Study On The Super-light Foamed Concrete Insulation Material

The foamed concrete is a kind of inorganiced insulation architecture material. Its main characteristic is light weight,good insulation,good fireproofing,and has been widely used in China construction . Among them, super-light foamed concrete (with density less than 300kg/m3) is used as a leader in insulation materials ,because of its excellent performance.However, this kind of insulation material is mostly made of special cement ,for example the sulphoaluminate cement. It brings two questions:First of all, the durability of the foamed concrete is very poor; secondly, compared with the ordinary cement , the cost of special cement is higher. All of these hindered the further development of the insulation materials which was made of special cement. In order to solve this problem, in this research ,the super-light foamed concrete insultion material was producted by portland cement.The paper studied the sodium aluminate,lithium carbonate,KW and anhydrous sodium sulfate effect on the mortar coagulate which is composed by portland cement and FA firstly .Test results showed that among the four types of coagulants, lithium carbonate was the best,and its appropriate content was about 34 percent(compared with the quality of cement). When the quality of cement and fly ash ratio was 0.4,studied the relation between the water ratio,the content of foaming agent,the type and content of foam stabilizer,polypropylene fiber content,sepiolite,slurry temperature,mixer speed and the concrete basic performances.The results showed that the best raw materials mix for madding the super-light foamed concrete was when the feed ratio of water was 0.54,mixing0.34% lithium carbonate 0.30% foaming ability agent,4.8% -5.1% foaming agent,1.2% polypropylene fiber (accordance with the quality of cement.And the best technology condition is : the slurry temperature is 27℃-29℃,mixer speed was 2500r/min. Under this condition, the main performances of the super-light foamed concrete were :the lowest density of the product was 279kg/m3,28d compressive strength was 0.51Mpa,thermal conductivity was 0.068W / (mK),the quality of the water absorption was 48%.Compared with the similar market products, all performances of the DIY super-light foamed concrete were significantly better than the market products. Then studied the pore structure of the super-light foamed concrete with the modern testing technology, made a simple analysis between the pore structure and the performances of the foamed concrete. Explained the mechanism about how the polypropylene fiber effect on the super-light foamed concrete from the point of micro-analysis,such as the pore structure and hydration products. The results of the study had a role of guiding the production of product the super-ligh foamed concrete with ordinary portland cement .