STUDY ON THE EFFECT OF NATURAL CLIMATE ON THE CORROSION OF REBAR IN CONCRETE

Natural climate is an important factor that affects the durability of reinforced concrete (RC) structures, and therefore must be taken into account in the degradation models for durability of RC structures. In order to investigate the development of corrosion rate of the reinforcing rebar in concrete under natural climate environment, the long-term test on the corrosion of the rebar in concrete was carried out under the sheltered condition in natural climate; at the same time, the test on the response of the micro-environment of concrete corresponding to the natural climate environment was also conducted in order to analyze the effect of natural climate on corrosion of rebar in concrete. The results show that, the corrosion rate of the rebar in concrete under natural climate environment is fluctuant and time-dependent; the changes in environmental condition of the micro-environment of concrete lag behind that of natural climate, especially in relative humidity. It is concluded that the corrosion of the rebar in concrete is directly affected by the micro-environment of concrete that depends on the random fluctuations of natural climate, and temperature is the primary factor that influences the corrosion of rebar in concrete under sheltered condition of normal atmospheric environment.