Effect of plasticizing admixtures on the performance of low-carbon cementitious systems

The article presents a comparative investigation of three generations of plasticizing admixtures – lignosulfonates (LS), naphthalen sulfonate (SNF), and polycarboxylate ethers (PCE) – in cement-sand mortars based on low-emission composite Portland cement CEM II/B-M(V-LL)-42.5R. The technological and technical effects of admixtures were evaluated. Testing was performed on standard sand according to DSTU EN 196-1 and quartz sand from the Mykolaiv quarry. The results showed that PCE provide water reduction of 25–30% and cone flow ability to 240 mm, while LS provides a moderate effect (flow ability 160–165 mm), and SNF provides an intermediate position with a pronounced dependence on Na₂SO₄ content. Among lignosulfonates, calcium LS demonstrated higher strength compared to potassium LS. The application of PCE in combination with composite cement provides a reduction in CO₂-intensity by ~14% compared to the control mix.