jismart2019043: Consideration on Appearance Limitations of Fly Ash Blended within Concrete

Abstract

In this paper, we measured the color of concrete mixed with fly ash, and examined an appearance limit of the color through psychology experiment and logistic-regression analysis. As a result, the following was clarified. It was admitted that fly ash had the effect to change color of the concrete according to its own color, and the effect to decrease lightness and metric chroma (CIELAB color space) of the concrete. It was estimated that the testee preferred the concrete recycled by-product provided that the lightness was more than -8.0 of ordinary concrete and the metric chroma was less than 6.5 of ordinary concrete. In such case, the lightness of fly ash must be more than -0.26 of OPC and the metric chroma of fly ash must be less than 0.38 of OPC, when a quarter of OPC is replaced with fly ash.