from an economic and mechanical point of view, while achieving lower carbon emissions compared to the other ratios, which enhances the trend towards achieving the environmental goals of the Kingdom of Saudi Arabia's Vision 2030 to reach zero emissions. This study is highly significant both in terms of scientific research and practical application across a range of industries, since it integrates the enhancement of material performance with the achievement of environmental sustainability requirements.

Bio-Inspired Fluorescent Calcium Sulfate for the Conservation of Gypsum Plasterwork.

In this work, the potential of bio-inspired strategies for the synthesis of calcium sulfate (CaSO4·nH2O) materials for heritage conservation is explored. For this, a nonclassical multi-step crystallization mechanism to understand the effect of calcein- a fluorescent chelating agent with a high affinity for divalent cations- on the nucleation and growth of calcium sulfate phases is proposed. Moving from the nano- to the macro-scale, this strategy sets the basis for the design and production of fluorescent nano-bassanite (NB-C; CaSO4·0.5H2O), with application as a fully compatible consolidant for the conservation of historic plasterwork. Once applied to gypsum (CaSO4·2H2O) plaster specimens, cementation upon hydration of nano-bassanite results in a significant increase in mechanical strength, while intracrystalline occlusion of calcein in newly-formed gypsum cement improves its weathering resistance. Furthermore, under UV irradiation, the luminescence produced by calcein molecules occluded in gypsum crystals formed upon nano-bassanite hydration allows the easy identification of the newly deposited consolidant within the treated gypsum plaster without altering the substrate's appearance.

Development of alternative for gypsum-based plaster using magnesium carbonates from carbon capture and utilization process

This study demonstrated the use of nesquehonite (MgCO3×3 H2O) in producing plasterboard. Nesquehonite (NQ) can be activated via thermal treatment under 50–175°C, after which the dehydrated nesquehonite can hydrate to form a plaster-like product, like gypsum-based plaster. Here, we developed different blends of NQ and hemihydrate (dehydrated gypsum) to produce plaster. In addition, the influence of trace elements (i.e., sulfate and ammonium) on the reaction kinetics, mechanical properties, microstructure, phase assemblage, and evolution of the developed plasters were investigated. The target was to achieve comparable manufacturing process and compressive strength with the conventional gypsum plaster process using NQ as a major precursor. Data revealed that the mixes containing 75 % NQ obtained from 2 different synthesis routes (i.e., wet carbonation or chemically-synthesis route) attained 6–8 MPa compressive strength after 28 days of curing, which was comparable to those observed in gypsum-based products. The chemically synthesized NQ achieved the stability of NQ in the plasterboard sample, while the use of wet-carbonated NQ led to the formation of dypingite. Furthermore, the water resistance of plasterboard mixes with 100 % NQ outperformed that of gypsum, without any decline in compressive strength after water exposure.

From waste to resource: Exploring the recyclability and performance of gypsum-graphene nanofiber composites

Gypsum is a widely used building material with a variety of benefits, including good fire resistance, sound insulation, and environmental friendliness. However, gypsum disposal is commonly associated with significant environmental risks, including unhealthy gas emissions and land degradation. Gypsum recycling can help to reduce these impacts, but it can also lead to a decrease in the performance of the recycled gypsum products. This study investigated the effects of graphene nanofibers (GNFs) on the recyclability and properties of gypsum plasters. The results showed that test samples containing 1 % of GNFs exhibited improved mechanical response, with flexural and compressive strength exceeding those of neat gypsum by 30 % and 60 % respectively. This improvement is attributed to the retained functional properties of GNFs during the recycling process. Recycled gypsum pastes containing GNFs presented a more uniform and denser matrix with longer crystals, enhanced bonding, and reduced porosity. These findings suggest that GNFs can be used to facilitate the recycling of gypsum waste and to produce recycled gypsum components with improved properties. Overall, this study demonstrates the potential of GNFs to improve the sustainability and performance of recycled gypsum plasters.

Corrosion of some metallic materials embedded in gypsum

AbstractIn the construction area, as well as in the restoration of old and historical buildings, different metallic materials are frequently in contact with gypsum plaster. Due to the high porosity of gypsum plaster, and particularly in high relative humidity environments, the risk of corrosion exists. In the present work, carbon, galvanized and stainless steel, as well as copper, were embedded in gypsum plaster (with varying water/gypsum ratios) and exposed to different environmental conditions, and the corrosion rate was assessed by electrochemical techniques. Stainless steel showed very low corrosion rates, carbon and galvanized steel showed considerable corrosion rates, and copper showed moderate corrosion rates. The higher the humidity, the higher the corrosion rate, independently of the water/gypsum ratio. A comparison with results obtained for the same materials embedded in mortar was performed. Except for stainless steel, the corrosion rates obtained in gypsum are higher than those obtained in mortar, being this difference up to two orders of magnitude. The differences in the pH of both matrices explained the lower corrosion rates measured in mortar.

