Influence of high-temperature exposure on the properties of gypsum …
1. Introduction. Gypsum plasters are widely used as a coating material in the construction sector to offer structural components passive protection against fire, due to gypsum's non-combustibility property [1].When gypsum dehydrates to produce bassanite (CaSO 4 ·1/2H 2 O) and finally, anhydrite (CaSO 4) at higher temperatures, it absorbs …
Understanding gypsum in 3 diagrams
At higher temperatures the super-saturation is lower and the expected reaction speed is lower. However, as the ions can move faster at higher temperature, …
Influence of the Calcination Temperature of Synthetic Gypsum …
The paper assesses the influence of the calcination temperature of synthetic gypsum binder on the binding properties of innovative gypsum pastes, as well as on masonry and plastering mortars. The calcination process of gypsum binder was carried out at four different temperatures ranging from 170 to 190 °C. The specimens for testing …
How might edaphic specialists in gypsum islands respond to climate …
Background and Aims Local adaptation and phenotypic plasticity are considered key mechanisms for coping with climate warming, especially for plant species that inhabit island-like habitats. In Spain a complete guild of edaphic specialists, most of them threatened, occurs in gypsum outcrops, but how these species will respond to climate …
Phase- and morphology-controlled crystallization of gypsum …
Fig. 1 shows the XRD pattern of FGD gypsum raw materials, which indicates that the main phase of FGD gypsum is calcium sulfate dihydrate. The morphology of FGD gypsum is given in Fig. 2.As illustrated in Fig. 2 a, the FGD gypsum has large particles with an average particle size distribution of about 60 μm. Fig. 2 b clearly reveals that …
Gypsum Mineral | Uses and Properties
Gypsum is an evaporite mineral most commonly found in layered sedimentary deposits in association with halite, anhydrite, sulfur, calcite, and dolomite. Gypsum (CaSO 4. 2H 2 O) is very similar to Anhydrite …
Enhancing sustainability with waste hemp-shive and phase change …
Therefore, using phase change materials with lower or higher melting points based on other weather conditions should be considered a subject for future research in gypsum-based composites. Additionally, the impact of using the mentioned PCM composites on cost-saving and CO 2 emission reduction values should be investigated …
Gypsum, CO Weather Conditions | Weather Underground
Gypsum Weather Forecasts. Weather Underground provides local & long-range weather forecasts, weatherreports, maps & tropical weather conditions for the Gypsum area. ... Change : : . access_time 1: ...
Causes and consequences of the Messinian salinity crisis
Overall, it seems that the long-term evolution from pre-evaporitic marls to gypsum and salt deposition was not driven predominantly by Mediterranean climate change, and that relative sea-level ...
High-Temperature Phase Change Materials (PCM) …
electrical power plants at a temperature range from 300°C to 500°C. The physical properties most relevant for PCMs service were reviewed from the candidate selection list. Some of the PCM candidates were characterized for: chemical stability with some container materials; phase change transformation temperatures; and latent heats.
Preparation and characterization of phase change energy storage gypsum
In order to obtain suitable phase change materials (PCMs) and phase transition temperature for energy storage in the field of construction, a series of organic composite phase change materials ...
Retarding effect of gypsum for hybrid alkali-activated …
On the other hand, the gypsum may cause changes in the ion dissolution rate, thus prolonging or shortening the setting time of hybrid alkaline cement. Hence the veritable mechanism that gypsum influences the setting of HAACs needs to be determined via the following calorimetric analysis and microscopic analysis such as XRD, TGA and …
Effect of high temperatures on gypsum-based composites
Gypsum-based pastes and mortars were exposed to the temperatures up to 1000 °C. • Volume changes of mortars were three times smaller than volume changes of pastes. • Pure gypsum demonstrated the higher residual compressive strength at 1000 °C. • Gypsum-lime material featured the least favourable behaviour at high temperatures. •
MEASUREMENT OF THERMAL PROPERTIES OF GYPSUM …
Since temperature changes in the probe are strongly dependent on sample composition, it is possible to evaluate the thermal transport properties of materials surrounding the probe. ... temperature for the gypsum board samples. Triplicate samples of …
How might edaphic specialists in gypsum islands respond to climate …
Background and aims: Local adaptation and phenotypic plasticity are considered key mechanisms for coping with climate warming, especially for plant species that inhabit island-like habitats. In Spain a complete guild of edaphic specialists, most of them threatened, occurs in gypsum outcrops, but how these species will respond to …
TEMPERATURE & HUMIDITY WHILE HANGING AND FINISHING DRYWALL …
The relative humidity of a volume of air changes as the temperature changes. The absolute humidity of that volume of air does not. ... -For mechanical installation of gypsum board, room temperature should be maintained at not less than 40oF (5oC). - not less than 50oF (10oC) for adhesive application of gypsum board and …
Does Drywall Crack in Cold Weather: 4 Reasons [Explained]
When temperatures dip below 40ºF (5ºC), drywall can become vulnerable to cracking due to its gypsum core expanding and contracting with changes in temperature. Protecting the walls from these fluctuations is key, or else they could start showing unsightly cracks along seams or corners. Prepare your walls for winter with some simple ...
