Sustainable construction in actions

 
Alkali activated materials have become increasingly popular as a supplementary cementitious material for ordinary Portland cement (OPC) given the increased societal attention to global warming. Ground granulated blast furnace slag (GGBFS) is such a typical industrial waste. Reuse in concrete production can lower the negative environmental impact and also reduce costs of discarding GGBFS. It could reduce the carbon footprint in a typical concrete mix design by ~ 22 %. Due to its latent hydraulic property, slag as a binder suffers from inferior rheological properties which prohibits the large-scale application of alkali activated slag (AAS). The use of superplasticizer admixtures offers a key to tackling the rheology problem for AAS. The dispersing performance of three PCE superplasticizers varying in macrostructures were investigated in AAS. Then, a correlation between the microstructure of the PCE polymers and the interaction mode with AAS was established. It was hoped that the findings from this study can help to understand which structural motifs are the most efficient in terms of fluidizing effect in AAS, i.e. to find a guideline for the design of novel PCE geometries.