Change in Microstructure, Mechanical Strength, Fire Resistance, and Radiation Attenuation Properties of Gypsum Plaster with Boric Acid

AbstractIn this study, the effect of boric acid addition on the microstructure of gypsum plaster was investigated to determine an environmentally friendly gypsum additive that may enhance mechanical strength, fire resistance, and X-ray radiation attenuation properties. The mechanical strengths of bare gypsum and boric acid-added (0–0.5% by weight with respect to gypsum amount) gypsum plasters were evaluated in terms of compressive and bending strengths. The effects of the different addition procedures of boric acid (0.1% by wt.) on the fire resistance of the gypsum plasterboard were also evaluated. X-ray radiation attenuation properties of boric acid-added (0.1% by wt.) gypsum plasterboard were investigated as well. XRD, ATR-FTIR, Helium pycnometer, N2 adsorption–desorption, and SEM analysis were performed to determine the microstructural properties of gypsum plaster. XRD and ATR-FTIR analysis revealed that boric acid did not change the calcium sulfate dihydrate structure of gypsum plaster. Whereas, Helium pycnometer, N2 adsorption–desorption, and SEM analysis showed that the physical properties of gypsum changed with an increase in pore volume, skeletal density, and particle size after boric acid addition. The increase in the pore volume and particle size decreased the mechanical strength of gypsum. However, boric acid addition on the gypsum plaster plate, especially using the spraying method, enhanced the fire resistance of gypsum. Additionally, boric acid slightly enhanced the X-ray radiation attenuation properties (0.7%) of the gypsum plasterboard.

Eco-friendly construction materials: new gypsum-based composite with dregs waste from the cellulose industry

The production of materials for civil construction is a process that imposes a significant environmental impact, due to factors, such as the extraction of raw materials and the high energy consumption required to obtain the final product. Consequently, the search for new materials has grown seeking more environmentally sustainable materials. An approach to address this issue is to incorporate industrial residues as fillers to replace traditional construction materials. In this study, dregs, a waste product generated by the cellulose-paper industry, were used as a filler in gypsum composites. Gypsum plasters were replaced with dregs in proportions of 5, 15, 30, and 45%, in nature (GD x ) and Na2SO4-treated (GTD x ). The compressive strength of the resulting composites was evaluated after 21 days. Compared to gypsum plaster (17.01 MPa), the incorporation of GD5 led to a reduction of 18.6% in compressive strength (13.84 MPa), while GTD5 demonstrated mechanical properties similar to those of gypsum plaster (17.02 MPa). Composites with incorporation of up to 30% of treated dregs presented mechanical resistance above the standard international recommendations. Thus, the gypsum/dregs composite has the potential alternative to the partial replacement of plaster in civil construction, providing a more sustainable solution to the current environmental challenges.

Investigation of lightweight gypsum based on montmorillonite nanoclay with enhanced insulation properties

PurposeNowadays, thermal comfort plays a prominent role in contemporary construction practices. Appropriate thermal insulation not only offers energy efficiency benefits in buildings but also enhances occupant well-being, comfort, and productivity. Therefore, a comprehensive understanding of the thermal properties of building materials is essential. This research aims to prepare and investigate a lightweight gypsum-based composite incorporating nano montmorillonite with advanced thermal insulation properties, considering both quality and cost-effectiveness while ensuring environmental compatibility.Design/methodology/approachThis study adopts a laboratory experimental approach. A gypsum sample (without additives) and seven samples of gypsum combined with varying percentages of sodium and calcium montmorillonite nanoclays undergo extensive testing and analysis. Subsequently, the properties of these samples are compared.FindingsThe results indicate that adding montmorillonite nanoclays to gypsum composites reduces the density of the tested samples and increases their porosity. Moreover, the thermal conductivity coefficient decreases in these samples, significantly improving the thermal insulation properties of the lightweight gypsum plaster. This improvement is more pronounced in samples containing sodium montmorillonite nanoclay compared to calcium-based samples. Additionally, the investigations reveal that compressive strength decreases with the addition of montmorillonite to the samples.Originality/valueIn this research, laboratory experiments were conducted to investigate the physical and mechanical properties of gypsum plaster with varying percentages of sodium and calcium montmorillonite nanoclays. The studied properties include density, porosity, thermal conductivity coefficient, and compressive strength. Additionally, stress-strain diagrams, elastic modulus, and initial and secondary critical stresses were analyzed for each specimen.

