Effect of an Aluminosilicate Disperse Additive on Behaviors of Autoclave Silicate Materials

Abstract

In this research, a phase formation in CaO–SiO2–Al2O3–H2O binding system under hydrothermal conditions was studied. The novelty of this article lies in the quantitative full-profile X-ray diffraction (XRD) analysis used to determine kinetics of mineral formation in the binder system “lime–granite mineral modifier (GMM)”. The formation of a polymineral system is described in detail, as well as quantitative relationships between mineral composition of newly formed phases and the binding mixture ratios were determined. Phenomenological model of mineral formation in a “lime–GMM” system under hydrothermal conditions was proposed. The results obtained allow the demonstration of this binding system as a binder that is characterized by superposition of hydration and geopolymerization. The properties (strength, density, water absorption, porosity) of compressed autoclave-hardened materials with the addition of a granite modifier introduced instead of part of the sand as an aggregate have been studied. The maximum increase in strength (more than 50%) is observed at a modifier content of 15%. This is due to the formation of a rational composition of neoplasms, the compaction of the structure of the pressed products and the optimization of their pore space, which is confirmed by the data of X-ray diffraction analysis, scanning electron microscopy and the method of gas adsorption.

Assessment of Pozzolanic Activity of Ground Scoria Rocks under Low- and High-Pressure (Autoclave) Steam Curing

“…Albite-anorthite groups of minerals are known as unstable minerals under hydrothermal conditions, which dissociate in the presence of Portlandite into CASH, while diopside and enstatite are more stable under such conditions [1]. The reaction of albite with lime under autoclave conditions is reported to lead to the formation of CASH gel compositions (wairakite), while that of quartz leads to the formation of tobermorite [20]. FTIR analysis in Figure 6 shows the presence of different absorption bands at 3441 cm −1 , O-H stretching, and 1640 cm −1 for O-H bending, attributed to the humidity in the sample.…”

“…One of these procedures, autoclave curing, or high-pressure steam curing, allows for the rapid production of precast concrete for a variety of immediate applications [16][17][18][19]. The enhanced properties are attributed to the improved microstructure and decreased pore system with maximum refinement [20]. Precast and normal concrete technology will benefit from this study.…”

Effects of Admixtures on Energy Consumption in the Process of Ready-Mixed Concrete Mixing

“…All raw materials were stored in different storage locations in the RMC plant, as shown in Figures 1 and 2, and when the mixing operation began, they were transported to the mixing chamber by a conveyor. Two types of high-efficiency water-reducing agents were used: PCE-based (Polycarboxylic ethers), a medium-range water-reducing agent, and SNF-based (Sulfonated naphthalene formaldehyde), a high-range water-reducing agent [37][38][39][40].…”