Mix Design and Mechanical Properties of Fly Ash and GGBFS-Synthesized Alkali-Activated Concrete (AAC)

• Main Authors: Ramamohana Reddy Bellum, Ruben Nerella, Sri Rama Chand Madduru, Chandra Sekhar Reddy Indukuri
• Format: Article
• Language: English
• Published: MDPI AG 2019-05-01
• Series: Infrastructures
• Subjects: SEM; XRD; geopolymer binder; CO₂; fly ash; GGBFS; properties
• Online Access: https://www.mdpi.com/2412-3811/4/2/20

Cement is one of the construction materials widely used around the world in order to develop infrastructure and it is also one of the factors affecting economies. The production of cement consumes a lot of raw materials like limestone, which releases CO₂ into the atmosphere and thus leads to global warming. Many investigations are underway in this area, essentially focusing on the eco-accommodating environment. In the research, an alternative material to cement binder is geopolymer binder, with the same efficiency. This paper presents scanning electron microscope (SEM) and X-ray diffraction (XRD) analysis of factory byproducts (i.e., fly ash and ground granulated blast furnace slag (GGBFS)). The mix design process for the manufacture of alkali-activated geopolymer binders synthesized by fly ash and GGBFS is presented. The mechanical properties (compression, split tensile and flexural strength, bond strength) of geopolymer concrete at different mix proportions and at dissimilar curing conditions were also investigated. Geopolymer concrete synthesized with 30% fly ash and 70% GGBFS has better properties at 14 M of NaOH and cured in an oven for 24 h at 70 °C.