CONCRETE

[:ru]Федоров П. А.[:en]Fedorov P. A.[:] [:ru]УГНТУ, Россия[:en]USOTU, Russia[:]

[:ru]Анваров Б. Р.[:en]Anvarov, B. R.[:] [:ru]аспирант, Уфимский государственный нефтяной технический университет, г. Уфа, Россия[:en]postgraduate student, Ufa State Petroleum Technological University, Ufa, Russia[:]

[:ru]Латыпова Т. В.[:en]Latypova, T. V.[:] [:ru]канд. техн. наук, доц., Уфимский государственный нефтяной технический университет, г. Уфа, Россия[:en]Cand. Eng. Sc., Associate Prof., Ufa State Petroleum Technological University, Ufa, Russia[:]

[:ru]Анваров Р. А.[:en]Anvarov, R. A.[:] [:ru]канд. техн. наук, доц., Уфимский государственный нефтяной технический университет, г. Уфа, Россия[:en]Cand. Eng. Sc., Associate Prof., Ufa State Petroleum Technological University, Ufa, Russia[:]

[:ru]Латыпов В. М.[:en]Latypov, V. M.[:] [:ru]д-р техн. наук, проф., Уфимский государственный нефтяной технический университет, г. Уфа, Россия[:en]Dr. Eng. Sc., Prof., Ufa State Petroleum Technological University, Ufa, Russia[:]

Alitinform №4-5 (16) 2010 г. 54-60 p.

Abstract

Concrete carbonation is the most frequent cause for a sharp decrease in exploitation reliability of reinforced concrete structures with a service life of over 20…30 years, due to cracking (or even peeling) of the protection layer of concrete because of corrosion of reinforcement elements. In some cases, corrosion damage of reinforced concrete structures is observed during the first years of exploitation. This happens due to three main reasons: low quality of concrete (its high porosity level); small thickness of protection layer; high concentration of carbon dioxide (in basements, reservoirs, technological plants with СО₂ emission).

In order to calculate durability of a structure under conditions of carbon dioxide presence in the air, a calculation model (i.e. a formula) is needed. However, there is no such formula in the existing standard SNiP 2.03.11-85 “Protection of building structures against corrosion” or in other documents regulating protection of reinforced concrete. A normative service life period for structures is also lacking. The new state standard GOST 31384-2008 “Protection of concrete and reinforced concrete structures against corrosion” gives two interrelated parameters: guideline service life period of the structures (50 years) and admissible depth of defects, in environments of a different degree of aggression. However, there is no formula to calculate concrete carbonation depth in this regulative document either. The reason for this is first of all that there is still no common opinion about such a formula. Another reason is the complexity of reliable forecasting the two core parameters of the exploitation environment, such as concentration of carbon dioxide, and temperature-humidity conditions.