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Gypsum block

A gypsum block is a lightweight, non-load-bearing construction material composed primarily of calcined gypsum (β-CaSO₄·0.5H₂O), formed into solid or hollow interlocking units similar to masonry blocks, and used for interior partitions and walls.^[1]^[2] These blocks are typically produced by mixing semi-hydrate gypsum with water and additives, then molding and drying the mixture to achieve dimensions such as 3-inch, 4-inch, or 6-inch thicknesses, 12-inch heights, and 30-inch lengths, enabling quick assembly without load-bearing structural support.^[2]^[1] Gypsum blocks have been employed in building construction since the early 20th century, gaining popularity in the United States from the 1920s through the 1950s for commercial interiors, such as in Chicago's Merchandise Mart, before declining in favor of gypsum board (drywall) by the 1970s due to faster installation methods.^[2] Despite this, they remain in use globally, particularly in Europe and for multifamily residential projects, where their sustainability—especially when made from synthetic gypsum byproducts—supports eco-friendly building practices.^[2] Key properties include high fire resistance, with wall assemblies achieving 3- to 4-hour ratings when plastered, owing to the material's non-combustible nature and water-releasing dehydration process under heat; excellent sound attenuation from its mass and 50–60% porosity; and moderate mechanical strength, with compressive values of 2.9–4.9 MPa and bulk density of 800–1,000 kg/m³.^[2]^[1] Additional benefits encompass thermal insulation, mold resistance, and low VOC emissions, though limitations like poor water resistance necessitate protection in humid environments.^[2]^[1]

Introduction and History

Definition and Basic Composition

A gypsum block is a precast building material consisting of solid, rectangular units primarily composed of gypsum plaster, which is calcium sulfate hemihydrate (CaSO₄·0.5H₂O), formed through an industrial molding process for use in non-load-bearing interior partitions and walls.^[3] These blocks are designed to provide lightweight, easy-to-install alternatives to traditional masonry, enabling quick assembly with adhesive joints to create stable interior structures.^[4] The core composition of gypsum blocks is dominated by gypsum, typically accounting for over 90% of the material by weight, derived from natural or synthetic sources such as phosphogypsum by-products.^[5] Additives are incorporated in small percentages (usually 1-5%) to optimize performance, including accelerators like potassium sulfate or sodium sulfate to speed up setting, retarders such as citric acid to control hydration timing, and reinforcements like glass fibers or vegetable fibers to enhance tensile strength and durability.^[6] During production, gypsum hemihydrate is mixed with water to form a slurry with approximately 40-50% water content by weight; this mixture is poured into molds where it sets via the hydration reaction: CaSO₄·0.5H₂O + 1.5H₂O → CaSO₄·2H₂O, resulting in calcium sulfate dihydrate crystals that bind into a dense, monolithic structure with minimal voids.^[7] Unlike gypsum board, which features a thin, hollow-core gypsum layer sandwiched between paper facings for surface applications, gypsum blocks are solid, masonry-style units without facings, suited for direct stacking and jointing.^[4] In contrast to concrete blocks, which are cement-based and denser (typically 1,800-2,400 kg/m³), gypsum blocks offer lower density—ranging from 850 to 1,000 kg/m³ for standard types—making them easier to handle while remaining gypsum-based for superior workability in dry construction.^[8]

Historical Development and Usage

The use of gypsum as a building material traces back to ancient civilizations, with evidence of gypsum blocks and plaster applied over woven straw lath dating to approximately 3700 BCE in Egypt, where it was employed in pyramid construction.^[9] While gypsum had been utilized for millennia in various forms, modern gypsum blocks emerged in late 19th-century Europe as a fire-resistant alternative to traditional lime plaster for interior partitions and structural elements. In the United States, gypsum blocks were introduced around 1910, with the United States Gypsum Company (USG) launching its Pyrobar gypsum tile product in the early 1900s as a non-combustible option for commercial interiors.^[10]^[2] Gypsum blocks reached peak popularity in the US from the 1920s through the early 1960s, particularly for non-load-bearing partitions in large commercial buildings, such as the Merchandise Mart in Chicago completed in 1930, which featured extensive gypsum block usage for its fire-resistive properties.^[2] Early US patents for reinforced gypsum blocks appeared in the 1920s, supporting their widespread adoption in fire-rated assemblies. However, following the peak in the early 1960s, usage declined through the 1970s, largely supplanted by the invention of gypsum wallboard (drywall) in 1916 by USG, which offered greater cost efficiency, faster installation, and labor savings.^[11]^[2] US manufacturing of gypsum blocks ceased by the mid-1970s as drywall dominated the market.^[2] In Europe, gypsum blocks persisted beyond the US decline, gaining renewed prominence after World War II for rapid reconstruction of non-load-bearing walls amid widespread housing shortages.^[12] Standardization efforts in the 20th century, culminating in the European Norm EN 12859 for gypsum blocks, facilitated their consistent production and application across the continent.^[13] Today, they remain in common use in countries like Germany, France, and the UK for interior partitions in both residential and commercial projects, valued for sustainability and ease of handling. In the 21st century, gypsum blocks have spread globally to Asia and Latin America, driven by demand for affordable, lightweight materials in emerging affordable housing markets.^[14]^[15]

