Abstract:

The compatibility of superplasticizer and cement with the same clinker but different particle size distributions （PSDs） was investigated via the Marsh cone method and the paste fluidity method, and the effects of the specific surface area of powders, the uniformity coefficient n, the characteristic diameter x′ and the packing porosity on the compatibility were analyzed. The results show that  the compatibility becomes poor with the increase of the specific surface area, n and the packing porosity, and with the decrease of x′;  when the specific surface area is approximately equal to x′, with the increase of n, the paste fluidity becomes poor, the saturation point dosage and the Marsh time increase, and the loss of fluidity with time reduces;  with the increase of specific surface area, the compatibility becomes poor, and the negative influence of specific surface area on the compatibility becomes critical at a narrow PSD;  low packing porosity may result in continuous and wide distribution of cement particles： and  powders with low water reqiirement are more suitable for imoroving the compatibility.

Key words: particle size distribution, compatibility, uniformity coefficient, specific surface area, Marsh time