No abstract

Nowadays, reducing the amount of dust in urban atmosphere is an urgent task for the majority of industrially advanced countries in the world. Road construction works are one of the factors influencing the increase in the dust particles concentration in the atmospheric air. The authors present the treatment schemes for dust emissions from mobile and portable asphalt concrete plants applying dust collectors with countercurrent swirling flows. They conducted an analytical investigation of the operation of the designed layout schemes applying dust collectors with countercurrent swirling flows (CSF), dust concentrators and bag filters. The justification of the optimum layout scheme was presented.

The concept of safety and assurance of vital human activities in urbanization is one of the most significant backbone concepts of human ecology. The comfort of residential buildings is largely owed to the radiation properties of the construction materials used. Therefore, the radiation-related hygienic support of technological processes and construction procedures is an important issue for the construction industry. Solving problems associated with improving the radiation safety of urbanized complexes depends on implementing legislation in the sphere of limiting human exposure to the impact of naturally occurring radionuclides. The paper presents the results of studies carried out by the authors on the specific activities of naturally occurring radionuclides in the construction materials manufactured and used in the Volgograd region. Through these large-scale studies, it was found out that the construction materials manufactured in the Volgograd region are in compliance with the national legislative and standard requirements; they are referred to as class 1 and can be applied for the construction of residential and public buildings.

At construction industry enterprises, in particular at plants manufacturing coloured calcium silicate bricks, aerosols and fine dusts of raw materials are formed in the course of various processes of grinding, transporting, mixing, pouring etc. They are characterized by a high degree of dispersion and high concentration in working zone air and exceed the Maximum Permissible Concentrations by several times. One of the most significant reasons for increased dust amount in the air of working zones of industrial shops is the presence of locations of dust wastes storage. For the purpose of complete evaluation of dust conditions inside an industrial shop for components mixing for coloured calcium silicate bricks, it is necessary to investigate the dispersion process and the aerodynamic properties of the finest dust – colour pigment. The authors have conducted experimental investigations of the aerodynamic properties of colour pigment for calcium silicate bricks and formulated the conclusions.

The key factors for obtaining coloured calcium silicate bricks is the high degree of dispersion and precise dosage of the colouring matter, as well as its uniform distribution in the silicate mixture. Dust particles of a colour pigment pose the most harmful effect on the health of workers at the industrial shop. In the course of components mixing, a large amount of dust from sand, lime and pigment is released into the working zone air since the process of components mixing implies materials pouring while proportioning as well as vigorous mechanical mixing. For the purpose of the quantitative and qualitative analysis of the working zone air contamination in a components mixing shops, it is necessary to investigate the dust conditions at the shop, the particle size distribution of the mixture components, the concentration of hazardous substances in the working zone air, the aerodynamic properties of dust.