Research on decalcification degradation process of cement stone

Abstract

An accelerated laboratory method (saturated ammonium nitrate solution immersion method) was used to analyze the degradation of cement decalcification process. By studying the changes of intensity, volume, elastic modulus, quality, pH value, the Ca/Si, and mineral phase, it could be found that the first cement decalcification degradation process was the decalcification of calcium hydroxide, and then CSH gel, AFm, etc. The secondary ettringite deposition happened and the decalcification degradation depth was proportional to the square root of time. Moreover, the corresponding strength of cement would be gradually reduced, cement rock volume shrinkage occurred, pH values decreased, the surface elastic modulus decreased down to a certain level, and slightly changed and the Ca/Si was 3.1 from the beginning and lasted down to 1.3.

Keywords

accelerated test / decalcification / Ca/Si ratio / degradation process

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