Development of Natural Perlite Based Concrete for Sustainable Construction

This study aimed to partially replace Portland Cement (PC) with environmentally friendly binders capable of improving the longevity of concrete. The new binders consisted of different proportions of natural pozzolan (perlite) with various fineness and particle size distributions. A step-by-step research program was designed to: (1) discover the optimum fineness of perlite powder and its optimum replacement level with cement; (2) investigate the rheological properties of the perlite-containing mixtures, and examine whether this binder can be used in selfconsolidating concrete; and (3) assess the weaknesses of the new binder, and improve its deficiencies by using nanomaterials such as nano-silica. The major variables included in this study were perlite replacement level, fineness of perlite, cement content, and water-to-binder ratio. The experimental program assessed the performance of the perlite-containing concrete mixtures, including fresh properties (flow-ability and workability), mechanical properties (compressive strengths), and transport properties (absorption, rapid chloride penetration, and rapid chloride migration). This study also compared the performance of perlite-containing concretes with that of an equivalent reference PC concrete, with similar flow and strength characteristics. The results of this study revealed that it was possible to find optimum binder proportions to achieve adequate plastic and hardened properties. For nearly all of the studied perlite-containing concretes, workability and flow-ability were in the acceptable ranges. The mechanical properties (compressive strength) of the perlite-containing concretes were slightly higher than those of the reference PC concrete, and the transport properties of the perlite-containing concrete were significantly better than those of the reference PC