Abstract:
Understanding how poly(carboxylate)s of chemical admixtures interact with calcium ions
in cement pore solutions in the presence of silica fume is fundamental to developing better chemical
admixtures for concrete production. In this work, the intermolecular interactions of calcium ions
with a poly(carboxylate) superplasticizer type of chemical admixture was investigated via classical
all-atom molecular dynamics (MD) simulations and Density Functional Theory (DFT) calculation
methods in the presence of silica fume. The classical all-atom MD simulation and DFT calculation
results indicate that calcium ions are interacting with oxygen atoms of the carboxylate group of PCE.
The better interaction energy could mean an improved adsorption of the PCE segment with calcium
ions. In this regard, it can be noted that the ester-based PCE segment could have a better adsorption
onto calcium ions in comparison with the ether-based PCE segment. Moreover, the presence of silicon
dioxide could improve the adsorption of the PCE segment onto calcium ions.
