Durability of Two Eco-Sustainable Commercial Cements

Abstract

The manufacture of Portland cement clinker produces high CO2 emissions into the atmosphere. Portland cement concrete is the most widely used construction material globally, so its emissions are an environmental problem. For years, cements with partial substitution of clinker by by-products of the industry, such as fly ash (FA) and blast furnace slag (BFS), more recently called "ecological cements", have been researched. However, its use shows some limitations due to ignorance of its durable behaviour. In Spain, the partial substitution of clinker by FA or BFS in cement has been on the market for some time, although there are still doubts regarding its behaviour against carbonation. This research studies the mechanical and durable characteristics of two eco-friendly commercial cements composed of clinker, FA and BFS, and compares them with clinker cement. In general, the correct behaviour of cement with additions can be indicated in relation to their mechanical properties and against the penetration of chlorides. Concerning the results of accelerated carbonation, the cement with BFS showed values similar to those of the reference cement, while the FA cement behaved in a way that could be qualified as not appropriate for its possible structural use.