EVOLUTION OF HYDRATION OF CEMENTS WITH COAL BOTTOM AND FLY ASH BY NON – DESTRUCTIVE TECHNIQUES AND POROSIMETRY

Author(s): Menéndez, E., Alvaro, A. M. and Andrade, C.
Paper category: Conference
Book title: XIII International Conference on Durability of Building Materials and Components - XIII DBMC
Editor(s): Marco Quattrone, Vanderley M. John
Print ISBN: none
e-ISBN: 978-2-35158-149-0
Publication year: 2015
Pages: 1073-1080
Total Pages: 8
Language: English

Abstract: Concrete and steel are currently the most widely used construction materials. The main component of concrete is cement, mainly constituted by clinker. The manufacture of clinker consumes non-renewable resources, both energy and raw materials, and releases CO2. The partial replacement of clinker by supplementary materials minimizes these disadvantages and usually provides suitable mechanical and durable properties of cement based materials. Therefore, the use of supplementary materials as addition to cement is common and utterly accepted by worldwide standards.

Coal fly ash is one of these allowed additions to cement. Fly ash is, like coal bottom ash, a residue from coal-pulverized power plants. While fly ash is usually reused as a highvalue by-product in cement manufacture, bottom ash is merely reused as a low-cost filling civil construction, at best scenario. However, some studies have recently reported good pozzolanic and mechanical properties of cements with coal bottom ash as addition.

In this paper, the evolution of the hydration process of cement based materials manufacture with coal bottom ash and fly ash was studied. Several parameters were monitored to this purpose: weight change, electrical resistivity, ultrasonic pulse and porosity. All of them were used to characterize the evolution of the pore structure in cement based materials, an important characteristic that has a fundamental influence on its durable properties. The results showed interesting similarities between cements based materials with bottom ash and fly ash at a same percentage replacement.

Online publication: 2015
Publication Type: full_text
Public price (Euros): 0.00