评测混凝土粗糙度的一种新方法及其分形表示

A New Method and Its Fractal Expression for Evaluating Roughness of Concrete

增加粗糙度是提高新老混凝土粘结性能的常用的方法。目前,国内外还没有相应的标准或规程对混凝土粗糙度的评测方法作出明确的规定,基于灌砂法的原理建立了一种新的混凝土表面粗糙度的评测方法-测试仪法。分别采用灌砂法、测试仪法对24个劈裂面进行测量分析,发现测试仪法是比灌砂法更先进更准确的测量粗糙度方法。利用分形理论,研究了分维值与粗糙度的关系,发现高差法分维值与粗糙度无正相关性,变步距法分维值与粗糙度有一定的正相关性。通过对两种分维值深入分析,综合利用高差法分维值和变步距法分维值,建立了测试仪法粗糙度与分维值的拟合公式。发现测试仪法粗糙度值随着测量步距的增大而减少,高差法分维值与其缩减系数有较好线性相关性,建立了拟合公式,达到了简化测量的目的。

Increasing roughness is a common method to improve the bond performance of new-old concrete.At present,none of relevant standards or regulations make a clear definition of concrete roughness evaluation methods,based on the principle of sand-pouring method,a new method-tester method for evaluating surface roughness of concrete is developed in this paper.The 24 splitting surfaces are measured by sand-pouring method and tester method,it is found that the tester method is more advanced and accurate than the sand-pouring method.Based on the fractal theory,the relationship between fractal dimension and roughness is studied.It is found that there is no positive correlation between height difference method fractal dimension and roughness,and there is a certain positive correlation between variable step method fractal dimension and roughness.By depth analyzing the two fractal dimension,the fitting formula of tester method roughness and fractal dimension is established by comprehensive using height difference method and variable step method.It is found that the tester method roughness value with the increase of measuring step,and there is a good linear correlation between height difference method fractal dimension and reduction coefficient,the fitting formula is established,and the purpose of simplifying the measurement is achieved.