The effect of gypsum on the hydration of C 3 S is widely studied by Menetrier et al., [7]. It has been demonstrated that the dissolution rate of C 3 S increased in the presence of gypsum. Kurdowski [8], reported that the gypsum accelerates the C 3 S hydration mainly in the pre-induction period, its effect on cement hydration takes two aspects ...
WhatsApp: +86 18221755073
Incorporation of natural gypsum (NG) to MOCP reduces its nucleation rate and growth rate, while an appropriate amount of flue gas desulfurization gypsum can provide …
WhatsApp: +86 18221755073
As the aging time increases, the size and area fraction of the μ phase initially increase, stabilizing after 2000 h of aging. Specifically, the μ phase maintains stable dimensions, with a length, width, and area fraction of approximately 1.35 μm, 0.55 μm, and 2.85 %, respectively.
WhatsApp: +86 18221755073
The results indicate that the presence of cement as an additive could eliminate the weak points of construction gypsum without any negative side effect. The study was supported by aging ...
WhatsApp: +86 18221755073
Gao, D., Z. Zhang, Y. Meng, J. Tang, and L. Yang. 2021. "Effect of flue gas desulfurization gypsum on the properties of calcium sulfoaluminate cement blended with ground granulated blast furnace slag." ... and J. Ji. 2018. "3 phase in the hydration product system of AFt-AFm-AH 3 ... Lizhe Liang, Effect of Three-Dimensional Porous ...
WhatsApp: +86 18221755073
Based on the course of the DSC curves for the gypsum, gypsum with aerogel, gypsum with polymer, and gypsum with microspheres, it was found that transitions that are characteristic for …
WhatsApp: +86 18221755073
The phase changes of gypsum were considered to be sufficiently understood for a long time. However, due to the increasing importance of gypsum recalcination (connected with the planned closure of thermal power plants resulting in a lack of FGD gypsum) and new detailed research associated with it, gaps in the current knowledge have been discovered. This paper …
WhatsApp: +86 18221755073
The synthesis of α-calcium sulfate hemihydrate (α-CSH) from flue gas desulfurization (FGD) gypsum is a good way to realize the comprehensive utilization of FGD gypsum. To obtain α-CSH with the satisfactory performances, a facile hydrothermal-aging pretreatment process for FGD gypsum raw materials was proposed, where FGD gypsum was …
WhatsApp: +86 18221755073
Houses, especially in the U.S.A. and Europe, are either built from or lined with gypsum-based products favored by architects because of their superior properties, such as obtainable availability ...
WhatsApp: +86 18221755073
Effect of Fineness of Gypsum Powder: The fine gypsum powder exhibits a greater expansion than a coarse material at a constant water-gypsum ratio. Effect of Water-gypsum ratio: Usually expansion reduces with increase in the water-gypsum ratio since the increase in the water-gypsum ratio creates more distance between the particles which will ...
WhatsApp: +86 18221755073
Engineering performance of asphalt pavement highly depends on the properties of bitumen, the bonding material to glue aggregates and fillers together. During the service period, bitumen is exposed to sunlight, oxygen and vehicle loading which in turn leads to aging and degradation. A comprehensive understanding of the aging mechanism of bitumen is of critical importance to …
WhatsApp: +86 18221755073
Section 2 provides the original experimental data on the material rheology. Section 3 describes the problem formulation for jets of the three-phase power-law fluids. Section 4 describes the invariant-based coordinate transformation used to develop the novel numerical method proposed in this work. Section 5 discusses the results for straight jets issued into the …
WhatsApp: +86 18221755073
Although low temperature aging caused the tetragonal-to-monoclinic phase transformation related to temperature, the minimum flexural strength was above 700 MPa. CONCLUSION. The monoclinic phase started to appear after aging treatment above 100℃. With the higher aging temperature, the fraction of monoclinic phase increased.
