粉煤灰混凝土二维、三维碳化及其叠加系数的研究

通过研究不同粉煤灰掺量(0%、15%、20%、40%、60%)下高性能混凝土的二维和三维碳化深度,建立二维和三维碳化的测试方法,提出二维和三维碳化的数学模型,定义二维和三维碳化的叠加效应系数,并给出二维和三维叠加效应系数的数学公式。试验表明,混凝土的二维、三维碳化与一维碳化相似,也是服从时间的指数函数,同时具有明显的叠加效应;早期碳化时,二维叠加系数能到4.0以上,三维叠加系数能到6.0以上;碳化至28d(相当于自然碳化50年)时,二维叠加系数能到2.0以上,三维叠加系数能到4.0以上;叠加系数服从经时衰减函数。

RESEARCH ON 2-DIMENSION,3-DIMENSION CARBONATIONS AND SUPERPOSITION COEFFICIENT OF FLYASH CONCRETE

Through a study on 2-D and 3-D carbonations of high_performance concrete with different flyash proportion(0%,15%,20%,40%,60%), the test methods of 2-D and 3-D carbonations are built; the mathematical models of 2-D and 3-D carbonations are also proposed. The superposition coefficient of 2-D and 3-D carbonations are defined; the mathematic formula of the superposition coefficient is given. The experiment indicates that the carbonations of 2-D and 3-D are similar to that of 1-D, which obey the exponential function of time t. At the same time,they have superposition coefficient obviously. During the early stage carbonation, the superposition coefficient of 2-D can be over 4.0, and it can be 6.0 of 3-D. During the carbonation of 28 days (which corresponds to natural carbonation of 50 years), the superpostion coefficient of 2-D can be over 2.0, and it can be 4.0 of 3-D. The superposition coefficient obeys the attenuation function through time t.