Investigation of mechanical and durability properties of brick powder-added White Cement composites with three different fibers

Abstract

• 5% brick powder increased the strength results of White Cement composite production. • The highest results were obtained with the crimped steel fiber for fiber-reinforced mortar. • The lowest results were obtained with the copper-coated steel fiber for fiber-reinforced mortar. • The brick powder and fiber added composites resisted the durability tests. Traditional Portland Cement is used extensively in the construction industry today. Portland Cement has a gray color and has been explored with numerous substitutes. With the increasing interest in concrete technology, the interest in composite materials with higher performance and strength has gained more importance. White Cement (WC) is an important cement type in this field. However, studies of substitute materials for White Cement are limited and more research is needed. In this study, while White Cement and clay brick powder (CBP) were substituted at three different rates (5%, 10%, and 15%), three different fibers (copper-coated (CC) steel fiber, crimped (C) steel fiber, and basalt (B) fiber) were used at the ratio of 0.4% to examine the effect of fibers at the same time. The compressive and flexural strengths of the prepared series were investigated for 28 and 90 days. Three different durability tests were applied after 90 days: elevated-temperature test (250, 500, and 750 °C), freezing-thawing test (90 cycles), and sulfate effect (90 days). Following the durability tests, weight and strength values were compared. In addition, SEM and XRD analyzes were made while making comparisons before and after the durability test of the samples and a visual examination was made in the durability conditions. The use of 5% brick powder increased the strength values due to the formation of C-A-S-H and C-S-H gels due to its higher Al 2 O 3 and SiO 2 content, while the use of higher brick powder caused a decrease in strength. While the fibers contributed positively to the strength values, the highest increase was in the longer crimped steel fiber added sample and the lowest increase was in the shorter copper-coated steel fiber added sample. While there was a 13% increase in compressive strength in the crimped steel fiber and 5% brick dust added sample compared to the control sample, there was a 21% increase in flexural strength. As a result of the durability tests, the samples behaved in similar order and maintained their stability despite significant losses.