砂浆中邻近集料表面最近间距分布的数值模拟

采用具有粒子动态混合密实功能的SPACE 系统, 实现了高集料体积分数模型砂浆结构的生成。从而, 以3 种细集料粒径分布的模型砂浆(其中一种的粒径范围为0.125～1.34 mm , 另外两种的粒径范围为0.25～5.00 mm) 结构为例, 研究了集料细度和集料体积分数(φ= 40 %～70 %) 对邻近集料表面最近间距分布的影响。结果表明, 集料细度增加和集料体积分数增大都会使大尺度邻近集料表面最近间距出现的概率减小、小尺度邻近集料表面最近间距出现的概率增加, 且峰值概率的位置向小间距方向偏移。另外, 邻近集料表面最近间距的分区段累计概率结果分析表明, 3 种模型砂浆结构的邻近集料表面最近间距分布的57 %以上小于10μm。最后, 邻近集料表面最近间距的平均值的分析结果显示, 当集料体积分数在40 %～70 %之间变化时, 邻近集料表面最近间距的平均值在54.6～1.1μm 之间变化; 当砂浆中集料的体积分数在50 %～70 %之间变化时, 邻近集料表面最近间距的平均值与集料的体积分数基本上呈线性关系; 单位砂浆体积下集料的表面积的变化对邻近集料表面最近间距的平均值有影响, 但二者之间的比值并非常数。

NUMERICAL SIMULATION ON THE NEAREST SURFACE SPACINGDISTRIBUTION BETWEEN NEIGHBORING AGGREGATE GRAINS IN MORTAR

The SPACE system integrated with the dynamic mixing algorithm provided an opportunity to generate amodel concrete with high volume f raction of aggregate. In this cont ribution , influences of fineness and volume f raction (φ= 40 %～70 %) of aggregates were studied on the nearest surface spacing dist ribution between neighboringaggregate grains in model mortar for three types of aggregate size dist ributions (one with the size range of 0.125～1.34 mm , the other two with 0.25～5.00 mm) . The modeling result s demonst rate that increase in volume f ractionof aggregate or in fineness of aggregate has the same effect , i1 e. , the curve of the nearest surface spacing dist ribution moves toward the smaller surface spacing ; the value of maximum possible nearest surface spacing where peakprobability occurs also decreases. Furthermore , the result of interval cumulative probability of the nearest surfacespacing shows that more than 57 % of the nearest surface spacing probability is smaller than 10μm. Finally , the analysis of the mean value of the nearest surface spacing reveals that the mean value of the nearest surface spacing isbetween 54.6～1.1μm if the volume f raction of aggregate varied f rom 40 % to 70 %. And when the volume fractionof aggregate is kept in the range of 50 %～70 % , the linear relationship may be built between the mean value of thenearest surface spacing and the volume f raction of aggregate. The surface area of aggregate per unit volume of mortar does have influence on the mean value of the nearest surface spacing , but the ratio between them is not constant .