Study of change in the deformation-strength properties of nanomodified fine-grained concretes over time

Self Cite

48 concentrates, is of significant scientific and practical interest, and resolving it is a relevant task. 2. Literature review and problem statement Concrete, according to [1], represents the poly-structural system "matrix-filler-their interface", in which cement stone is the matrix. At the same time, cement stone is a hydration product of the dispersive system "dispersed phase-dispersion medium" in which the dispersed phase is the binder's particles and the dispersion medium is water or aqueous solutions of chemical substances. The structure of the cement stone, according to [2], is determined by the shape and content of hydrated compounds. As well as by those grains that did not react, by the volume and size of pores, including technological cracks [1],

Section: Materials and Methods To Study Samples Of Non-autoclaved Aermentioning

confidence: 99%

The aerated concrete based on an integrated foam concentrate containing iron compounds

Shishkina

Nastich

Romanenko

et al. 2019

Self Cite

“…As shown in [13], the use of surfactants in ultra-small doses to change the structure of water can be an option to overcome these shortcomings. This is the approach used in work [14], which shows an increase in the strength of concrete when the structure of water is changed due to hydrophobic hydration, and in work [15] due to hydrophilic hydration. But even in these works, the homogeneity of concrete strength is not fixed either.…”

Section: Literature Review and Problem Statementmentioning

confidence: 99%

Ensuring uniformity of strength of fine-grained concrete based on modified composite cement

Shіshkina,

Domnichev

2024

Insufficient determination of the effect of surface-active substances introduced in extremely low concentrations on the formation of the stability of the properties of fine-grained concrete based on composite Portland cements determined the feasibility of conducting research in this area. The studies investigated the influence of the modification of composite cement with water activated by the use of the hydrophilic hydration mechanism. It has been proven that these factors include the type and amount of applied water nano modifiers. The analysis of the study results confirmed that the introduction of water activated by the mechanism of hydrophilic hydration into concrete in extremely small doses significantly increases the rate of formation of concrete strength and reduces the coefficient of its variation. Owing to this, the strength of the resulting modified fine-grained concrete based on composite cement at the age of 3 days exceeds the strength of the similar concrete without additives by 300 %, and at the age of 27 days – by 25 %. At the same time, the coefficient of variation of strength has a minimum value at the optimal amount of nano additive – water modifier. This allows us to assert the effectiveness of the revealed mechanism of modification of composite cement. Thus, there are reasons to assert the possibility of targeted regulation of the processes of formation of a strong homogeneous structure of fine-grained concrete based on composite cement by using water activated by the mechanism of hydrophilic hydration

“…As shown in [13], the use of surfactants in ultra-small doses to change the structure of water can be an option to overcome these shortcomings. This is the approach used in work [14], where it is shown that the strength of concrete increases when the structure of water is changed due to hydrophobic hydration, and in [15], it is due to hydrophilic hydration.…”

Section: Literature Review and Problem Statementmentioning

confidence: 99%

Formation of the strength of fine-grained concrete based on modified slag Portland cement

Shіshkina,

Piskun

2023

The object of research is fine-grained concrete on slag portland cement. Owing to the significant content of metallurgical industry waste in its composition, slag portland cement belongs to ecologically acceptable products. However, the insufficient rate of formation of its structure and, as a result, the main quality indicator, which is compressive strength, limits the field of use of slag portland cement. Therefore, in the studies, the goal was to increase the speed of formation of the strength of fine-grained concrete made on slag portland cement. The studies of the influence of modification of slag portland cement with water, activated by the use of the hydrophobic hydration mechanism, established the factors affecting the speed of formation and the value of compressive strength of fine-grained concrete made on slag portland cement. It has been proven that these factors include the type and amount of applied water nanomodifiers, as well as the type and amount of fine concrete aggregate. The analysis of the study results confirmed that the introduction of water activated by the mechanism of hydrophobic hydration into concrete in ultra-small doses significantly increases the rate of formation of concrete strength. Given this, the strength of the resulting modified fine-grained concrete based on slag portland cement at the age of 2 days exceeds the strength of the similar concrete without additives by 60 %, and at the age of 210 days – by 25 %. This allows us to assert the effectiveness of the identified mechanism of modification of slag portland cement. Thus, there are reasons to assert the possibility of targeted regulation of the processes of forming a strong structure of fine-grained concrete based on slag portland cement by using water activated by the mechanism of hydrophobic hydration