Relationship Between Compressive Strength and Non-destructive Tests of Colored Geopolymer Concrete Based on Fly Ash

In this work, some physical and mechanical properties of colored geopolymer concrete based on fly ash were studied. Geopolymer concrete was colored using two types of dyes (chromium oxide which gives green color and iron oxide hydroxide which gives yellow color). The geopolymer concrete samples were subjected to controlled curing conditions at 30°C. At the age of 28 days, all samples were tested under compressive loading and non-destructive tests (NDTs) were also performed such as ultrasonic pulse velocity, Schmidt hammer, dynamic elastic modulus, and dynamic shear modulus. The test results were used to obtain a mathematical relationship between the compressive strength on the one side and the NDTs tests on the other side. This relaionship can be used to estimate the compressive strength of the colored geopolymer concrete by the means of NDTs. In addition, the results proved that the percentage of adding 2% of the dye (for the green color) and 1% of the dye (for the yellow color) is the optimum percentage of the addition.