WhatsApp: +86 18221755073
Microencapsulated phase change materials (MePCMs) were fabricated via sol–gel synthesis, with nano-SiO 2 acting as shell, lauric acid (LA) and myristic acid (MA) binary eutectic mixture as core materials, and then MePCMs were incorporated in gypsum. The thermal performances of LA-MA@nano-SiO 2 MePCM as well as MePCM based gypsum board were …
WhatsApp: +86 18221755073
In this work, samples of natural gypsum from various locations of various chemical and phase compositions were studied, and the effect of a controlled amount of added crystalline modifier on the thermal properties of pure gypsum was investigated.The results of this study do not only expand knowledge about the basic mechanisms in natural gypsum ...
WhatsApp: +86 18221755073
This work investigated the effect of gypsum on the early-ages hydration progress of MOC systems by isothermal calorimetry and BNG model. The following conclusions can be …
WhatsApp: +86 18221755073
Freezing-thawing and wetting-drying accelerated aging tests are considered to simulate outdoor conditions. Two straw-gypsum plaster composites were designed. Long-term durability under …
WhatsApp: +86 18221755073
To achieve the process of making lightweight gypsum, three kinds of LWAs were selected in this paper, including pottery sand, expanded perlite and EPS particles. ... Therefore, the introduction of the gas phase under the effect of LWAs is the reason for the enhancement of sound absorption capacity. For B0-B8, it has excellent sound absorption ...
WhatsApp: +86 18221755073
Alkanolamines are commonly used complexing agents in the cement industry. Due to its surface activation effect on cement clinker particles, it is commonly used as cement grinding aids [44], [45].When used as chemical admixtures, it can accelerate the early hydration process of cement by complexing with metal ions [46], [47].Among them, triisopropanolamine (TIPA), …
WhatsApp: +86 18221755073
In this study, the impact of four accelerators, namely sodium sulfate (Na2SO4), calcium nitrite (Ca (NO2)2), triethanolamine (TEA), and diethanolisopropanolamine (DEIPA), on the hydration and...
WhatsApp: +86 18221755073
Due to the high reaction potential of cement and water, premature hydration can occur after unintentional exposure to moisture. Model binary mixtures of C3A and gypsum stored at 90% …
WhatsApp: +86 18221755073
The effects of three different curing temperatures (0°C, 20°C and 40°C) on cement setting times and performance were thus examined. ... both the CH and amorphous phase contents increased and then decreased with an increase in gypsum content. The amorphous phase content in OPC_97 + 3 was the highest among all the samples after curing at these ...
WhatsApp: +86 18221755073
The performance of composite gypsum at elevated temperatures depends on the treatment temperature and reflects the combined effects of gypsum phase change and the filler effects of silica flour or talc powder. …
WhatsApp: +86 18221755073
Results show that the mixture of desulfurization gypsum and carbide slag as skeleton material is feasible and reliable and an optimal mass ratio of desulfurization gypsum to carbide slag was obtained to be 3.5 to 1.5; the phase-change composite with the optimal mass ratio possesses good mechanical strength of up to 134.116 MPa and an energy ...
WhatsApp: +86 18221755073
Q phase is a high-alumina mineral phase belonging to the CaO-MgO-Al 2 O 3-SiO 2 quaternary system. Its chemical composition is represented by Ca 20 Al 32-2n Mg n Si n O 68, (2.5 ≤ n ≤ 3.5) [45].Q phase exhibits a low firing temperature about 1300 °C [46], and its calcium content is 33 % lower than C 3 S, indicating a reduced carbon footprint [47]. ...
WhatsApp: +86 18221755073
to be the preferred hydration phase with significant strength gain due to its good lling and interconnection properties. However, in a humid environment, 5-phase and 3-phase are easily decomposed into Mg(OH) 2, and unreacted MgO will also be converted into Mg(OH) 2, which will cause cracking and performance degradation of sample [10, 12]. To ...
