Stimuli responsive workability retention of cement paste containing polycarboxylate superplasticiser

摘要

Polycarboxylate superplasticisers (PCE) were synthesised and their structure was characterised by Fourier-transformed infrared spectroscopy. The simulated physiological environmental effects on the workability retention of cement paste containing PCE were studied; that is, stimuli response to sulfates by measuring the fluidity, water-reducing ratio, compressive strength and setting time. The fluidity and water-reducing ratio of cement paste containing PCE with a long chain weakly depended on the salt dosage, but properties of compressive strength and setting time were strongly influenced by the salt dosage. However, the fluidity, water-reducing ratio, compressive strength and setting time of cement containing PCE with both long and short chains were strongly influenced by alkaline sulfate. PCE with a long side chain has a good compatibility with cement paste. The ionic responsive properties are attributed to the change of the PCE adsorption ratio, which results directly in a variation of the dispersing force of superplasticiser.