· Proper modification is a possibility how to eliminate gypsum negative properties and how to contribute to a wider utilization of gypsum even in exterior applications. The second effect of modifications lies is improving of hardened gypsum properties (e.g. mechanical properties, lower volume density and thermal properties).

 · Compressive strength of gypsum was determined on the halves of the specimens prisms with dimensions 16 × 4 × 4 cm after 2 h of hardening, made of high-strength mixtures of separated gypsum brand G-16 A III, the water demand of 37–40% (CJSC "Samara plaster plant", Russia) with the low multiplicity s (4–6) and without …

 · That is why gypsum is used in winter in arid and semi-arid regions when there is access to good amount of water. To be suitable for soil amendment, gypsum must have these properties: – Its salinity must be less than 3dS/m (the salinity of pure gypsum solution is about 2.5 dS/m).

 · Gypsum, a hydrated calcium sulfate, is a mineral that occurs in large deposits throughout the world. Gypsum is applied to the soil as a source of calcium and sulfur. …

 · Building gypsum has the following properties: Fast setting and hardening Building gypsum has fast setting and hardening speed. Usually, it achieves the initial …

the gypsum hollow block integral wall has superior fire performance, because the gypsum itself has its own unique molecular structure caso4.2h2o contains crystal water,(containing 20% water;crystal water and free water), in case of fire, the wall can evaporate about 10kg of water per square meter before it can produce a large temperature rise.in …

 · Physical and mechanical properties of gypsum stone Full size table When using based on Penostrom, the average density of gypsum stone is reduced from 1320 to 430 kg/m 3, the thermal conductivity coefficient from 0.57 to 0.14 W/ (m∙°C) (by 4 times), the compressive strength from 14.6 to 2.4 MPa (by 6 times).

The physical properties that distinguish gypsum from other minerals are: Gypsum ranges from transparent to translucent. Gypsum comes in varieties such as "satin spar" and "alabaster." The mineral is soft and feels rather light Small crystal-like forms appear pearly, whereas the massive ones look dull. Important uses of Gypsum

 · Rheology of paste is improved when gypsum is replaced by the other salts, due to less hydration and less crystals of acicular shape. For in particular calcium nitrate the cumulative hydration energy is reduced under isothermal conditions, which opens up for low-energy cement without changing clinker chemistry.

 · Gypsum is first crushed, heat-dried and then powdered. 1. Gypsum is used as fertilizer. 2. Gypsum prevents soil erosion, improves soil composition, helps the movement of water and air, and facilitates root growth. 3. Gypsum balances micronutrients like zinc, iron etc. 4. Gypsum powder is also used in making drywalls. 5.

 · Gypsum is the mineral that includes in its structure Sulfate ion, which makes it a sulfate mineral, and of all the sulfate minerals, Gypsum is the most common. Gypsum is …

 · The gypsum also possesses good thermal properties due to which it provides a good balance between indoor humidity and temperature. The use of the plasterboards in the interior of the structures acts as a vapor barrier that prevents humidity in the indoor of the building.. 2. Gypsum Boards Are Fire Resistant in Nature. Gypsum boards are fire …

gypsum, common sulfate mineral of great commercial importance, composed of hydrated calcium sulfate (CaSO 4 ·2H 2 O). In well-developed crystals the mineral commonly has been called selenite. The fibrous massive variety has a silky lustre and is called satin spar; it is translucent and opalescent and is valued for ornaments and jewelry.

Model plaster: Model gypsum can be used in foundry, art, ceramics and other industries. 3. Agriculture: It can be used to produce sulfuric acid and ammonium sulfate fertilizer. …

 · – These properties are: 1. Accuracy 2. Dimensional stability 3. Ability to reproduce fine detail 4. Strength and resistance to abrasion 5. Compatibility with the impression material 6. Color 7. Biological safety 8. …

 · The monolithic gypsum samples used in this study were prepared by hydration of a gypsum board stucco (CaSO 4 ·0.5H 2 O (β-hemihydrate) powder produced at USG's Southard, OK plant) with and without the addition of an accelerator (ground gypsum supplied by USG). The starting powder was mixed with water (20 °C) and cast into split cubic …

