The role of chemical admixtures in the formation of the structure of cement stone

Abstract

Abstract. The influence of sulfates and carbonates of potassium and sodium on the character of the formation of the microstructure of cement stone was studied. The role of cations in the structure formation of cement stone is shown. The efficiency of chemical additives, hardening accelerators, was estimated from the ratio of the volumes of gel and capillary micropores. The ratio of gel and capillary pores allows to determine the efficiency coefficient of the action of chemical additives. It is shown that the potassium carbonate for Portland cement is the most effective additive for hardening in terms of microstructure modification, and potassium sulfate for slag Portland cement.

A Green Cement Plasticizer from Softwood Kraft Lignin

“…An earlier study articulated that K + would improve concrete formation by increasing gel porosity and decreasing capillary porosity. 22 It was reported that K + could interact with the alumina and silica in cement to improve microscopic strength in the hardened concrete. 21 Decreasing the compressive strength with further increasing OKLB2 dosages could be explained by the increased repulsion force in the cement paste.…”

“…Carboxylate ions were reported to form complexes with calcium ions on the cement surface, and remaining unadsorbed samples in the solution could enhance the interaction with cement particles during the hydration period, improving the cement compression strength. , Another reason could be the presence of potassium ions in the sample. An earlier study articulated that K + would improve concrete formation by increasing gel porosity and decreasing capillary porosity . It was reported that K + could interact with the alumina and silica in cement to improve microscopic strength in the hardened concrete …”

“…Interestingly, potassium ion was reported to interact with the active minerals of cement, such as aluminum oxide and silica, to form poly calcium potassium gypsum and feldspar, which would improve the strength of concrete . In another study, it was reported that, compared to sodium ions, potassium ions would help to decrease the formation of capillary porosity but increase the gel porosity in the concrete structure, which enhances the concrete strength . However, no study was conducted on the KOH-mediated oxidation of softwood KL to produce a plasticizer for cement pastes.…”

“…21 In another study, it was reported that, compared to sodium ions, potassium ions would help to decrease the formation of capillary porosity but increase the gel porosity in the concrete structure, which enhances the concrete strength. 22 However, no study was conducted on the KOH-mediated oxidation of softwood KL to produce a plasticizer for cement pastes.…”

Effect of mineral additives to a gypsum wet deformation

“…To improve physical and mechanical characteristics, the authors [17] modify binding substances by clay fillers. The electrolytes, especially in the form of the complex additive, provide an increase in the water impermeability [18] and strength [19] of cement composites. In [19], such an influence of potassium and sodium sulfates and carbonates is explained by the modification of the microstructure and porous structure.…”