WhatsApp: +86 18221755073
The effects of aging time, aging temperature, MBA addition and pH on the morphology of the synthesized CSD after hydration are investigated. 3.1.1 The effect of aging time on the synthesized crystals Figs.2(b-e) show SEM images of the synthesized crystals for different aging time under 3 g of MBA, 4 of pH, and 80 ℃ of aging temperature. With the
WhatsApp: +86 18221755073
As gypsum boards are widely used in building construction, fires leave fire patterns on the gypsum board. Currently, fire investigators identify fire patterns by visible observation or through depth measurements of materials affected by the fire [1].This analysis demands the coupling of the physical laws of fire dynamics with the investigator's inference regarding the …
WhatsApp: +86 18221755073
Request PDF | On Nov 4, 2021, Kechang Zhang and others published Improvement of the Hydration Kinetics of High Ferrite Cement: Synergic Effect of Gypsum and C 3 S–C 4 AF Systems | Find, read and ...
WhatsApp: +86 18221755073
Beyond 3 days of exposure the ettringite signal decreased, signifying carbonation and decomposition of this phase into calcite, aluminum hydroxide and gypsum as we have …
WhatsApp: +86 18221755073
Aging had a negligible effect on the insulation performance of LBR-FGP boards, while it enhanced the insulation performance of LBR-GP boards. The improvement was attributed to stress relief between gypsum crystals during dehydration and recrystallization, resulting in reduced cracking and improved insulation.
WhatsApp: +86 18221755073
The largest increase occurs in 3 days of aging at the relative humidity of 80%. The studied thermodynamic analysis of the process has showed that the most significant change of …
WhatsApp: +86 18221755073
Early on in the development phase of laboratory material, the choice of the basic components of the composite is often based on the literature and on economic considerations. ... The gypsum plaster used is a quick-setting ... the effect of accelerated aging on the thermal and mechanical properties of two plaster and cereal straw composites was ...
WhatsApp: +86 18221755073
phase can variably be altered which consequently affects the rheokinetics of the cement paste. Currently, the effect of the available amount of hemihydrate and natural gypsum in the cement sulphate phase, on both the hydration and rheology of ordinary Portland cements (OPC), are not well-understood.
WhatsApp: +86 18221755073
phase composition of gypsum (dihydrate) with the aim of producing a partially dehydrated gypsum binder similar to incompletely fired binders [12]. EXPERIMENTAL We used natural gypsum from the Baskunchak deposit (Astrakhan oblast). To reduce the effect of impurities, we selected the purest CaSO 4 · 2H 2 O samples (98.3+% purity).
WhatsApp: +86 18221755073
After 4 months of aging, C 12 A 7 and Q-phase had completely reacted, ... The degree of hydration of phases in LS and gypsum (in Fig. 3) was used to implement the hydration kinetics for a thermodynamic model. By considering the hydration kinetics in the modelling, it is possible to capture phase evolution as well as volume changes in the binder ...
WhatsApp: +86 18221755073
Although previous studies have shown that gypsum dihydrate significantly improves the grindability of GBFS compared to gypsum hemihydrate and raw gypsum [31], the effect of the phase composition of TiG on the cementitious material remains uncertain, especially considering the significant effect of drying temperature on its phase composition ...
WhatsApp: +86 18221755073
The presence of residual C 3 A can be further associated with its higher content in the original mixtures of the M1010 series, but also with the overdosed gypsum content used, which has been found ...
WhatsApp: +86 18221755073
To explore the effect of thermal aging on the phase morphology of the PI/UHMWPE blends, the intensity ratio (I 1601 /I 2885) of the peaks at 1601 cm −1 (characteristic peak of PI, indicating the benzene skeleton vibration) and 2885 cm −1 (characteristic peak of UHMWPE, indicating the –CH 2 - asymmetrical stretching vibration) was ...
WhatsApp: +86 18221755073