Effect of high temperatures on gypsum-based composites
Gypsum exposed to high temperature exhibits significant shrinkage, which could be reduced by a suitable filler. Vermiculite is commonly used as an additive to mitigate shrinkage at high temperatures in commercial products, but vermiculite significantly decreases the mechanical properties of gypsum. ... The volume changes …
Geochemical modeling of CO2 injection and gypsum …
The gypsum precipitation is calculated as a function of CO 2 concentration (CO 2 partial pressure of 20–100 bar), reservoir temperature (20–40 °C), and pressure (70–100 bar) to identify the changes in brine composition and the potential formation of the calcium sulfate minerals.
Preparation and heat storage/release behavior of latent heat …
The hardened gypsum–composite material exhibits some defects in the interface between the phase-change composite and the gypsum, but these do not seriously affect the strength of the gypsum product. The results of a temperature cycle test illustrate that gypsum containing 5 % phase-change composite can deliver high …
Gypsum | Properties, Formation, Uses and Deposits
Alteration: Over geological time, gypsum may undergo alteration processes, such as hydration and dehydration, depending on changes in temperature, pressure, and the presence of other minerals. These processes can lead to the conversion of gypsum into anhydrite or other minerals.
Solubility Measurements and Predictions of Gypsum, …
Today's oil and gas production from deep reservoirs permits exploitation of more oil and gas reserves but increases risks due to conditions of high temperature and high pressure. Predicting mineral solubility under such extreme conditions is critical for mitigating scaling risks, a common and costly problem. Solubility predictions use …
Long-term effects of gypsum on the chemistry of sodic soils
Soils with high exchangeable sodium contents have structural and hydrological problems that limit agricultural productivity. Gypsum is commonly applied as an ameliorant but there are few field studies into its long-term (> 10 years) effects on soil chemistry, especially at depths greater than 0.4 m, and no long-term validation of the …
Thermal behaviour of a gypsum board incorporated with phase change
The temperature is set below the phase change temperature of the PCM to avoid melting of the PCM. When making gypsum board without PCM, the temperature of the climate chamber is set to be 50 °C for a quicker drying. Download: Download high-res image (266KB) Download: Download full-size image; Fig. 1.
Changing pH in Soil
It also changes fertilizers from their form in the bag to a form that plants can easily uptake. Soil microorganisms that change organic nitrogen (amino acids) to ... Pure Gypsum 1 Ton of Soil Sulfur Gypsum CaSO4 ٠ 2H2O 1.00 5.38 Soil sulfur S 0.19 1.00 Sulfuric acid (conc.) H2SO4 0.61 3.20
Late Glacial temperature and precipitation changes in the …
The last deglaciation between ∼19 and 10 ka was a time of major reorganization of Earth's climate system, yet little is known about the magnitude and temporal pattern of temperature change in the tropics. The gypsum–calcite δ 18 O record from Petén Itzá provides a temperature history for the last deglaciation in the lowland …
Influence of calcination temperature on hydration behavior, …
Research related to traditional multiphase gypsum has mainly focused on the mineralogical and textural characterization of historic mortars and plasters [6], [10], [11], [12], [13].There is, however, a lack of systematic studies which correlate the properties of the set plaster (i.e., mechanical strength and weathering resistance) with the calcination …
Analysis of drying and saturating natural gypsum samples for mechanical
The particle density of natural gypsum samples before and after drying in an oven for different periods is shown in Table 2.Before oven heating, samples had a particle density (ρ s) of around 2.3 g/cm 3, which is the average particle density for gypsum.The exception is rock block 8, i.e. samples #8 dry and #8 powdered (crushed sample), which …
Development of gypsum plasterboard embodied with …
Temperature of mPCM-gypsum plasterboard and gypsum plasterboard. ... Performance evaluation of dual phase change material gypsum board for the reduction of temperature swings in a building prototype in composite climate. Energy Build., 159 (2018), pp. 191-200, 10.1016/j.enbuild.2017.10.097.
Behavior of calcium sulfate at high temperatures
tify a transition and fix its temperature. Masuda [5] reported that this transition occurred at 1,232° C, and unpublished data obtained by the writer indicated that the transition took place at an inter mediate temperature. Because of the large variation in the reported temperature of transition, it was decided to report these data to