Abstract: Alkali-free or low-alkali liquid concrete accelerator has been going to replace the traditional accelerator by its excellent performance, and to become the representative of new accelerator. In order to better understand the research progress of alkali-free or low-alkali liquid accelerator, we presented the products, performance characteristics, and the accelerating mechanism of new accelerator, and analyzed  the existing problems in its adaptability, stability, accelerating mechanism, products and price,  reasonable dosage, and application quality control. We also discussed directions of further researches in this aspect.              

Key words: accelerator, alkali-free, low-alkali, accelerating mechanism, research progress