Assessment of the Thermal Properties of Gypsum Plaster with Plastic Waste Aggregates.

Building material manufacturers must support new production models that encourage the manufacture of more efficient and sustainable products. This includes thinking about savings in the use of raw materials, a contribution to the energy efficiency of buildings during their useful life, and a reduction in the generation and deposit of waste in landfills. In this research, an analysis of the thermal properties of gypsum composites added with plastic waste is carried out using the most common methods, the steady state method and the transient plane source method, and the effect of water saturation on these composites is tested. The results show an improvement in the thermal performance of the composites (values reduced with respect to the reference by 4-7%), despite their heterogeneity, as well as a variation in the measurements carried out, depending on the method used for the measurements (variation up to 10%). It is also found that the degree of humidity negatively affects the thermal conductivity coefficient but, on the contrary, this coefficient is not altered in the composites with plastic waste, due to their lower hygroscopicity. Therefore, it is considered that the proposed eco-plasters are a good alternative to traditional plasters, with which to contribute to the achievement of the objectives of the current European directives on waste and circular economy.

Preparation and properties of phosphogypsum based plastering mortar

In order to reduce the negative impact of phosphogypsum accumulation on the environment, this paper uses phosphogypsum, magnesium slag, potassium dihydrogen phosphate, fly ash and calcium carbide slag to prepare gypsum based plaster mortar as a cementing material, and explores the optimal ratio of the composite cementing material through orthogonal experimental design. The mechanical properties of the test block were analyzed by the flexural and compressive strength of the test block, and the slurry properties were evaluated by the initial and final setting time, stability measurement, fluidity test and water resistance test. The experimental results show that when phosphogypsum: potassium magnesium phosphate: fly ash: When titanium gypsum =50:25:20:20, the strength of the composite system can reach 2.98Mpa in 60 days, and the initial setting time is 118min and the final setting time is 223min, which meets the requirements of GB/T25181-2019 building gypsum plaster mortar that the initial and final setting time is greater than 60min and less than 480min. Its fluidity is 237mm, which meets the requirement that the fluidity of GB/T25181-2019 building gypsum plaster mortar is greater than 100mm.

Spent ion-exchange resin as a new aggregate to enhance specific heat capacity of composite building materials: A case study on gypsum plaster

Spent ion exchange resin (SIER) is a by-product derived from drinking water treatment plants, possessing intriguing physicochemical properties that render it a promising ingredient for composite building materials. Surprisingly, there has been a luck of research investigating its impact on the performance of such materials. This study addresses this gap by characterizing unfired and fired gypsum-based composites with varying SIER weight ratios (10–50 wt%) and firing temperatures (300, 600, and 900°C). X-ray diffraction, scanning electron microscopy, and the hot disk method were employed to explore the effects of SIER on the composites’ thermal-mechanical features. The results revealed the significance of SIER as a promising waste-based aggregate to enhance the specific heat capacity (cp) of gypsum-based composites. With increasing SIER content and firing temperature, the composites demonstrate improved cp, reduced thermal conductivity, and decreased compressive strength. Both unfired and fired composites exhibited an increase in cp, up to 74.4% and 331.8%, respectively. The composite material achieved a noteworthy reduction in thermal conductivity, reaching 0.132 W/m.K, and a specific heat capacity increase to 4491.35 J/kg.K, which surpasses that of the control sample by more than four times (1040 J/kg.K). These newly developed composites hold significant promise as thermal energy storage materials for low-temperature building applications.

An experimental evaluation of a hybrid bio-composite based on date palm petiole fibers, expanded polystyrene waste, and gypsum plaster as a sustainable insulating building material

Gypsum plaster is essential in construction as a thermal insulator and decorative material. This study aims to protect the environment by valorizing two commonly found wastes in Algeria, namely date palm petiole fibers (DPP) and expanded polystyrene waste (EPS), to produce a gypsum plaster hybrid biocomposite material comparable to, or better than, neat gypsum plaster (NGP). Hand-made samples with different DPP mass loadings (0; 5; 10; and 15%), EPS mass ratios (0.3%), or both were used. Different morphological, mechanical, and thermophysical tests were performed on the produced hybrid composites. FTIR shows the characteristic peaks for gypsum, polystyrene, and fibers. XRD shows that NGP, EPS, and DPP are 71.58, 29.91, and 52.93% crystallinity, respectively. Compression strengths, flexural strengths, and young modulus show that EPS, DPP, or both significantly reduce all mechanical properties of prepared samples. The biocomposites produced had lower thermal conductivity (λ) (0.265–0.414 W/(m.K) at 24◦C) and bulk density (ρ) (852–925 kg/m3) than reference NGP samples witch have 0.425 W/(m.K) in thermal conductivity and 977 kg/m3 in therm of bulk density. Based on a comparative study, gypsum plaster reinforced with DPP, EPS, or both exhibits potential as a viable alternative to insulation materials, thereby offering a sustainable solution for construction purposes.

