Influence of different water types on the physical and mechanical properties of gypsum (original) (raw)
Related papers
International Journal of Applied Dental Sciences, 2019
The aim of this in vitro study was to evaluate the effect of three liquid types including tap water, distilled water and slurry water on surface hardness of type IV gypsum (GC Fuji Rock, Japan). For each studied groups, 10 dies were produced according to the manufacturer’s instructions whereby gypsum powder were mixed with three different liquids. Twenty four hours after producing the dies, hardness measurement test was carried out by way of micro Vickers and using the set (MATSUZAVA, MHT2, Japan) and penetration time of 5 sec and power of 25 g. The test was carried out on three points of each die’s surface and averages of hardness of dies were measured. The obtained data were evaluated by using of one-way ANOVA test as well as Tukey test using SPSS program. Results showed that the average of surface hardness between the three studied groups, have significant statistical differences with each other (p<0.001). In the range of this study, it was shown that distilled water and slurr...
Effect of mineral additives to a gypsum wet deformation
E3S Web of Conferences, 2021
The influence of mineral additive, i.e. ground granulated blast-furnace slag on artificial gypsum stone humidity strains has been studied. The slag content was varied in the range from 0 to 0.33 by weight based on the total amount of the mixture. The measurements were carried out on prism samples with dimensions of 160x40x40 mm. The samples were placed vertically in containers with water, the deformations were measured using dial indicators. It was established that the humidity strain value depends on the content of the granulated milled blastfurnace slag. A maximum strain of over 0.001 m/m is observed for the gypsum stone without mineral additive. A relative strain is decreased with an increase in the slag content. Minimum humidity strain of 0.0003-0.0004 m/m was observed for the artificial gypsum stone with the relative slag content of 0.05-0.1 and more than 0.27. This fact confirms our assumption that the water concentrated in the contacts between the individual crystals and part...
Effect of Adding Industrial Wastes on the Mechanical Properties of Gypsum
2019
Abstract: In this research an attempt has been made to study the effect of adding P.V.C (by weight) on gypsum properties (compressive strength, modules of rapture). The research plan consists of using eight different percentage of waste material (P.V.C) (0, 1, 2, 3, 4, 5, 6 and 7)% (by weight as addition) and (water/gypsum) ratio equal to 32 % . The results of this study show that the local waste material PVC can be used with construction materials such as gypsum safely and the PVC enhancing the mechanical properties (compressive strength and modulus of rupture) when it used the optimum ratio 3% .
Eastern-European Journal of Enterprise Technologies, 2021
This paper reports a study into the effect of mineral fillers such as ground granulated blast furnace slag, microsilica, and nano dispersed alumina on the structure formation and water resistance of gypsum. The theoretical models of gypsum stone structure with mineral fillers have been built and described, taking into consideration the sign of the surface charge of gypsum crystals and filler particles. In accordance with the developed models, the fillers enable the formation of a dense structure of gypsum stone as a compositional material with a large number of electro-heterogeneous contacts. With this structure, the gypsum dihydrate crystals are maximally protected from contact with water and dissolution. The electron microscopic study of the gypsum stone with mineral fillers has been carried out, which has confirmed that the rational ratio of gypsum to slag ensures the densest structure of the stone. The dependences of the strength of gypsum stone in the dry and water-saturated co...
Improvement of Gypsum Properties Using S . F . Additive
2017
In this research an attempt has been made to study the effect of adding S.F. additive (by weight) to improve gypsum properties (compressive strength, bulk density, and porosity). The research plan consists of using nine mixes of gypsum which had been divided in to three groups according to S.F. content (by weight) 0.0%, 0.6% and 1.2%. Each group was divided in to three sub-groups according to (water/gypsum) ratios (0.3, 0.35 and 0.4). It was found that, the addition of S.F. to the gypsum mixes, increases the compressive strength and bulk density, but deceases the porosity. It was also found that, the compressive strength and bulk density were decreased with the increase of (water/gypsum) ratios, whereas, the porosity increases.
Influence of pH liquid for mixing gypsum binders on the strength of gypsum composites
MATEC Web of Conferences
The influence of fluid acidity on the processes of hardness, mechanism, kinetics, properties of gypsum stone are of great interest.Studies of these processes for modified composites based on gypsum and heavy high density and basalt additives can improve the modifier's effectiveness. The influence of the pH of a liquid on the processes of structure formation and the properties of composites is determined in this work. It is shown that the pH should be shared by other structure-forming factors. This is the chemical composition of basalt waste, its percentage, the interaction of its oxides with pore fluid and natural minerals are the products of their reaction. The regulation of the material composition of composites can enhance the properties and also lead to degradation of structures.
The Effect of Different Water Types on The Water Powder Ratio of Dental Gypsum Products
Al-Rafidain Dental Journal
Aims: To evaluate the effect of different water types on the water powder ratio of dental gypsum products. Materials and Methods: In this study five types of water (distilled, tab, slurry, de-ionized and well water) were used to be mixed with two types of dental gypsum products (plaster and stone). Results: Results showed a statistically significant difference at p ≤ 0.05 in water powder ratio of gypsum products when mixed with different types of water that used in this study. Conclusions: Water requirement of gypsum product varies in respect to the type of water used to be mixed with. The most pronounce decrease in water requirement of dental gypsum products was achieved with slurry water.
An evaluation of the compression strength of gypsum according to proportion and manipulation
Brazilian Dental Science, 2010
This study evaluated the compression strength of gypsum type IV and V according to 2 variables: 1) water proportioned randomly or as recommended by the manufacturer and 2) according to 3 (three) different groups of operators (dentists, technicians and dental students). 180 specimens, produced according to ADA regulation nr. 25 underwent, after seven days (dry resistance), the compression strength test in an universal testing machine. After statistical analyses of the data, there was no statistical significant difference regarding the group of operators. Regarding the variable proportion, the specimens manufactured using a random proportion of water/gypsum powder presented a lower compression value (626,2 Kgf/cm2) when compared to the group where the amount of water/gypsum powder followed the recommendation of the manufacturer (741,7 Kgf/cm2). This difference was statistically significant (p<0.01).