THERMAL AND MECHANICAL PROPERTIES OF GYPSUM BOARDS AND THEIR INFLUENCES ON FIRE RESISTANCE OF GYPSUM BOARD BASED SYSTEMS A thesis submitted to the University of Manchester for the degree of Doctor of Philosophy in the Faculty of Engineering and Physical Sciences 2011 IMA RAHMANIAN School of …

 · PHYSICAL PROPERTIES OF SALT, AMHYDRITE, MD GYPSUM ^y-Eugene. C. Robertson, Richard A, Robie, " and Kenneth G. Books ABSTRACT This summary is the yesult of a search of the available literattire. Bxrphasis is placed on the mechanical and calorimetric properties of saltj the measurements of elastic, thermal, magnetic, and mass …

 · The general properties of gypsum plaster are as follows, 1. The gypsum plaster is very light-weight compared to conventional cement plaster and therefore the usage of …

gypsum, common sulfate mineral of great commercial importance, composed of hydrated calcium sulfate (CaSO4·2H2O). In well-developed crystals the mineral commonly has been called selenite. The fibrous massive variety has a silky lustre and is called satin spar; it is translucent and opalescent and is valued for ornaments and jewelry. The fine-grained …

★ Gypsum is used in making surgical and orthopedic casts, such as surgical splints and casting molds. ★ Gypsum plays an important role in agriculture as a soil additive, conditioner, and fertilizer. It helps loosen up compact …

 · Gypsum board assemblies are now widely used in buildings, as fire resistant walls or ceilings, to provide passive fire protection. The fire resistance of such systems is fundamentally due to the desirable thermal properties of gypsum. Yet there is wide variability in reported values of thermal properties of gypsum at high temperatures and a lack of …

 · The flexural strength of gypsum is reported for freestanding single crystals in three-point bending carried with a nanoindenter. The elastic modulus, splitting tensile strength, and fracture toughness of monolithic gypsum consisting of interlocking needle-like microcrystals are also reported as functions of porosity and accelerator addition.

 · The microcapsules achieved a high encapsulation efficiency of about 83.9% through pH regulation. • Gypsum containing 10 wt% of the microcapsule exhibited a high thermal conductivity of more than 0.3 W/ (m·K). • Obvious thermal regulation performance of the gypsum materials when the microcapsules was incorporated. c specific heat capacity T

 · Gypsum is a very soft mineral that is easily identified by its hardness, cleavage, and solubility in water. Typically clear to white, gypsum may be colored reddish to brown or yellow if impurities are present. Most gypsum occurs in its massive form, as layers of rock that often intercalate layers of shale, limestone, or dolostone.

 · A porous gypsum is an important sound-absorbing material while dense and hard plasters are efficient reflectors of sound up to 90% energy incident at their surfaces. i. It has high tensile and flexural strength. j. It prevents rusting of metal by increasing its durability. k. It has low thermal conductivity. 9. Uses of Gypsum Plaster

Physical Properties of Gypsum: Chemical Classification: Sulfate: Color: Clear, colorless, white, gray, yellow, red, brown: Streak: White: Luster: …

 · Properties of Gypsum 1. Fire Resistance Gypsum has fire-like properties. Which provides protection to the customer's property from fire for any reason. 2. Thermal Properties Gypsum is capable of stabilizing conditions such …

 · The fire resistance of such systems is fundamentally due to the desirable thermal properties of gypsum. Yet there is wide variability in reported values of thermal properties of gypsum at high temperatures and a lack of understanding of its integrity in fire.

 · Gypsum has the property of balancing humidity as well as indoor climate. In addition, it helps maintain the temperature inside the building. Gypsum is very useful due …

Abstract— The paper presents time dependent changes of mechanical properties (Young's Modulus, strength and creep ) of grey calcined gypsum. These material properties were measured in different time instants during hardening on the gypsum specimens of dimensions 40 x 40 x 160 mm using nondestructive and destructive methods. For the …