Unveiling the performance of graphene nanofiber additives in gypsum plasters: A solid vs liquid perspective

Graphene nanofibers (GNFs) are promising additives for the gypsum industry. However, their impact in different forms and configurations remains unexplored. This study delves into the effects of different types of GNF additives on the properties of gypsum plasters. Findings reveal that high-surface-area (HS) GNFs and liquid low-surface-area (LS) GNFs induced significant microstructural alterations. While rheology remained unaffected, GNFs accelerated gypsum hydration, leading to fast setting. Furthermore, these GNFs promoted the appearance of anhydrite, resulting in a porous matrix with shorter crystals and poor bonding. These microstructural changes significantly reduced both flexural and compressive strength, with losses of approximately 25%. The incorporation of surfactants further exacerbated these negative effects by limiting crystal formation and growth. Consequently, liquid GNF additives exhibited the lowest performance and durability attributes. While GNFs may impart improved thermal performance to gypsum components, their implementation can also lead to significant reductions in mechanical strength and durability. More research is required to develop additives that are more compatible and do not compromise the performance of the resulting components. Building practices interested in implementing graphene-based materials should focus on powdered additives with very low specific surface area (<100 m2/g) to minimize toxicity and negative impacts on strength and durability.

Eco-efficient plastering mortars for improved indoor comfort − The influence of A. dealbata bark addition

The passive contribution of indoor coatings to improve interior comfort is an eco-efficient challenge nowadays. Gypsum is one of the more eco-efficient binders available to produce plasters. Acacia dealbata is an invasive plant species in many countries, and the management of its wood waste for fires prevention is imperative. This study intends to evaluate the effect of using Acacia dealbata bark waste, directly after milling (raw) or with additional thermal treatment (1 h at 250 ⁰C), as an addition to an industrial gypsum-based plastering mortar to passively improve indoor comfort. To prevent the biological colonization, air lime is also added. Two clay-based plasters are used for comparison, as this type of plaster is known for being highly hygroscopic, together with a reference gypsum plaster. Results show that both the gypsum-bark mortars fulfill the standard requirements and do not show biological vulnerability. They doubled the moisture buffering of the reference gypsum plaster and got closer to the hygroscopic performance of the clay plasters. The very similar results between the two gypsum-bark mortars suggest that the thermal treatment of bark is not an eco-effective choice. So, the raw bark-added gypsum mortar is selected as a promising coating material to passively contribute for indoor comfort in an innovative, eco-efficient, way.

Effect of Al2(SO4)3 Additive on the Properties of Calcined Gypsum Prepared from Flue Gas Desulfurization

In order to upgrade the utilization of flue gas desulfurization (FGD) gypsum, crystal modifier aluminum sulfate (Al2(SO4)3) was added into FGD gypsum to prepare calcined gypsum by calcining at normal pressure, and the effect of Al2(SO4)3 addition on the performance of calcined gypsum was studied. The results show that the addition of Al2(SO4)3 to FGD gypsum is slightly beneficial to promote the crystallization of hemihydrate gypsum (HH) along the a-axis direction. The Al2(SO4)3 addition also has a quick-setting effect on gypsum plaster during the hydration process, meanwhile inhibiting the growth of the (020) crystal plane of dihydrate gypsum (DH), then promoting uniform growth and aggregation along the c-axis. The close stacking makes hardened gypsum body dense and improves the strength of calcined gypsum. The strength of calcined gypsum prepared by calcining FGD gypsum with Al2(SO4)3 of 0.6 wt.% at 170 ℃ for 2 h is the highest. 2 h and 7 d flexural strength are 3.80 MPa and 7.20 MPa, and 2 h and 7 d compressive strength are 9.05 MPa and 19.23 MPa, respectively. In addition, 2 h flexural and compressive strength of the calcined gypsum with 0.6 ~ 1.0 wt.% of Al2(SO4)3 prepared at 170 ~ 180 ℃ for 2 h increase by 16 ~ 22 % and 20 ~ 33 %, respectively, which is very advantageous for the high value-added reuse of FGD gypsum for the preparation of high-quality calcined gypsum.

