Peculiarities of Nanomodified Portland Systems Structure Formation

Abstract

Regulation of hydration processes on nanostructure scale due to the competition adsorption modifying of hydration products by polycarboxylate and adding of nanosized C-S-H nuclei allows promoting homogeneous distribution of solid phase in the structure of cement paste on the micro-and nanolevel, provides the growth of contact amount between hydrates, results rapid structure formation and strength synthesis of Portland cement system.

Composite Materials Based on Phosphogypsum for Constructive Layers of Road Pavement

“…As can be seen from the diffractograms, the mechanism of interaction between the components of the "phosphogypsum-granulated blast furnace slag-Portland cement" systems does not change with an increase in the phosphogypsum content, and the phase composition of the products of the interaction products indicates alkalinesulfate activation of the slag. [27][28][29][30][31] The phase composition of composite materials (cementitious substance 2) after 28 days is represented by gypsum (d/n= 0.756; 0.429; 0.308; 0.287; 0.268 nm), as well as products of hydration of the components of composite mixtures and interaction between them calcium hydrosilicates (tobermorite (d/n= 1.103; 0.550; 0.308; 0.281 nm), jennite (d/n= 1.050; 0.477; 0.347; 0.329; 0.304; 0.266 nm), ettringite (d/n= 0.973; 0.561; 0.388; 0.348; 0.256 nm) and portlandite (d/n= d/n=0.497; 0.263; 0.193; 0.179 nm)). The formation of hydrosulfoaluminate in the cementitious component due to sulfate activation contributes to the reinforcement of the system at the initial stage of interaction, breaking the gel film on the slag grains, diffusion of SO 4 2-, Ca 2+ and OHions into the grains and to prolong the hydration reaction and accelerate the strength gain.…”

Analysis of air jets velocity attenuation at special initial conditions

“…Microclimate of premise should be also improved due to energy saving measures of heat source [39], building walls [40,41], heating system [42 -44], ventilation system [45] and gas and heat supply systems [46,47]. It is advisable to use also exhaust air heat and recuperation [48,49] for energy saving.…”

Optimization of Hydrolysis in Ethanol Production from Bamboo

“…The introduction of technologies for the gas emissions treatment, 1,2 monitoring of the hydrosphere 3,4 and the widespread introduction of technologies for wastewater treatment 5,6 should be noted, but the introduction of technologies for solid industrial and household waste should be of particular importance, in particular their involvement as raw materials in energy, 7 industrial, 8 agricultural 9,10 technologies and in the building materials industry. 11,12 Therefore, at the end of the last century the cement-ash mixtures (CAM) have begun to be widely introduced at the drilling plants of Ukraine. Acid fly ash, which is obtained after coal combustion at Kurakhiv, Ladyzhyn, Burshtyn and Dobrotvorsk state district power plants (SDPP), serves as an active aluminosilicate additive to Portland cement.…”