Manufacturing Process

Materials and Preparation

Gypsum blocks are primarily produced from natural or synthetic gypsum as the base raw material, which is calcined to form calcium sulfate hemihydrate (stucco) at temperatures between 150°C and 180°C to drive off water of crystallization without decomposition.^[16] Natural gypsum, a mineral form of calcium sulfate dihydrate (CaSO₄·2H₂O), is mined from sedimentary deposits worldwide, with major sources in the United States (e.g., Michigan and Oklahoma), Mexico, and Europe (e.g., Spain and France), where purity typically ranges from 75% to 95% CaSO₄·2H₂O content.^[17] Synthetic gypsum, derived as a byproduct from flue-gas desulfurization (FGD) processes in coal-fired power plants, offers a high-purity alternative (often exceeding 95% CaSO₄·2H₂O) and is increasingly used to supplement natural supplies, reducing reliance on mining.^[18] To enhance performance, small quantities of additives are incorporated during preparation, including accelerators such as potassium sulfate to promote faster hydration and setting.^[19] Retarders (e.g., citric acid or sodium citrate) are added to extend working time and ensure uniform mixing.^[20] Optional fillers like glass fibers, cellulose fibers, or vermiculite may be included to adjust density and improve handling, particularly for lightweight variants. Up to 20% recycled gypsum from post-consumer drywall waste can be integrated into the mix, promoting sustainability while maintaining product quality after purification to remove paper and contaminants.^[21] Preparation begins with crushing and grinding the raw gypsum to a fineness of 100-200 mesh (approximately 150-75 μm particle size) to ensure uniform reactivity during hydration.^[22] Additives are then precisely weighed and dry-blended with the calcined stucco in industrial mixers to achieve homogeneity.^[23] Quality control is critical, with inputs tested for minimum purity equivalent to 85% CaSO₄·2H₂O to minimize impurities such as silica or iron oxides that could affect setting or strength; spectroscopic and chemical assays verify compliance before proceeding.^[24] This process supports gypsum's environmental advantages, as calcination requires about one-third the CO₂ emissions of cement production (0.08 t CO₂ per tonne of gypsum blocks versus approximately 0.8-1 t for cement), primarily due to the absence of decarbonation reactions.^[16]

Production Techniques

The production of gypsum blocks involves transforming calcined gypsum stucco into a pourable slurry and shaping it through automated industrial processes. The core process starts with mixing the prepared stucco with water in high-shear or tiltable mixers to create a homogeneous slurry, employing a water-to-stucco ratio typically ranging from 0.35 to 0.45 to achieve the desired density and workability for dense blocks. This mixing duration is generally 2 to 5 minutes, ensuring even dispersion of any additives while avoiding excessive air incorporation.^[25] The slurry is then poured into molds, often silicone or hard-chrome-plated steel forms on conveyor-based automated lines, to form blocks with precise dimensions and features like tongue-and-groove joints. Vibration is applied during pouring to eliminate air pockets and promote uniform settling, enhancing structural integrity. Initial setting occurs rapidly, within 5 to 10 minutes at temperatures of 20 to 30°C, allowing the gypsum crystals to interlock and gain sufficient rigidity. Demolding follows after 20 to 30 minutes, once the blocks have achieved green strength without deformation. Full curing then takes place over 24 to 48 hours, either through ambient hydration or accelerated methods like steam curing, to complete the hydration reaction and attain final hardness.^[23] Post-curing, blocks undergo finishing steps, including edge trimming to refine tongue-and-groove profiles for seamless assembly, and optional surface treatments such as wax coatings to improve paint adhesion and moisture resistance. Quality control involves sorting based on density, dimensions, and visual defects, ensuring compliance with standards before packaging. In modern facilities, advancements like Grenzebach automated production lines integrate dosing, forming, and handling systems, achieving outputs of 100 to 300 blocks per hour and annual plant capacities of 100,000 to 300,000 m².^[23]^[26] Recent developments include enhanced lines with improved thermal insulation additives, such as Knauf's 2022 high-performance blocks.^[15] Energy efficiency is enhanced through waste heat recovery in drying processes, reducing overall consumption. Waste management practices include recycling slurry scraps and trim waste back into the mix via closed-loop systems, minimizing gypsum loss to less than 5%.^[5]

Specifications and Standards

Dimensions and Types

Gypsum blocks are produced in standardized dimensions to facilitate modular construction and efficient wall assembly. In Europe, the EN 12859 standard specifies nominal dimensions of 666 mm in length and 500 mm in height, with thicknesses ranging from 50 mm to 150 mm, allowing three blocks to cover 1 m² of wall area.^[27] Historically in the United States, gypsum blocks were manufactured with thicknesses of 3 to 6 inches (76 to 152 mm), lengths of 24 to 30 inches (610 to 762 mm), and heights of 12 inches (305 mm).^[2]^[28] Gypsum blocks are categorized by density classes as defined in EN 12859, which influence their suitability for different applications. The low-density class (L) ranges from 600 to 800 kg/m³ and often incorporates additives like perlite to enhance thermal insulation.^[29] The medium-density class (M), at 800 to 1100 kg/m³, serves general partitioning needs with balanced properties.^[30] High-density class (D) ranges from 1100 to 1500 kg/m³, providing greater impact resistance for demanding environments.^[31] The predominant shape for gypsum blocks is rectangular, featuring tongue-and-groove joints on the vertical edges to ensure stable, interlocking assembly without additional mortar in many cases.^[32] Specialized variants include curved blocks designed for arched structures and perforated types that incorporate channels for running wiring or conduits.^[23] Dimensional tolerances under EN 12859 are tight to maintain uniformity, with allowances of ±2 mm for length and height, and ±1 mm for thickness. Block weights typically range from 10 to 25 kg, varying by size and density class.^[33] Prior to the 1950s, gypsum block dimensions exhibited significant variation across manufacturers and regions, complicating construction. Post-2000 standardization, particularly through EN 12859 introduced in 2001, has promoted consistent modular sizing to support modern prefabricated building practices.^[27]