Gypsum plaster waste in building: a bibliometric mapping in the Web of Science database

The present study aims to analyze the scenario relating to Brazilian and international scientific publications that deal with the reuse of gypsum plaster, carrying out a bibliometric mapping in the electronic database Web of Science (WoS) covering a period of twenty years, before and after CONAMA Resolution No. 431/2011, starting in 2001 and ending in 2020. Data collection began through exploratory research, where words and expressions were collected in abstracts and keywords from scientific productions related to the topic to create word clouds. In order to identify the scope of the three words identified as translations for gypsum plaster, an initial search was carried out in order to understand their return in numbers; then, search terms were created for searches for the three translations of the word gypsum, and a search term containing them all. The article data was exported to EndNote web, where the articles were selected, and later, using the VOSViewer software, bibliometric mapping was carried out. The database search identified 150 articles, of which 54 contained information on the recycling of gypsum waste, with the participation of 163 authors from 24 countries, the most representative being Brazil, with 13 publications. In the end, there is a lack of publications related to the topic, and that, despite some works published in relevant journals, research related to gypsum waste ends up alienating researchers due to the lack of work that supports new research, since the reference theory is essential for defining research hypotheses.

Reuse of wood biomass ash to improve thermal behavior of gypsum plasters

Huge amounts of waste are generated each year in the world. In addition, the construction sector is one of the larger producers of residues and a huge energy consumer. Thus, architects, engineers and other actors of the building sector should give solutions in order to reduce that problem. In that sense, the idea of finding solutions for the end of the service life of materials, in order to promote circularity, has been studied by several researchers. In this study, biomass wood ash has been used as aggregate for the generation of new eco-efficient gypsum plasters, for its application in new buildings and rehabilitation works. In order to conduct an exhaustive characterization of the new composites, an experimental campaign of the plasters has been conducted: dry bulk density and thermal conductivity of the plasters have been measured. The results showed that it was possible to add up to 25% of wood ash without modifying the water/gypsum ratios. Moreover, thermal conductivity of the plasters has improved up to18% when the ash was added to the mixture. Finally, the effects of using the new gypsum composites in the thermal envelope of buildings was analyzed by its usage in a rehabilitation case study simulation.

Natural additives as reinforcement for mortars: Comparative evaluation of gypsum-based plasters with pistachio shells and orange peels

This research explores the use of waste from agriculture and food production (agro-food waste) as a green additive in building gypsum plasters. The focus is on lightweight mortars made with bio-based materials, aiming for a solution that aligns with green building principles and circular economy practices. Current research prioritizes examining the physical and mechanical properties of these bio-based mortars. These mortars often have high porosity and lower weight, making them good thermal insulators and sound absorbers. While not yet widely used in construction, they hold promise as a sustainable alternative with performance comparable or even exceeding conventional plasters in thermal and acoustic insulation. In particular, the cultural premises of this study refer to the shared identity between Sicily and Tunisia, focused by a recent strategic cross-border cooperation project CUBÂTI, Culture du bâti de qualité: recherche, innovation et entreprise pour la durabilité, funded by Italy-Tunisie Programme 2014-2020. In fact, the present experimental research has focused on two materials easy to find in these countries, applying a replicable method to other regions in the Mediterranean area. In this study, the performances of gypsum-based plasters with pistachio shells and orange peels as additives were evaluated. Several tests were carried out on the developed materials to optimize their mix design, verify their mechanical and physical properties and the results of the comparative investigations showed interesting results in terms of mechanical resistance, thermal conductivity and reduction of water absorption.

Characterization of different samples of the gypsum mineral from the Araripe gypsum Pole: from macro to micro with Rietveld refinement

The gypsum mineral is composed of calcium sulfate dihydrate and has as its main application the production of gypsum plaster. In the deposits of the Araripe gypsum pole there are, in natura, different varieties, identified by the names: "Johnson", alabaster, "estrelinha", "cocadinha", "rapadura" and "boró". The characterization of the varieties of gypsum in fracture was performed by SEM and the characterization of the powder was performed by FRX and DRX. By FRX, the presence of CaO was detected with a weight range of 42.5% to 47.1%, and SO3 with a weight range of 48.1% to 53.2%. By XRD analysis, the majority gypsum phase was identified, with the presence of the crystalline planes characteristic of the mineral. From the refinement by the Rietveld method a X2 result between 0.86 and 1.11 was obtained, and it was possible to obtain information about the microstructure of the gypsum varieties and their unit cell.