Water-resistant fiber-reinforced gypsum cement-pozzolanic composites

Abstract

Gypsum and gypsum-cement-pozzolanic composites are of significant interest as materials and products for building decoration. The current tendency to reduce the consumption of gypsum-based materials and products in the context of growth and development of the finishing materials market depends on the decrease in their competitiveness compared to peers. This leads to significant interest in improving the quality of products based on gypsum and gypsum-cement-pozzolanic binder. Dispersed reinforcement is one of the ways of improving performance characteristics. The role of the type of reinforcing fibers in the formation of the gypsum-cement-pozzolanic composites structure and properties is studied in article. The influence relations of the cellulose fibers content with varying grinding degrees on the relative flexural and compressive strength of a gypsum-cement-pozzolanic matrix are obtained. It was found that the optimal content of cellulose fibers in the modified gypsum-cement-pozzolanic matrix is 0.5-1% by weight of the binder, the best indicators of flexural and compressive strength are achieved by grinding cellulose fibers to 30°SR. Using scanning electron microscopy, it was found that the microstructure of a disperse-reinforced gypsum-cementpozzolanic matrix is characterized by a uniform cellulose fibers distribution, the predominance of directionally frame reinforcement with a fibers linear orientation in the sheet plane. In this way the right choice of the type, crushing degree and cellulose fibers content can improve the quality and expand the application area of the produced gypsum-cementpozzolanic composites.

High-strength gypsum binder with improved water-resistance coefficient derived from industrial wastes

“…Such a composition was called gypsum-cement-pozzolanic binders (Magallanes-Rivera et al, 2012; Volzhensky et al, 1969;Çolak, 2002). Studies have shown that the most stable composition consists of a gypsum binder, Portland cement, and an appropriate amount of active mineral additives, which is called gypsumcement-pozzolanic binders (Mukhametrakhimov et al, 2019;Potapova et al, 2020).…”

Gypsum Composite Reinforced with Polymer Fibers

“…It is possible to increase water resistance of gypsum binder in various ways [14][15][16][17][18][19][20]. The simplest and, at the same time, effective, is creation of mixed gypsum binders.…”

The influence of complex additives based on calcined clays and carbonate fillers on hydration products composition of blended cement stone

“…Therefore, recently, scientists have been working on the search for effective pozzolanic materials from thermally activated polymineral clays with a low content of kaolinite and its complete absence [4][5][6]. At the same time, it was found that the combined use of polymineral clays with carbonate additives leads to the emergence of a synergistic effect, expressed in an increase in technical and operational parameters of obtained materials [7][8][9][10][11][12][13][14][15]. Complex additives which differ by presence of a synergetic effect in the cointroduction of multiple mineral additives are of great importance while the creation of blended cements [1][2][3][4][5][6][7].…”

“…XRD pattern of blended cement stone sample with 20 % of complex additive based on calcined kaolinitic clay and limestone.The diffractogram indicates a large presence of carboaluminate phases. There is a complete transition of calcium hydromonosulfoaluminate (3CaO • Al2O3 • CaSO4 • (11-12) H2O) in Portland cement on the CaCO3 particles surface into calcium hydromonocarboaluminates (3CaO • Al2O3 • CaCO3 • (11-12) H2O)[12] with interplanar distances d = (4.267; 4.167; 3.661; 3.521; 3.117; 2.653) Å[10]. It should be noted that the limestone amount and its activity are sufficient for the entire hydrosemicarboaluminate (3СаО • Al2O3 • 0.5CaСO3 • (11-12) H2O) to turn into calcium hydrogen monocarboaluminate[11].In the composition of the blended cement stone with the complex additive, there is a small content of ettringite (d = (9.718; 5.646) • Å), approximately the same as in the control composition.…”