Alkali-Activated Lightweight Aggregate Concrete

Nowadays, there is a wide-spread concern, especially in the scientific community, to assure the sustainability of the built environment. The development of eco-efficient materials, particularly of alkali-activated (AA) cements as an alternative to ordinary Portland cement (OPC), is a very interesting solution in this scope. Herein, it is described a study conducted aiming to combine the advantages of AA binders with those of lightweight aggregate concrete (LWAC), obtained from ground granulated blast furnace slag (GGBFS), as by-product, mixed with different types and dosages of alkali activators. Tests were performed on concrete and mortar specimens to characterize the following properties: (i) density, (ii) compressive strength, (iii) tensile strength, (iv) Young’s modulus, and (v) shrinkage. Moreover, the evolution of the compressive strength and of the Young’s modulus of these alkali-activated lightweight aggregate concrete (AALWAC) was compared to standard hardening curves defined for OPC-based concretes.