萘磺酸系強塑劑混合羧酸系強塑劑添加入混凝土後工作性有明顯的變差，找出原因並改善此現象是本篇研究重點。本研究首先使用三種不同比例混合強塑劑劑量，分別為1:3、1:1、3:1。實驗得到當萘磺酸系比上羧酸系強塑劑為3:1時，有最差的水泥漿流度。
在3:1最差流度條件下，改變拌合水pH=4、7、10，研究結果顯示改變pH值對水泥漿的流度增加沒有明顯幫助。另外在一樣3:1條件下拌合水加入NaCl和CaCl2 結果發現有明顯的沉澱物質，而在相同鹽類濃度劑量下單一萘磺酸系強塑劑和羧酸系強塑劑的拌合水沒有任何沉澱，實驗結果證實混合強塑劑會受到鹽類濃度增加而發生鹽析現象，然而添加10mL的丙酮到已有沉澱物的拌合水就能有所減少因鹽析而變成混濁的水溶液濁度。
為了減少混合強塑劑受到水泥溶出的鹽類而會鹽析然後失去強塑劑的效能，使用5mL丙酮取代5mL拌合水，結果發現水泥漿的流度有明顯的增加，這就表示混合強塑劑效能會受到鹽析而變差。

Mixing the Naphthalene sulfonate-based superplasticizer and the carboxylic-based superplasticizer in concrete let the workability be obvious worse. How to resolve this phenomenon is an important topic to this research. In this research, the first to use three kinds of different combinative dosage of the mixed superplasticizer, respectively 1:3,1:1,3:1. The Naphthalene sulfonate-based superplasticizer compared to the carboxylic-based superplasticizer is 3:1,and then there are the worst cement paste’s fluidity.
In the worst-flow condition(3:1), the research results show that changing the pH value of water of increase in the flow of cement paste and there is no apparent help. In the same conditions(3:1), the mixing superplasticizer in the water which have the visional precipitation when add NaCl and CaCl2 in the water. But while the same salt concentration add in the pure Naphthalene sulfonate-based superplasticizer and the carboxylic-based superplasticizer, there are no precipitation in both water solution. The experimental results show that mixed superplasticizer solution will be salting-out when there is more salt concentration in the solution. But adding 10mL acetone in the solution, the turbidity of solution will become decreasing which the turbidity result form the precipitation.
To decreasing the salting-out result form the cement’s salt dissolving in the solution that can decrease cement workability.We replace 5mL water to 5mL acetone and the flow of cement paste is more increasing.This meaning that the workability of mixed superplasticizer is worse because of salting-out.

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