Changes in the Strength Properties and Phase Transition of Gypsum Modified with Microspheres, Aerogel and HEMC Polymer

Abstract

The paper presents an assessment of the impact of using additives on the strength of a binding material, i.e., building gypsum, and also the phase transformation that takes place in it. Microspheres, aerogel and polymer (HEMC) additives were added to a building gypsum slurry with a water to gypsum ratio of 0.75. In order to investigate their influence on bending strength, compressive strength, and the effect of high temperatures, differential scanning calorimetry (DSC), as well as tests of the multicomponent binder, were carried out in accordance with the applicable PN-EN 13279-2:2005 standard. The obtained test results allowed to determine that the used additives influenced the strength parameters of the obtained composites. It was shown that the applied additives decreased the compressive and bending strength of the modified gypsum. Despite these properties, the obtained gypsum materials are environmentally friendly because they reuse wastes, such as microspheres. Out of all the applied additives, the use of microspheres in an amount of 10% caused a decrease in the bending strength by only 10%, and an increase in the compressive strength by 4%.

Fracture Behavior of Long Fiber Reinforced Geopolymer Composites at Different Operating Temperatures

“…The decrease in mechanical properties at high temperatures was explained by temperature-induced thermal deformations and mass loss [38]. At the microstructural level, it was associated with water loss and deterioration bonding between the aggregate and the matrix, but this behavior was observed at significantly higher temperatures, such as 400 • C, 600 • C, and 800 • C [39][40][41][42]. This behavior cannot be explained by the loss of the properties of the fibers used because all of them are resistant to much higher temperatures.…”

Macroencapsulation of Paraffin in a Polymer–Gypsum Composite Using Granulation Technique

“…For comparison, gypsum with paraffin had a reduction in compression of 4.2% and a bending reduction of 9.4%. Another interesting study [ 38 ] was the investigation of gypsum with various admixtures. The following elements were added to the gypsum: microspheres, which are products of coal combustion; aerogel, which is characterized by a low thermal conductivity coefficient; and a polymer characterized by water resistance, widely used in construction.…”

Modifying Geopolymer Wettability by Plasma Treatment and Fly Ash

“…Materials usable to reinforce geopolymers (and other materials) include carbon, basalt, steel, microspheres, various polymers etc. Geopolymers may also be reinforced with biological materials, such as flax or hemp fibers., or waste materials (such as glass wool) [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] Plasma, an ionized gas exhibiting kvasineutrality and colletive behavior, is used for cleaning, etching and activation of surfaces, thin layer formation and other purposes. Unlike other methods, it doesn't require high temperatures and agressive or toxic chemicals (solvents or catalysts), and can therefore be used for less durable materials or in medicine.…”