The effect of gypsum content on specific gravity and SSB of cements is graphically plotted in Fig. 2, Fig. 3 respectively. It seems that the obtained results were influenced by the gypsum physical properties. The decrease in cements specific gravities is mainly due to the difference between densities of clinker (3.17g/cm 3) and gypsum …
Retarding effect of gypsum for hybrid alkali-activated cements (HAACs) at ambient temperature ... The use of thermal analysis in assessing the effect of temperature on a cement paste. Cem. Concr. Res. (2005) ... known for its UV protection and antimicrobial properties has a retarder effect and can improve the materials …
Also the results indicate that cellulose fiber used in gypsum reduced the amount of deterioration of properties of fiber-reinforced gypsum (FCG) at 40 C and 200 C temperature, and the cellulosic ...
However, the effects of TG on the high-calcium FA–CCR system and the transformation rule of Fe compound in TG remain unclear. Therefore, FA–CCR and FA–natural gypsum–CCR were used as the control group. The effects of TG on the physical properties, phase composition, and microstructure of the FA–CCR system …
The best calcining temperature and influencing factors have been determined during flue gas desulphurization gypsum for calcined gypsum at different temperatures,and the performance of gypsum was tested by means of DTA,SEM-EDS and other kinds of methods.The results show that gypsum crystal grows perfectly and compactly,and …
Materials. LBM, gypsum, MgCl 2, citric acid (CA), and water are used to prepare the MOCP.The mass fraction of α-MgO in LBM is 67.6%, and it is obtained by calcining magnesite at 700–900 °C.LBM is provided by Haicheng Magnesium Minerals Co., Ltd. with a specific surface area of 1274 m 2 kg −1 and an average particle size of 14.7 …
Here, we assess the effects of gypsum and local organic waste as amendments to non-weathered, filter-pressed bauxite residue (BR) to improve its properties and support plant growth. In addition, we monitored the leachate quality of the amended BR under progressive leaching that simulated precipitation conditions in …
The main component of gypsum is calcium sulfate, and gypsum can be classified as anhydrite (CaSO 4), hemihydrate (CaSO 4 •0.5H 2 O, HH) and dihydrate gypsum (CaSO 4 •2H 2 O, DH) (Claisse and Ganjian, 2006).The HH gypsum is also called as bassanite. When the temperature is about in the 0–65 °C range, the 1.5 H 2 O …
The effects of gypsum and mulch applications on reclamation parameters and physical properties of an alkali soil Cagla Temiz & Gokhan Cayci Received: 11 December 2017 /Accepted: 4 April 2018/Published online: 17 May 2018 # Springer International Publishing AG, part of Springer Nature 2018 Abstract Alkali soils have undesirable properties for
Gypsum is one of the karstic rocks with many positive and negative characteristics. The most important defect of these rocks is solubility against water flow. The dissolution phenomenon in gypsum is accompanied by the release of the sulfate ion in water increasing its concentration, gradually. In this research, the effect of water flow …
The thermal properties of gypsum boards at elevated temperatures were described e.g. by Thomas [8] and by Park et al. [11] and thermal models were proposed by Thomas [6], Lázaro et al. [12] Weber [13] and Mehaffey et al. [14]. Gypsum exposed to high temperature exhibits significant shrinkage, which could be reduced by a suitable filler.
The reductions in the mechanical properties of gypsum plasterboard and cold-formed steel studs at elevated temperatures significantly reduce the strength and …
The effects of different dosages of gypsum on the hydration and hardening properties of AMCSA, such as setting time, hydration rate, compressive strength and hydration products, were studied. The results show that the mineral content of ye'elimite, C2S, C3S and iron phase in the calcined AMCSA clinker are 48.5 wt.%, 32.6 wt.%, 11.7 …
Luk and Darvell [8] indicated the importance of accounting for the effect of metal temperature during casting. They found that higher casting temperatures could effectively reduce the strength of PBIs by raising the investment temperature. ... Strength properties of some gypsum-bonded casting investments. Scand J Dent Res, 88 …
The property of the gypsum and its possible effect on the cement were the key considerations when choosing the quantities of gypsum. In industrial production, formula (1) is commonly used to determine the mass fraction of industrial gypsum, in which SAC with different properties has different gypsum coefficients. When M ≤ 1, the main ...
