Thermal and microstructure properties of cement mortar containing ceramic waste powder as alternative cementitious materials

In the present study, thermal and mechanical characteristics of cement mortar incorporating Ceramic Waste Powder (CWP) as cement replacement were examined. The cement of the mortar mixes has been replaced with CWP which was provided from Almas-Kavir Company (Iran) in amounts of 5%, 10%, 15%, 20% and 25% (by weight of cement). The mortar specimens were cured in water for 28 days, and then the hardened specimens were exposed to temperatures of 200 degrees C, 400 degrees C, 600 degrees C, and 800 degrees C. This paper represents the thermal performance of CWP as cement replacement based mortar, including the mechanical strengths, mass loss, dry bulk density, ultrasonic pulse velocity and total porosity of the cement mortars. The X-Ray Diffraction (XRD) and Scanning Electron Micrograph (SEM) analyses of mentioned mortars have been also measured to explore the microstructure of heat treated specimens. Additionally, surface cracks of the mortar specimens were examined. Experimental results explain that specimens containing CWP exhibit higher compressive and flexural strengths than control specimens at elevated temperature. The study has also shown that mortar specimens containing CWP improved the thermal resistance of mixes. The XRD analyses showed that the mixes containing CWP have a lower intensity of portlandite peaks than the control mix, and SEM images explained that using CWP reduced the porosity. It should be mentioned that incorporating CWP as cement replacement improved several characteristics at elevated temperatures. (C) 2019 Elsevier Ltd. All rights reserved.