引气混凝土气泡尺寸分布的三维重构

基于体视学和几何概率理论给出了引气混凝土三维气泡尺寸重构方法,由二维平面上气泡截面圆的直径分布计算气孔的实际尺寸分布,并生成了一个多尺度分布的立方体模型结构验证了该三维重构方法的合理性.然后,使用邻近粒子表面最近间距的解析解研究了气泡细度和混凝土含气量对邻近气泡表面最近间距平均值的影响,并与用传统方法得到的气泡间距因子进行了比较.结果表明,在含气量相同的条件下,用传统方法得到的气泡间距因子是邻近气泡表面最近间距平均值的3-4倍.该方法的给出,为从二维截面上获得的引气混凝土中的气泡截面圆信息获取实际气泡在三维空间中的气泡间距信息提供了依据.

3-dimensional reconstruction of size distribution of air voids in air-entrained concrete

By virtue of stereological approach and geometrical probability theory, this paper presents 3-dimensional reconstruction methodology of size distribution of air voids based on the information of 2-dimensional size distribution of intersecting circle on section plane of concrete. The validity of the 3-dimensional reconstruction technology was verified by a multi-size sphere packing model structure with periodic boundaries. Then, the previous proposed analytical solution of the nearest surface spacing between particles was employed to investigate the influence of air void fineness as well as air content on the distribution of the nearest surface spacing between neighboring voids. The mean value of the nearest surface spacing obtained based on the above mentioned analytical solution was compared with spacing factor based on the traditional approach. The result demonstrates that the value of spacing factor derived from traditional approach is 3-4 times the mean value of the nearest surface spacing at the same air void content. Development of such framework provides a clue to quantify the spatial distribution of air voids based on the information obtained from section plane of concrete.