Quality Requirements and Testing

Gypsum blocks must comply with established standards to ensure structural integrity, safety, and environmental suitability in construction applications. In Europe, the primary standard is EN 12859, which defines the characteristics, performance requirements, and test methods for gypsum blocks with smooth faces intended for non-load-bearing internal partitions.^[27] This standard addresses key attributes such as reaction to fire, flexural strength, impact resistance, and release of dangerous substances to verify compliance. Gypsum blocks are classified into strength classes A (normal) and R (reinforced), which determine the minimum breaking loads in flexural testing. In the United States, the historical ASTM C52 standard specifies requirements for gypsum partition tile or block, including weight, dimensions, and mechanical strength, though it dates to 1954 and has been withdrawn in 1982, largely superseded by modern building codes.^[34] Testing procedures for gypsum blocks focus on mechanical performance and durability to meet minimum thresholds. Flexural strength is determined via a three-point bending test on block samples, with minimum breaking loads specified depending on density and strength class (e.g., 2.0 kN horizontally for medium-density class A blocks).^[27] For hydrophobic variants, water absorption is assessed through an immersion test to verify low moisture uptake. Dimensional accuracy is verified using calipers and scales to confirm tolerances, as deviations can affect assembly and overall wall performance.^[27] Additional tests evaluate other critical properties. Surface hardness is measured using a scratch test method outlined in EN 12859 Annex B, ensuring the blocks withstand minor impacts without surface damage.^[29] The release of dangerous substances is assessed according to relevant European test methods, such as EN 16516 for construction products, to ensure no harmful quantities, including VOCs like formaldehyde, are emitted when used as intended.^[27]^[35] Certification processes enforce these standards through regulatory compliance and quality assurance. In the European Union, CE marking is mandatory for gypsum blocks, indicating conformity with EN 12859 via factory production control, initial type testing, and ongoing surveillance by notified bodies.^[36] Ongoing quality control involves batch sampling, typically 1% of production or a minimum of three blocks per batch, subjected to the above tests to maintain consistency across manufacturing runs.^[37] Since 2020, sustainability testing has gained prominence, particularly for recycled content integration. Standards and guidelines in regions like the EU now emphasize verification of minimum recycled gypsum content, often at least 10% in select markets, through compositional analysis to support circular economy principles in production.^[38]

Physical and Performance Properties

Mechanical and Structural Properties

Gypsum blocks exhibit compressive strengths typically ranging from 2 to 5 MPa, depending on their density, which renders them suitable for constructing non-load-bearing interior walls up to 4-5 meters in height.^[39] The modulus of elasticity for these blocks generally falls between 1.5 and 3 GPa, contributing to their ability to withstand vertical loads without excessive deformation in partition applications.^[40] Flexural and tensile strengths of gypsum blocks are in the range of 1 to 3 MPa, reflecting their brittle nature, while shear resistance is primarily achieved through the interlocking design of their tongue-and-groove joints, which enhance horizontal stability in assembled walls.^[41] Impact resistance remains low, limiting their use in high-traffic areas unless reinforced with additional framing or surfacing.^[39] The void-free structure of solid gypsum blocks provides inherent rigidity, supporting overall structural stability, with a low thermal expansion coefficient of approximately 0.01 mm/m/°C that minimizes dimensional changes under temperature variations.^[42] Moisture-induced expansion is limited to less than 0.5% at 90% relative humidity, preserving integrity in controlled interior environments.^[42] In terms of durability, gypsum blocks demonstrate resistance to mold growth when maintained in dry conditions and offer a lifespan exceeding 50 years in interior applications, with no curing shrinkage occurring during setting, unlike cement-based materials.^[43]^[44] Compared to concrete blocks, gypsum blocks provide a superior weight-to-strength ratio, weighing about one-third as much while achieving comparable stability for non-structural partitions.^[45] Density variations directly influence these strength properties, with lower-density blocks prioritizing lightness over peak load capacity.^[39]

Thermal, Acoustic, and Fire Properties

Gypsum blocks demonstrate favorable thermal properties due to their composition and structure, making them suitable for energy-efficient building envelopes. The material's thermal conductivity typically ranges from 0.17 to 0.3 W/m·K, which is lower than that of common brick (0.6–1.0 W/m·K), enabling effective heat retention and reduced energy loss in walls.^[46]^[47] For a standard 100 mm thick gypsum block wall, this results in an R-value of 0.3–0.6 m²·K/W, influenced by factors such as block density and whether the design is solid or hollow.^[48] Additionally, gypsum's chemically bound water content, approximately 21% by weight, enhances thermal performance by absorbing heat through endothermic dehydration processes, which release energy slowly and stabilize indoor temperatures.^[49] Thermal properties are evaluated using methods like the guarded hot plate apparatus, which measures steady-state heat flow through samples under controlled conditions.^[50] In terms of acoustic performance, gypsum blocks provide moderate sound insulation, particularly for non-structural partitions. A single 100 mm layer achieves a Sound Transmission Class (STC) rating of approximately 40 dB, effectively reducing airborne noise in environments like offices and hotels.^[51] This performance follows the mass law of acoustics, where sound reduction increases by approximately 6 dB for each doubling of surface mass, with gypsum blocks benefiting from their inherent density around 700–900 kg/m³.^[52] Acoustic testing adheres to ISO 10140 standards, involving laboratory measurement of transmission loss across frequencies from 100 to 5000 Hz in reverberation rooms.^[52] Perforated or hollow gypsum block variants further enhance acoustics by 5–10 dB through improved sound absorption within internal voids, outperforming solid blocks at higher surface masses above 70 kg/m².^[51] Gypsum blocks excel in fire safety, classified as non-combustible under Class A1 of EN 13501-1, meaning they contribute no fuel to fire spread and produce minimal smoke or flaming droplets.^[8] For a 100 mm thick wall assembly, fire resistance ratings reach 120–240 minutes per ASTM E119 testing, during which the material maintains structural integrity without excessive temperature rise on the unexposed side.^[53] This endurance stems from the endothermic release of bound water as vapor starting at around 100°C, which absorbs heat (approximately 2.4 MJ/kg) and forms a protective steam barrier, delaying calcination and ignition of adjacent materials.^[49] Fire endurance is assessed via standardized furnace exposure in ASTM E119 or equivalent protocols, simulating time-temperature curves up to 1093°C for specified durations.^[53]

