APPLICATION OF MATURITY CONCEPT IN CONCRETE WITH RHA ADDITION

摘要

Steam curing is used to accelerate cement hydration reactions with the purpose to enhance mechanical strength of concrete at early ages, since hydration reactions are temperature dependent. In order to evaluate the influence of temperature on the development of mechanical properties of concrete, the maturity concept is used. This method estimates the development of these properties according to the temperature history of concrete along the curing process. The temperature influence can be indicated by the Apparent Activation Energy (Ea) value. The higher is the Ea value, the more energy will be necessary to start the reactions, and thus the velocity of these reactions will be affected by temperature. This work is based on an experimental study of steam-cured concrete made with 5% and 10% of nee husk ash (RHA) addition in which the development of some mechanical properties was investigated. The rice husk ash used was obtained from uncontrolled autocombustion of rice husk, in an open chamber, without any control of temperature and burning time. The mechanical properties investigated were the compressive strength, the tensile strength, and the modulus of elasticity. The results indicate the influence of RHA addition and its dosage on the hydration reactions of cement and the mechanical properties of steam-cured concrete.