Alkali-activated binders: A review

Abstract

The disintegration of concrete structures made of ordinary Portland cement (OPC) is a worrying topic of increasing significance. The development of new binders with longer durability is therefore needed. Alkali-activated binders have emerged as an alternative to OPC binders, which seems to have superior durability and environmental impact. This paper reviews current knowledge about alkali-activated binders. The subjects of Part 1 in this paper are historical background, terminology and hydration products. The proper terminology to designate these new binders will be discussed. The influence of the prime materials and the type of alkaline activator on the reaction mechanisms and on the nature of the reaction products will be described.

Assessing the chemical involvement of limestone powder in sodium carbonate activated slag

“…Alkali activated materials (AAM) have been attracting worldwide attention during the last few decades because of their good material properties and environmental benefits [1]. Nevertheless, depending on the used raw materials and alkaline solutions, the performance of the resulted materials can be varied [2,3].…”

“…However, the function of LP on the reaction of alkali activated materials has not been systematically studied yet. Up till now, only limited efforts [17][18][19] have been devoted to this topic partly because the system of alkali activated material (AAM) is more complex than Portland cement system due to the different activators and raw materials applied [1,20,21].…”

Review on Potential of Geopolymer for Concrete Repair and Rehabilitation

“…Chemical products are also used to increase the substrate surface roughness. Pacheco et al [9] mentioned an acid etching method is used to prepare the bond surface, but carefully washed is required to ensure the removal of CaCl 2 which results from the reaction between HCl and Ca(OH) 2 Smooth as-sawn, wire-brushed, hand-chiselled, and acid etching were used in order to prepare the surface of old concrete samples. Acid etching is the best.…”

“…Some researchers normally will investigate and make a comparison between geopolymer mortar and commercial products [8][9][10][11]. Slant shear test is one of the approached method highlighted by the previous researchers in order to evaluate the performances of the repair material [12].…”

EDS-Based Phase Analysis of Alkali Activated Slag

“…The second one is the alkali activation of natural aluminosilicates such as metakaolin with medium to high alkaline solutions. Alkali-activated materials have been known as an alternative to Portland cements due to the higher compressive strength (exceeding 100 MPa in 28 days), durability and environmental benefits [1,2]. However, to understand the development of mechanical strength and durability, an understanding of the phase formation and chemical composition of these phases it required.…”