Applications and Construction

Common Uses in Building

Gypsum blocks are primarily employed for constructing interior non-load-bearing partitions in residential, commercial, and institutional buildings, such as offices, schools, and hospitals, where their lightweight nature and ease of assembly facilitate rapid division of spaces.^[54]^[55]^[2] Specific applications include the creation of curved walls through cutting and shaping, utility shafts for enclosing mechanical, electrical, and plumbing (MEP) systems with integrated chases for wiring and piping, and sound barriers in environments like auditoriums, where they achieve sound reduction indices up to 68 dB in double-layer configurations.^[56]^[8] Historically in the United States, gypsum blocks were used in early 20th-century skyscrapers, such as Chicago's Merchandise Mart completed in 1930, for fireproofing structural elements and forming interior partitions up to 30 feet high.^[2] In modern construction, gypsum blocks enable slim walls with thicknesses of 50-80 mm, which are thinner than traditional masonry partitions and thus optimize floor space utilization in dense urban developments.^[56] Their compatibility with MEP systems allows seamless integration of ventilation, heating, and electrical components during any construction phase. In Europe, they represent a significant portion of interior partition solutions, contributing to the annual coverage of over 1,500 million square meters of building interiors with gypsum-based products.^[55]^[56] Limitations restrict gypsum blocks to dry interior environments, as they require protection from extensive moisture to prevent degradation, with maximum unsupported heights reaching 7.5 meters in single-layer setups. Case examples include their widespread adoption in post-World War II European housing reconstruction for quick partition erection in residential units.^[8]^[2]^[55]

Installation and Construction Methods

Gypsum blocks are typically installed using a dry stacking technique that relies on their tongue-and-groove design for a friction fit, eliminating the need for mortar between individual blocks to ensure quick assembly and structural integrity.^[57]^[45] Preparation begins with leveling the base using a 1-2 cm bed of gypsum slurry or mortar to create a stable foundation, followed by alignment with string lines for plumb and level courses; blocks should be stored in a dry environment prior to installation.^[58]^[3] This method allows for non-load-bearing partition walls up to 10-12 meters high without additional stiffeners, depending on block thickness (e.g., 80-100 mm).^[57] The stacking process involves laying blocks in a running or half-bond pattern, starting from the base and building vertically or horizontally course by course, with the tongue-and-groove edges interlocked for stability; minimal wetting with a brush may be applied if needed for adhesion in the joints. Temporary bracing is installed every 1-2 meters during construction to prevent shifting until the wall is complete and secured. For openings such as doors, which typically account for 10-20% of wall area, blocks are cut using a carbide-tipped saw to fit precisely around frames. Anchoring to the surrounding structure occurs with metal clips or ties spaced every 1.2 meters vertically and horizontally to enhance stability.^[58]^[2]^[3] This approach leverages the blocks' standard dimensions (e.g., 500 x 667 x 80-100 mm) for minimal on-site adjustments, as detailed in specifications for dimensions and types.^[57] Finishing requires sealing any necessary joints with gypsum adhesive for a seamless surface, after which plaster, paint, or wallpaper can be applied directly due to the blocks' smooth faces; no preliminary skim coat or chapisco layer is typically needed. Essential tools include trowels for the base mortar, spirit levels and spacers for alignment, string lines for plumb, and carbide saws for cutting; installation rates achieve 20-40 m² per worker per day, significantly faster than traditional masonry at around 5-10 m² per day.^[3]^[57]^[45]^[59] Safety considerations during installation emphasize dust control measures, such as wet cutting or ventilation when using saws to minimize inhalation of gypsum particles, and proper handling of blocks weighing over 15 kg, often with mechanical lifts or team assistance to prevent strain; workers should wear protective gear including masks, gloves, and eye protection. These practices ensure compliance with structural stability requirements while prioritizing worker safety and efficient workflow.^[58]^[2]