The hydrophysical properties of soil, which depend on the soil management and the soil's intrinsic textural and chemical characteristics, have a significant effect on crop growth and development. ... To prevent the loss of soluble salts, the soil samples were spread over plastic trays and air-dried in the lab at room temperature for several ...
Effect of gypsum on hydration properties, composition and kinetics of low carbon belite-ye'elimite-Q phase-ferrite clinker. Author links open overlay ... Germany). The temperature range for testing paste was 40–1000 °C, with a heating rate of 10°/min. The test samples were controlled to have a mass of 15 ± 1 mg, and the testing was ...
O= Plaster of Paris or (hemihydrate gypsum) At higher temperature (about 200ºC). Gypsum loses all its water of crystallization and changes to anhydrate gypsum as shown in Eq. (2). CaSO 4.2H 2 O ...
375 During industrial production of cement, in the cement mill, gypsum undergoes partial 0 SO 4x0.5H 2O) and in some cases total 0 SO 4) 2, 7.In order to apply the laboratory findings in industrial trial, clinker of various temperature (130-250 0C) was fed (CGF)] and filler (limestone) to produce cement (CEM I, specific surface:3500 to 3650
A mix containing fixed amounts of gypsum and ordinary portland cement clinker was ground in plant and laboratory ball mills to examine the effect of grinding in different mills on the cement properties. Mineralogical examination showed that in the plant mill (1200 cm×260 cm), because of the rising temperature during grinding, …
The calcination of phosphogypsum (PG) was employed to produce gypsum plaster to achieve its recovery and utilization. Although previous studies have indicated the possibility of producing hemihydrate and anhydrous gypsum, the influence mechanism of the impurities in calcined PG (CPG) on the properties of plaster is unclear. Herein, the …
This paper studies the different calcination temperature on the properties of titanium gypsum physical effects, and the mechanism of the effects are discussed in this paper. Research has shown that with the increase of calcination temperature, the mechanical properties of titanium gypsum present a trend of after rising first down. When the …
The effect of utilization of natural anhydrite gypsum type instead of natural gypsum rock on the properties of cement paste prepared from CEMI and CEMII cements was investigated by Tzouvalas et al. [17]. It was shown that natural anhydrite could efficiently retard the setting of cement with no significant change in the physico …
In this study, eight mesoscale LWF walls were tested to determine the effects of an innovative gypsum-particle composite …
b = Gypsum Backing Board and Gypsum Coreboard c = Water‐Resistant Gypsum Backing Board d = Exterior Gypsum Soffit Board e = Gypsum Sheathing Board f = Gypsum Base for Veneer Plaster g = Gypsum Lath h = Gypsum Ceiling Board 2 SeeASTMC473fora descriptionofMethods AandB
Clinker is formed after firing a raw mill of limestone and clay at around 1450 °C, ... The effect of gypsum content on properties of anhydrous cements, cement pastes and mortars was studied using various contents of gypsum. ... But for high-temperature reservoirs (>150 °C), it is advisable to use multiple retarders.
The thermal conductivity, specific heat, mass loss, and linear contraction for gypsum board types widely used in the USA and Japan were measured both at room temperature and …
The present paper describes the results of an effort to quantify thermal properties of gypsum board. The thermal conductivity specific heat mass loss and …
Recent research has focused on investigating the influence of plastic waste on the properties of gypsum-based materials, including the quality of the …
As a first approach to evaluate the effect of high temperature on the microstructure nature of gypsum/cement binder matrix, Yu and Brouwers [18] analyzed the phases of hardened gypsum matrix's dehydration procedure by heating it to 1000 °C. It was found the microstructure of the gypsum matrix considerably changed beyond …
their beliefs and experiences, claiming an effect in the same growing season or soon after gypsum application (Brock et al., 2020). The application of gypsum to soils is known to provide physical and chemical benefits. Norton and Rhoton (2007) proposed that gypsum improves soil tilth, and similar claims regarding positive effects on soil tilth ...
