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Concrete is by far the most used building material in the world, but is facing a large environmental challenge due to its cement content. The production of portland cement is responsible for 5 to 8% of worldwide CO2 emissions. Waste and supplementary cementing materials (SCMs) such as blast-furnace slag can be used as partial or total substitute for portland cement to avoid or to reduce this negative effect. This work explores the study of durability and the mechanical behavior of concretes using urban and industrial waste glasses as a potential alkaline activator for slag (AAS).
The development of strengths and microstructure in the concretes activated with waste glass were also comparable to the parameters observed in AAS concretes prepared with conventional activators. Durability tests, including chloride penetration resistance, freezing-and-thawing resistance, carbonation, resistivity, and porosity, were conducted and the effect of the different parameters such as the activator type is discussed.
Keywords: alkali-activated slag; alternative alkaline activators; durability; waste glass.
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INTRODUCTION
Concrete, due to the large amount produced per year (over 9 billion tonnes [10 billion tons]) and its excellent mechanical properties and durability, is considered the most important material in the construction industry. However, the popularity of concrete has a notable associated drawback: its large environmental impact from the use of raw materials from quarries, the high energy demand in the process of clinker production, and because of the emission of greenhouse gases into the atmosphere (mainly CO2), globally estimated to be around 8% of all such impact.1 Reducing this problem is increasingly important, so in 1987, the term "sustainable development" was coined to describe the balance between technological development and conservation of the environment. Sustainable materials can be developed through several means, such as maximizing concrete durability and the use of waste and supplementary cementitious materials (SCMs). Fly ash, blast furnace slag, silica fume, and rice husk2 are waste materials that can be used as partial or total substitutes of portland cements, improving the durability of concrete and minimizing the environmental impact in the process of production.
Blast-furnace slag (a by-product of the steel industry) has been used as a cementitious material since 1774.3 Due to its latent hydraulicity, blast-furnace slag has been used as a partial replacement...