Regional Differences

Usage in the United States

Gypsum blocks, also known as gypsum tiles, achieved significant popularity in United States construction during the early 20th century, particularly for interior non-load-bearing partitions in commercial buildings. Introduced as a fire-resistant alternative to traditional masonry, they were widely adopted from the 1900s through the 1920s and into the mid-20th century, serving as a substrate for gypsum plaster finishes. Major manufacturers, including the United States Gypsum Company (USG), produced products like Pyrobar gypsum tiles starting in 1903, capitalizing on the material's inherent fireproof qualities to meet growing demands for safer urban construction.^[10]^[2] The decline of gypsum blocks in the U.S. began in the 1930s and accelerated after World War II, primarily due to the rise of gypsum wallboard (drywall), which offered faster installation times and lower overall costs compared to laying individual blocks. While gypsum blocks required labor-intensive assembly similar to brickwork, drywall sheets could be hung on metal or wood studs in a fraction of the time, reducing labor expenses and enabling scalability for postwar housing booms. By the mid-1950s, drywall accounted for approximately 50% of new home wall finishes, overshadowing block systems. USG and other producers phased out marketing for gypsum blocks by the mid-1970s, with the last domestic manufacturing plants closing around that period as market demand shifted entirely to panel-based systems.^[2]^[9] Today, there is no domestic production of gypsum blocks in the United States, and they are rarely imported, limited to niche applications such as historic building restorations where matching original materials is required. Building codes, including the 2021 International Building Code (IBC), permit gypsum-based partitions but emphasize modern systems like metal-stud framing with gypsum panels for their compliance with updated fire, seismic, and energy efficiency standards. Alternatives such as Type X gypsum wallboard on steel studs provide comparable fire-resistance ratings (up to 2-4 hours) and superior sound transmission class (STC) values without the installation challenges of blocks. Legacy gypsum block installations in pre-1930 structures often necessitate specialized maintenance, including crack repairs and plaster repointing, to address issues like moisture absorption and joint deterioration over time.^[2]^[60] Regulatory support for gypsum blocks has waned, with ASTM International's standard C52 for gypsum partition tile or block now archived and unchanged since earlier editions, reflecting the material's obsolescence. No new certifications or testing protocols have been developed for gypsum blocks in the U.S. since the 1980s, further directing industry focus toward gypsum board standards like ASTM C1396.^[34]^[61]

Usage in Europe and Elsewhere

In Europe, gypsum blocks are a standard material for non-load-bearing internal partitions in residential and commercial buildings, governed by the European standard EN 12859, which has been in place since 2001 and specifies definitions, requirements, and test methods for their characteristics and performance, making compliance mandatory for CE marking under the Construction Products Regulation.^[62]^[63] Germany and France lead production, supported by an industry operating 160 factories and 154 quarries, with a total turnover of over €7.7 billion as of 2023.^[64] Together with plasterboard, gypsum blocks cover more than 1,500 million square meters of interior surfaces annually across the region as of the early 2010s.^[55] Globally, the gypsum block market reached approximately USD 1.5 billion in 2023 and is projected to grow to USD 2.8 billion by 2032, driven by demand in emerging regions.^[65] Usage is strong in the Middle East, particularly in the UAE where they are employed in hotel construction for interior walls and ceilings, supported by local production capacities exceeding 50 million m² annually for gypsum products.^[66] In Latin America, Brazil incorporates gypsum blocks in a notable share of partition systems, while in Asia, India utilizes them extensively for affordable housing projects.^[14] European exports account for a significant portion of global trade, with the EU as a major supplier of gypsum materials.^[67] Adaptations for specific environments include the addition of hydrophobic agents to gypsum blocks for improved moisture resistance in humid climates.^[68] In seismic-prone areas, reinforced joints are applied in line with Eurocode 8 guidelines to enhance structural integrity during earthquakes.^[68] Market growth is bolstered by the EU Green Deal, which encourages the use of recycled gypsum in building materials, allowing up to 30% recycled content in products like gypsum blocks to support circular economy goals.^[69] Post-2020, the sector has seen annual growth of around 6%, fueled by the rise of modular construction techniques that favor lightweight, prefabricated elements. As of 2025, the industry continues to advance circular economy practices, with some manufacturers incorporating higher recycled gypsum content.^[65]^[70] Representative examples include their application in UK schools for acoustic partitions, where systems like those from British Gypsum provide high sound insulation in educational settings.^[71] In China, factories produce slim 50 mm gypsum blocks tailored for efficient interior partitioning in urban developments.^[72]

Advantages and Limitations

Benefits of Gypsum Blocks

Gypsum blocks enable rapid construction through dry stacking methods that eliminate the need for mortar, wet processes, or extended drying times, allowing walls to be erected and finished in a single day. This approach reduces labor requirements compared to traditional wet masonry techniques, as no specialized wet trades are involved and assembly relies on simple gypsum bonding compounds.^[55]^[56] The slim profile of gypsum blocks, typically 60-100 mm thick, optimizes usable interior space compared to thicker masonry alternatives, while their lightweight nature—about 50% the weight of concrete blocks—lowers foundation and structural loads, yielding significant material and engineering cost reductions. Material costs range from $5-10 per square meter, and total wall assembly costs are lower due to minimized waste and simplified installation. Their smooth, pre-finished surfaces permit immediate paintability without additional plastering, further streamlining finishing processes.^[56]^[4]^[73] From a sustainability perspective, gypsum blocks are 100% recyclable, with waste easily crushed and reused to produce new plaster or blocks, minimizing landfill use and supporting circular construction practices. They exhibit low embodied energy at around 1.8 MJ/kg, comparable to concrete (1.1-2.0 MJ/kg), and quarrying natural gypsum has minimal environmental impact due to abundant reserves and low-energy processing at 135-180°C. Durability exceeding 50 years contributes to lifecycle savings by reducing replacement needs and maintenance.^[74]^[55]^[56]^[75]

