composite clinkerless mineral binders — Строительные материалы и изделия

Development of geopolymer binders

https://doi.org/10.58224/2618-7183-2024-7-6-4

Murtazaev S-A.Yu., Salamanova M.Sh., Saidumov M.S., Gatsaev Z.Sh., Alaskhanov A.Kh., Murtazaeva T.S-A.

Аннотация

The scale of consumption of raw materials is large, and to a greater extent, it is the building materials industry that has a detrimental effect on the environment, thereby disturbing the pristine appearance and landscape of nature. Production volumes of Portland cement clinker have exceeded the mark of 5 billion tons per year. But the key dilemma lies in the emission of greenhouse gases, because during the high-temperature processing of raw materials to produce clinker, carbon dioxide, methane and nitrous oxide are released into the atmosphere.
At the same time, slag-alkali and geopolymer binders can be considered as an alternative to resource-intensive Portland cement; they have found practical application in many developed countries of the world. A large backlog of research has allowed the authors of the work to model materials of both technogenic and natural origin “technogenic reaction powder – natural component – alkaline activator” in one binder system. Microanalysis confirmed the effectiveness of the integrated use of sodium silicofluoride and finely dispersed bentonite additives in the binder system, which had a beneficial effect on the pore structure of the stone and the properties of the cement stone.
Using a properly designed binder composition “aspiration dust – finely dispersed bentonite – sodium silicofluoride – alkaline binder”, it is possible to obtain high-quality and durable composites with a low carbon footprint, thereby solving many environmental problems.

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Hydraulic activity of crushing screenings of waste open-hearth slag

https://doi.org/10.58224//2618-7183-2024-7-3-3

Bratchun V.I., Bespalov V.L., Ahmed A. Alani, Zhevanov V.V., Romasyuk E.A.

Аннотация

Theoretically and experimentally studied the hydraulic activity of crushing screenings of waste open-hearth slag and methods for intensifying the hydration hardening of slag stone during operation. During the hardening of slag stone, three periods of pronounced syneresis with gel new formations strengthening the material were established at the ages of 28 – 60, 90 – 180 days and 1 – 2 years. The first period of syneresis, in contrast to the subsequent ones without changing the strength of the samples, is recorded by the linear shrinkage of the samples, the squeezing out of bound water and the increase in pH. The introduction of two percent of cement dust or lime into the crushing screenings of waste open-hearth slag leads to the strengthening of the slag stone at 28 and 90 days of age by 3 – 4 times. However, by the age of two years, the strength of the samples stabilizes. This fact indicates that the additions of cement dust or lime are not additional binders, but hardening accelerators.

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Study of the characteristics of pavement elements made of rein-forced soil with the use of secondary resources

https://doi.org/10.58224/2618-7183-2023-6-6-2

Sinitsin D.A., Elrefaei A.E.M.M., Glazachev A.O., Kuznetsov D.V., Parfenova A.A., Volokitina I.E., Kayumova E.I., Nedoseko I.V.

Аннотация

The importance of using secondary resources on the basis of industrial waste is understood by both governments of developed countries and business (production of Portland cement using ground metallurgical slag as a mineral additive at Novotroitsk, Magnitogorsk, Sterlitamak, Katav-Ivanovsk and other plants in the South Urals). The use of secondary raw materials requires the creation of technological infrastructure for processing of secondary raw materials, the costs of which can be quickly recouped due to the cheapness and availability of industrial secondary raw materials and freeing the territory from environmental pollution. In order to recoup the costs of the infrastructure, it is necessary to guarantee full compliance of the quality of pavement elements with the requirements of GOST R 59120-2021. Secondary raw materials have a great variety and laboratory analysis of the quality of pavement elements is required in order to design compositions with the best quality, satisfy-ing all regulatory requirements. In our work the authors present the results of laboratory research and evaluation of the possibility of using clinker-free lime-slag binder based on the mineral product of so-da production and metallurgical slags to strengthen and stabilize soils for their use in pavement struc-tures in the construction of roads for various purposes and climatic zones.
It is experimentally shown that the addition of lime-slag binder in the amount of 8-10% of the dry weight of both cohesive (loamy soil, loamy sand) and non-cohesive (fine sand) soil allows to obtain reinforced soil with improved strength and elastic-deformative characteristics, which can be used in-stead of scarce natural crushed stone and gravel in the construction of underlying layers of pavements in the construction and reconstruction of highways. This technology can be used not only in the Rus-sian Federation, but also in a number of other countries, including those with hot dry climates (e.g., the Republic of Egypt).

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