| With the development of construction industry, concrete admixtures have been the fifth necessary component of new type concrete. They can improve the durability of concrete. At present, although the research and using of admixtures have got larger achievement, many problems of admixtures, such as: basic research, development and applicational technology are needed to dicuss deeply.Considering the frost resistance to be one of the most important parts in field of concrete durability. Two agents of concrete: air-entaining agent and anti-freezing agent are successfully introduced to improve frost resistance, the basic properties of them and some performances of concretes with and without such two agents are presented separately in this paper, such as workability, mechanical properties, frost resistance, etc. In this test the author uses tools of infra-red spectrogram and scanning electronic microscope (SEM) to analyse, discussing mechanisms of air-entraining agent and anti-freezing agent in details finally.The experimental results show that the air entraining agent is a compound and non-iron agent, but its component is singular, it has good air entraining and water reducing, avoiding the physical blend of air entraining agent and anti-freezing agent simply.the air entraining agent not only introduce lots of fine, symmetrical, steady and closed air bubbles into concrete, but also decreased the produce cost. With the case of large water to cement, it can improve the pore structure inside concrete, enhancing the frost resistance obviously.Besides; the anti-freezing agent in this paper is a compound. The results show that new type anti-freezing agent can be used below -20℃. Each component of it can work available together and improve the construction properties of concrete in winter. |