Drawbacks and Considerations

Gypsum blocks exhibit significant vulnerability to moisture, capable of absorbing up to 20% of their weight in water, which can reduce compressive strength by 30-50% due to partial dissolution and softening of the material.^[76]^[77] This susceptibility renders them unsuitable for high-humidity environments such as bathrooms or kitchens unless treated with waterproofing agents like silicone sealants or hydrophobic coatings to create a barrier against water ingress.^[78] As non-structural elements, gypsum blocks are limited to partition walls and cannot support substantial superimposed loads, typically limited to light applications to avoid failure under compression or shear.^[58] Their inherent brittleness also makes them prone to damage from impacts, with low dent resistance compared to denser materials like concrete, often resulting in cracks or fractures during handling or minor collisions.^[79] As of 2025, in regions like the United States and Canada, gypsum blocks are scarce due to discontinued domestic manufacturing, necessitating imports that elevate project costs through tariffs, shipping, and supply chain logistics.^[2]^[80] Cutting gypsum blocks generates fine dust that, while free of silica, acts as a respiratory irritant requiring proper ventilation and personal protective equipment to prevent throat irritation, coughing, or long-term airway issues among workers.^[81] Environmentally, gypsum block production involves calcination, a process that consumes energy at relatively low temperatures compared to cement but still contributes to greenhouse gas emissions from heating.^[82] Synthetic gypsum sourced from power plant flue gas desulfurization may include trace heavy metals, though levels are regulated to remain below thresholds like those in EPA 40 CFR Part 503 to minimize soil or water contamination risks.^[83] To mitigate these drawbacks, gypsum blocks should be confined to dry interior zones away from moisture exposure, with hybrid systems combining them with drywall panels offering enhanced versatility for non-load-bearing applications.^[56] However, end-of-life recycling faces challenges, particularly when mixed with other construction waste, due to limited infrastructure for separation and processing, which can hinder circular economy goals and increase landfill disposal.^[84]

