Development and Optimization of Cements with Reduced Environmental Impact - Assessing Cement Durability and Concrete Engineering Properties

Rodrigo Reichenbach de Sousa Condeço

Key information

Authors:

Rodrigo Reichenbach de Sousa Condeço (Rodrigo Reichenbach de Sousa Condeço)

Supervisors:

Rodrigo Manuel Lino dos Santos (Rodrigo Manuel Lino dos Santos); Rogério Anacleto Cordeiro Colaço (Rogério Anacleto Cordeiro Colaço)

Published in

February 11, 2025

Abstract

Cement is a fundamental material in the construction industry, with 4.1 billion tonnes produced annually. However, cement production is an energy-intensive process with significant CO2 emissions, which adversely impact the environment. This has underscored the urgent need for alternatives to reduce emissions. Several solutions are already being implemented in the industry, such as efficient kilns, utilizing waste as fuel, and incorporating Supplementary Cementitious Materials to reduce overall clinker consumption. Recently, Alkali Activated Materials (AAM) have emerged as a promising solution, attracting interest for their potential to mitigate environmental impacts while maintaining performance. X-Clinker, a proposed AAM, serves as the focal point of this study. This involved extensive testing and comparison with Ordinary Portland Cement across multiple properties, including hardened and time-dependent characteristics, durability testing, and reinforced concrete properties. This analysis aims to deepen the understanding of X-Clinker’s behavior under conditions typical for cement and concrete testing, providing valuable insights into its potential applications and advantages. The results indicate that the X-Clinker demonstrates superior performance in several key areas, including compressive strength, resistance to various acidic and basic environments, resistance to chloride ion penetration, and resistivity. Additionally, it exhibits comparable performance in flexural strength and splitting tensile strength; however, further work is required to understand the bond stress between concrete and steel reinforcing bar. Finally, it falls short in modulus of elasticity, creep, shrinkage, and certain matrix-relevant tests, such as air permeability, capillary absorption, and carbonation resistance.