Abstract
Production of precast concrete requires a large amount of thermal energy, especially the technological process to accelerate concrete hardening. Application of helioforms with various translucent and solar perceptive coatings can be considered as one of the directions of solar energy application for thermal treatment of precast concrete. Heliothermаl treatment of precast concrete products in helioforms, using such coatings ,has been developed in the late 70th of the last century on the basis of research, conducted by scientists of scientific-research institutes of the Commonwealth of Independent States. Various ways of heliothermаl treatment of concrete using translucent and solar perceptive coatings were proposed and tested. One of the simplest and most effective ways to accelerate hardening of concrete using solar energy, which found quite wide application in practice, is thermal treatment of heavy concrete products in helioforms with translucent and heat insulating coatings (THIC). This method of heliothermаl treatment in regions with hot climate allowed to abandon for 5-6 months a year (for a number of slab by products) the heat-humidity treatment with the use of other heat carriers; to reduce demand for water used to generate saturated water steam; to create seasonal testing grounds for thermal treatment of concrete with solar energy application; to create a clean quality environment for the production; and with all this, to ensure the diurnal cycle of manufacture of products. However, for heliothermаl treatment with the use of THIC coatings helio top covers are needed, that require constant care of translucent liners; impossibility to use the existing helio top covers for the manufacture of products of another type/size; difficulty in manufacture of products of complex shapes according to this technology, etc. Development of advanced technologies of solar energy application to accelerate the hardening of concrete in the manufacture of concrete products will ensure high quality of precast concrete products due to creation of optimal structure of concrete as a result of the most favorable temperature - humidity conditions of concrete hardening, rational formation of temperature fields in products and heat -and -mass transfer. New approaches to the technology of heliothermal treatment of precast concrete structures in dry hot climate of the Republic of Kazakhstan save 50-100% of traditional fuel at their thermal treatment of precast concrete; ecologically clean quality environment, free of smoke emissions from boiler installations; guaranteed high quality of products and constructions at the diurnal cycle of turnover of the forms, reduction of the cost and energy intensity of construction.
