Mathematically Relationship between Compressive Strength and Non-Destructive Tests for Colored Concrete Made by Bentonite

Abstract

This study evaluated the viability of generating colored geopolymer concrete utilizing bentonite as the binder and analyzed the impact of pigment on the diverse properties of geopolymer concrete. The geopolymer concrete enhanced with two types of pigment, specifically iron oxide hydroxide in "red" and "yellow" hues, after which tests for compressive strength, rebound number, density, and ultrasonic pulse velocity were conducted and established the mathematically relationship to find compressive strength depend on non-destructive tests. The maximum compressive strength was attained by adding 1% colors, resulting in a 2.7% increase for red geopolymer concrete and a 1.8% increase for yellow geopolymer concrete compared to the reference mixture value. The optimal rebound values can achieved by incorporating 1% yellow and 3% red, resulting in an 8% increase in red and a 15% increase in yellow from the reference value. The density escalates with the increasing proportion of the supplementary pigment. The highest density values attained by adding 1% of red and yellow pigment, resulting in respective increases of 1% and 3% for red and yellow. The maximum ultrasonic pulse velocity values rose by 1.7% with the addition of 1% yellow pigment and by 2% with 1% red pigment. The ideal amount is 1.2%, as it improves characteristics and decreases costs when employing smaller pigments.