An Investigation on Aggregate Distribution in Concrete

Abstract

Falling behavior is generally studied by mathematicians. The first study is conducted by Comte de Buffon with name “Falling needles experiment” and is widely known. Buffon researched the falling needle behavior finding the fall of needles in relation with Pi. However, although aggregates are fallen to the mould in cement paste, falling behaviour of concrete is rarely studied considering the statistical parameters of the fall.

Accordingly, an experimental study is conducted to research the falling behavior of the aggregate and its distribution in cementitious composite “concrete”. A typical concrete design according to TS 802 is considered, and many cylindrical concrete specimens are produced in the laboratory. Then, a method is improved to determine the aggregate location on a surface of sliced concrete face and coordinates of the maximum size aggregates are determined. 

As a result, the falling behavior of the aggregates in concrete is found in relation with Pi as similar as falling needles. Pi is calculated as “3.139534884…” with a very small error while Pi is “3.141592654…”. In addition, it is found that mould edges cause a wall effect decreasing aggregate concentration near the edges. When gone from the edge to “a region” of concrete (it is named as concrete core in this paper), the aggregate concentration increases.