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[PDF] Living with Gypsum: From Raw Material to Finished Products
prepare European standards for Gypsum plasters, Gypsum units,. Gypsum based and ancillary products as well as for design and application of the products ...
[19]
FGD Gypsum Production Process
FGD gypsum is made from gas captured at coal plants. The process involves oxidation of sludge, then washing to remove impurities, creating high-quality gypsum.
[20]
Raw Materials for Drywall & Gypsum Putty - Bisley International
Bisley supplies dispersants, accelerators, de-foamers, air-entrainers, retarders, and specialty additives for gypsum putty, including potassium sulfate, TIBP, ...
[21]
The role and function of gypsum retarder - Mixeon
Jan 10, 2025 · Gypsum retarder is an additive used to slow down the setting time of gypsum-based products. The setting process of gypsum involves the hydration of calcium ...
[22]
[PDF] BEYOND RETARDING EFFECT - SICIT Group
It is state of the art to combine a starter (BMA) with a retarder (PlastRetard XCL) and an accelerator (potassium sulphate) to delay the initial setting time ...Missing: sulfate | Show results with:sulfate
[23]
[PDF] RECYCLING GYPSUM DRYWALL RECOVERED FROM ...
Recycled gypsum will typically represent as much as 10% to 20% of some manufacturers' gypsum feedstock. Recycling of scrap post-consumer gypsum wallboard at ...
[24]
[PDF] the technology of the manufacture of gypsum products
GYPSUM PRODUCTS*. ABSTRACT. In 1904 the value of crude and calcined gypsum produced in the United States was $2,750,000, with a tonnage of less than 1,000,000 ...
[25]
Production lines for gypsum blocks - Grenzebach
To produce gypsum blocks, Grenzebach supplies individually tailored production processes according to your product requirements: from single components to ...<|control11|><|separator|>
[26]
C471M Standard Test Methods for Chemical Analysis of Gypsum ...
Apr 5, 2024 · These test methods cover the chemical analysis of gypsum and gypsum panel products, including gypsum ready-mixed plaster, gypsum wood-fibered plaster, and ...Missing: raw | Show results with:raw
[27]
CA2341466C - Gypsum wallboard, and method of making same
Alpha-type stucco generally requires water usage of about 34 to about 45 cubic centimeters per 100 grams of calcined gypsum in order to form 25 a readily ...<|control11|><|separator|>
[28]
[PDF] Plaster Mixing Procedures - USG
A check on the ratio can be made at any time by weighing the slurry in a container of known volume. For example, at a consistency of 70cc (70 parts water per ...
[29]
Gypsum Block Production Line
Gypsum Block Machine Capacity ; Capacity/year, Block Length, Block, Block Thick, Blocks/Batch ; 100,000sqm, 666 mm, 500 mm, 80-150 mm, 7 blocks ; 200,000sqm, 666 ...
[30]
https://www.multigips.de/en/gypsum-blocks/products/density-class-m/
[31]
[PDF] Gypsum Partition Tile
Part III contains the American Society for Testing. Materials Standard Specifications for Gypsum Partition. Tile or Block (C52-27). It is recommended that ...Missing: ASTM | Show results with:ASTM
[32]
BS en 12859-2011 PDF | PDF | Density | Building Insulation - Scribd
Rating 5.0 (1) 8 Marking, labelling and packaging. Gypsum blocks complying with this European Standard shall be clearly marked on the block or label or on the packaging or ...Missing: raw | Show results with:raw
[33]
Gypsum Blocks EN 12859 - Multigips
Dimension (length x height) 666 x 500 mm ; Block requirement per 1 m² wall 3 ; Water absorption class H3 ; Water absorption no requirements ; Color natural white
[34]
Gypsum Blocks EN 12859 - Multigips
Solid Gypsum Block Wall thickness 100 mm. Density approx. 1,400 kg/m³. Non-combustible, Euro class A1 · Solid Gypsum Block Wall thickness 100 mm. Density approx.
[35]
High-Precision Gypsum Block - HANMERO WALL PANEL
The top and bottom surfaces of the gypsum blocks feature tongue-and-groove joints, which interlock to provide horizontal shear resistance and impact strength, ...
[36]
Moisture Resistant Block MH80-0.85, 10 m², 30 pcs/pallet - Kipsik
€600.00Block dimensions. Width: 666 mm. Height: 500 mm. Thickness: 80 mm. Color ... Gypsum board 2.6m GKB, standard plasterboard, 60pcs/pallet · Building block ...
[37]
Gypsum Concrete - an overview | ScienceDirect Topics
Gypsum concrete is defined as a building material composed of a gypsum mixture, which exhibits satisfactory environmental properties and strength that is ...
[38]
CE marking of construction products - RINA.org
All construction products designed for use in a permanent manner must be CE-marked in order to circulate freely and be marketed in the European Union.
[39]
Gypsum Blocks. Definitions, Requirements and Test Methods. - Scribd
Rating 5.0 (2) Gypsum blocks are manufactured in two types of strength class A and R (see 4.10). Gypsum blocks are manufactured in three types of density Low, Medium and Dense ...
[40]
Sustainable lightweight gypsum from recycled waste: Microstructure ...
This study explores a sustainable method for producing lightweight gypsum components by reusing gypsum waste (GW) as a secondary raw material.
[41]
[PDF] Determination of Young's Modulus of Gypsum Blocks Using Two ...
An average value of the static Young's modulus is 1.72 GPa (without the value of the block 6B).
[42]
Gypsum Block Catalogue | PDF | Materials - Scribd
Bending Strength > 2 MPa Mould Resistance Pass (BS 5980 – App. B) Setting Time 1.5 Hours Pot Life 8 Months. SUMMARY OF STRENGTH AND ROBUSTNESS TESTS TO BS 5234- ...
[43]
Drywall Plasterboard Coefficients of Thermal & Moisture ...
Thermal Coefficient of Linear Expansion = 16.2 x 10-6 mm/(mm°C) –at temperature range 4°C to 38°C · Hygrometric Coefficient of Expansion = 7.2 x 10-6 mm/mm/%RH – ...
[44]
What Are The Different Advantages Of Gypsum Plaster? - Finecrete
Rating 4.7 (18,482) Compared to cement and water, gypsum reaction generates less heat. Consequently, gypsum plaster has fewer shrinkage cracks than typical cement plaster. No time ...
[45]
MgO Board vs Gypsum Board for Mold Resistance and Durability
Apr 25, 2025 · MgO boards absorb only 0.34% moisture, while gypsum boards absorb nearly 3%, making MgO boards far more effective at resisting mold and water damage.Missing: lifespan | Show results with:lifespan
[46]
Advantages of Jumbo Gypsum Blocks - Marshal
The Jumbo water repellent gypsum block possesses high density (1100 – 1200 kg/m3), superior compressive strength (10-14 MPa) and flexural strength (4 MPa).
[47]
Thermal Conductivity of Common Materials - Solids, Liquids and ...
Gypsum board, 0.17. Hairfelt, 0.05. Hardboard high density, 0.15. Hardwoods (oak ... the thermal resistance R. Related Searches. thermal conductivity • heat ...
[48]
[PDF] thermal conductivity of construction materials based on gypsum
The traditional untreated gypsum in the form of solid cast block has the greatest thermal conductivity and density. The thermal conductivity corresponds to ...
[49]
High-Strength and Heat-Insulating Cellular Building Concrete Based ...
Dec 22, 2022 · The main properties of cellular concrete are its density (200–1200 kg/m3), thermal conductivity (0.06–0.40 W/mK), and compressive strength (0.4– ...
[50]
The Science of Fire-Resistant Drywall: Types, Testing and Safety
