Деструктивные явления при некачественном прогреве монолитных железобетонных конструкций

Abstract

The growth of the number of the building floors inevitably leads to an increase in the construction period and, consequently, to the need for monolithic reinforced concrete structures in winter. Electric heating by means of heating cables is the most widespread method of concrete curing in winter conditions in the Central region of Russia. The risk of defects in monolithic reinforced concrete structures increases under certain conditions. This risk is related to various types of technological process faults. The main types of monolithic structures defects have been repeatedly described. But there are practically no papers describing the types and causes of defects associated with failures during electric heating of concrete. The author has developed a block diagram of the main defects, and the main reasons for their occurrence have been identified. The paper summarizes the experience gained during two winter periods at the construction sites of Moscow city belonging to unique buildings and structures. Operational and quality inspection of the construction was performed. The author identified groups of defect causes: cable installation and installation errors; heating regime errors. The author identified specific types of defects for each group, and also gave recommendations on their avoidance in the future. The paper provides a ‘check list’ of parameters that must be checked during electric heating with heating cables. The checklist shows the control points that minimize the risk of defects.