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There is a great demand for low-rise construction in Uzbekistan. In this regard, it is necessary to continue research on the intensification of the technology of monolithic low-rise housing construction using primarily local waste from various industries. One of them is fly ash waste from the electric power industry. It is proposed to use fly ash as a filler in a cement-ash composition, and it is considered more affordable. The use of other industrial waste as fillers requires additional special processing such as drying and grinding. It was established that fly ash is more accessible for practical use. From the point of view of the structural theory of composite building materials, fly ash has a plasticizing ability, which in turn helps to reduce water consumption. It was established that it is appropriate to use mineral additives in combination with other additives in the preparation of concrete mixes with high workability and low cement consumption. To determine the strength properties, samples were prepared from an ash-cement mix with a water-cement ratio of 0.32, with a fly ash content of 85% of the total mass of the mix. The hardener additive (soda powder) was used at 1.5% by weight of the binder and activated in the mixers for 2 -4 minutes. The results of the study show that the additive accelerates the hardening process of the ash-cement mix by 80-90% at one day of age, due to activation, the strength increases by 11-22% for the mix with/without the additive, respectively. When the mix is activated, the particles are struck and the inert film is torn off from their surface and free access of water to the ash particles is ensured; this, in turn, leads to an increase in the number of hydrate formations and a deeper occurrence of hydration processes. We studied the effect of the sequence of loading components in a working mixer on strength indices. The strength of the mechanically activated mix with 80% fly ash content and 1.5% addition of soda powder, reached 18.5-19.5 MPa. An ash-cement mix for concreting monolithic low-rise buildings was developed.

Industrial enterprises are being built on a large scale in the desert regions of Uzbekistan. Concrete remains the main material in construction to this day. However, there is an acute shortage of sand of normal size. In this regard, an urgent task is to find effective and affordable technological methods for improving the properties of cement paste, concrete mix, and concrete on dune sand and cement savings. Taking into account our previous studies, the main attention was paid to establishing quantitative dependencies, changing the properties of cement paste and concrete from the introduction of sand dune fillers modified with additives of acidic (SDFMAA) and basic (marl) nature into their composition and the influence of methods for preparing a mixture of conventional and separate.

In the conditions of hot and dry climate, the concrete mixture quickly loses its mobility and workability. In this regard, it is necessary to plasticize it by introducing various surfactants; at the same time, the surfactant additive should not slow down the process of hydration and hardening. To ensure salt resistance, it is necessary to increase the density and strength of concrete. The proposed complex additive is obtained by joint grinding in a ball mill of soda sulfate melt and gossypol resin to a specific surface of 2800 cm2/g at the rate of 0.5-1.5% and 0.1-0.3% by weight of cement. From the obtained results, it can be seen that with an increase in the content of gossypol resin from 0.1 to 0.3%, the normal density decreases by 1.4-4 points, and the setting time due to the accelerating action of the soda sulfate melt is reduced at the beginning by 20-50 minutes and the end by 60 - 240 min. Reference cement for 28 days gained a strength of 56 MPa, with a complex additive of 60-68 MPa. The coefficient of salt resistance of the reference 0.55-0.65 and with a complex additive of 0.80-0.86 is observed due to the strength and density of the samples. Increasing the strength makes it possible to save 17-21% of cement.

In DHC and saline soils and groundwater conditions, the cement mix quickly loses its mobility and workability. In this regard, it is necessary to plasticize it by introducing various surfactants. However, the surfactant additive used should not slow down the process of hydration and hardening. To ensure salt resistance, it is necessary to increase the density and the strength of concrete. The proposed complex additive was obtained by joint grinding in a ball mill of a soda-sulfate alloy (SSA) and gossypol resin (GR) to a specific surface area of 2800 cm2/g at the rate of 05, -1.5%, and 0.1-0.3%, respectively, of the cement mass. The complex additive was introduced into the mixing water of the cement mix. From the research results obtained, it is seen that with an increase in the content of GR from 0.1 to 0.3%, the normal density decreases by 1.4-4 points, and the setting time (due to the accelerating action of the SSA) decreases at the beginning by 20-50 minutes, and at the end by 60-240 minutes. In 28 days, the control cement gained the strength of 56 MPa, and with a complex addition - 60-68 MPa. The introduction of a complex additive led to an increase in the salt resistance coefficient in the reference cement up to 0.55-0.65, and in the cement with a complex additive up to 0.80-0.86; an increase was observed due to the strength and density of the samples. By increasing the strength, it is possible to save 17-21% of cement.