Jun 10, 2024 · Gypsum board assemblies are tested in accordance with ASTM E119, Standard Test Methods for Fire Tests of Building Construction and Materials.
[51]
(PDF) An extended hot plate method for measurement of thermal ...
Calculated thermal conductivity values obtained using a gypsum plaster sample, which specific heat capacity variation with temperature is accurately measured, ...
[52]
Sound insulation of gypsum block partitions: An analysis of single ...
A similar result is presented in Ref. [20] where 10 cm-thick gypsum blocks, with a density of 850 kg/m³, can achieve 40 dB sound insulation.
[53]
Sound insulation of gypsum block partitions: An analysis of single ...
Aug 9, 2025 · This paper presents an evaluation regarding the sound insulation of simple walls built with gypsum blocks, both solid and hollow, ...<|control11|><|separator|>
[54]
Fire Performance | USG
... gypsum drywall is its fire resistance. This is provided by the principal raw ... fire of standard intensity, as defined by ASTM E119 and UL263.
[55]
EPD-IES-0001228:002 (S-P-01228) Gypsum block – Alba® 100
Mar 9, 2018 · Gypsum Block in accordance with SN EN 12859, with a specific weight of 1000 kg/m3. Gypsum blocks are primarily used in the construction of ...Missing: density | Show results with:density
[56]
Use in Buildings - Eurogypsum
Gypsum blocks are used for indoor partitions and gypsum tiles for ceilings. Gypsum blocks are easy to install quickly. They are used in particular for walls ...
[57]
[PDF] Simply Gypsum Blocks - Multigips
Solid high quality interior rooms with solid wall building material. Dry wall construction without interior plaster. Comparatively low mass per unit area.
[58]
what is victor gypsum block? - Victor Building Materials (HK) Limited
Easy Installation. The lightweight and tongue-and-groove design of Victor Gypsum Block make it easy to install, saving construction time and labor costs. · Solid ...
[59]
[PDF] IS 3630 (1992): Construction of Non-load Bearing Gypsum Block ...
This standard is intended to provide guidance with regard to selection of gypsum blocks and the methods of construction ... b) Installation of frames for doors, ...
[60]
CHAPTER 25 GYPSUM BOARD GYPSUM PANEL PRODUCTS ...
Gypsum wallboard or gypsum plaster shall not be used in any exterior surface where such gypsum construction will be exposed directly to the weather. Gypsum ...
[61]
C1396/C1396M Standard Specification for Gypsum Board - ASTM
Oct 4, 2024 · This specification covers gypsum boards which include the following: gypsum wallboard for use on walls, ceilings, or partitions and that affords a surface ...
[62]
https://standards.iteh.ai/catalog/standards/cen/715bd964-b32f-45ee-b130-0fb19e63a541/en-12859-2001
[63]
[PDF] CE-MARKING OF CONSTRUCTION PRODUCTS - STEP BY STEP
Nov 1, 2014 · The products included in the scope (first chapter of the standards) have to be CE marked according to the dates in the table. When the “ ...Missing: gypsum 12859 2001
[64]
[PDF] Background II. The European Gypsum Industry in Figures
Germany, France and the UK use between 3 and 4 square meters per person. While this figure describes the usage rate of gypsum board in these more well developed ...
[65]
Gypsum Block Market Report | Global Forecast From 2025 To 2033
In 2023, the global gypsum block market size was valued at approximately USD 1.5 billion and is projected to reach around USD 2.8 billion by 2032.Gypsum Block Market Outlook · Product Type Analysis · Report Scope
[66]
Top 10 Best Gypsum Board & Drywall Suppliers in UAE
Feb 5, 2025 · Located in Mussafah, Abu Dhabi, Gypsemna operates a state-of-the-art production plant with an annual capacity of 50 million m² ... Gypsum Blocks ...
[67]
Gypsum; anhydrite exports by country |2021
In 2021, Top exporters of Gypsum; anhydrite are Oman ($131,874.88K , 9,346,730,000 Kg), Thailand ($131,025.84K , 6,537,240,000 Kg), European Union ($106,753.40 ...Missing: blocks percentage
[68]
Recent Advances in Materials, Mechanics and Structures
This book is expected to highlight the current scenario on the new and innovative technologies, materials, mechanics, and structures globally, which may help ...<|separator|>
[69]
Circularity - Eurogypsum
Plasterboard can be produced with up to 30% content of recycled gypsum coming from both production and construction and demolition waste. Recycling in ...Missing: Green blocks 2020
[70]
Europe Gypsum Market Strategic Growth & Sector Trends to 2030
Countries like Germany, the UK, and France dominate the Europe gypsum market due to their robust construction sectors and stringent environmental regulations.
[71]
Internal Partitions & Walls - British Gypsum
British Gypsum offers a full range of lightweight partition and walling systems. Standard systems are non-loadbearing and constructed using drylining ...
[72]
Gypsum Block Partition Walls - Made-in-China.com
4.1 268 · Free deliveryUpgrade your Acoustic Partition with the elegant and durable Gypsum Block Partition Walls.Acoustic partitions can be made from materials like reinforced glass, ...Missing: examples UK schools slim
[73]
(PDF) Sustainability of gypsum products as a construction material
Growth of the use of gypsum-containing wastes reduces the load in landfills. All aspects prove that gypsum products are considered to be sustainable materials.
[74]
Enhanced Water Resistance of TiO2–GO–SMS-Modified Soil ... - NIH
Sep 20, 2024 · The authors found that adding 1% SMS had minimal impact on the gypsum's strength but significantly reduced its water absorption rate from 20.63% ...<|separator|>
[75]
[PDF] Optimizing hydration and performance of phosphogypsum based ...
Mar 18, 2025 · However, the compressive strength decreased from 6.06 MPa at 1d to 2.61 MPa at 28d, indicating a. 50 % reduction due to the dissolution of PG ...
[76]
Methyl Hydrogen Silicone Fluid Improve The Water Repellent ...
Aug 14, 2020 · But when the silicone fluid additive proportion went up to 1.0%, the gypsum block's water absorption was going above 0.8%.Missing: reduction | Show results with:reduction
[77]
A comprehensive overview of fibre-reinforced gypsum-based ...
Jan 15, 2021 · The main disadvantages of gypsum are its brittleness, inferior mechanical properties, low water resistance, low thermal and sound isolation ...Missing: drawbacks | Show results with:drawbacks
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Control of Drywall Sanding Dust Exposures | NIOSH - CDC
Over time, breathing the dust from drywall joint compounds may cause persistent throat and airway irritation, coughing, phlegm production, and breathing ...Missing: block | Show results with:block
[79]
Environmental Impact of Gypsum Board Sustainability in Construction
Sep 25, 2024 · Low emissions: Gypsum production requires significantly lower calcination temperatures compared to lime and cement-based materials, leading to ...
[80]
Gypsum - Natures Way Resources
Also, metals such as lead, mercury, molybdenum, nickel, selenium in even smaller amounts may be present but well below the EPA 40 CFR Part 503 regulations.
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Gypsum Wallboard Recycling: A Reality Check - AWCI
Gypsum panel recycling presents many of the same infrastructure challenges as glass and vinyl recycling, but additional concerns and caveats also exist.Missing: block | Show results with:block