The influence of fly ash as substitute of cement in the durability of concrete

Abstract

Limitation of transport capacity through the concrete is one of the key points in the improvement of the material’s durability. The use of fly ash as an admixture to concrete is widely extended; a general consensus has been established due to the pore size reduction produced by the ashes. Nevertheless, the importance of the micro-structural and composition changes in mechanical and durable properties is not well defined. In the present study the use of fly ash has been considered as substitute of cement in the design limits. The concrete mechanical properties and its porous structure were evaluated. The tests included porosimetry and water permeability tests. In order to characterize the hydration products and its evolution with time TG and DTA analysis were performed. This work studies the fly ash concrete hydration process, their influence in the porous distribution, and the mechanical and durable properties of the material.