Study On The Flexural Properties Of Foamed Concrete

Energy saving and environmental protection has become a major theme of the social development, areas of the construction industry as a waste of resources to the hardest hit, the development of new materials without delay. In recent years, as a new efficient and environmentally friendly building energy saving material, foamed concrete has been extensively studied and applied. With the application of foamed concrete, the flexural strength is widely used as an important index to measure the strength of concrete. However, due to the low density of foamed concrete, and the characteristics of many pores, the anti fracture strength is generally low, so that the index is not included in the industry standard "Foamed Concrete" JG/T-2011; how to further improve the flexural strength of foam concrete, so as to make it more widely used in the construction field, the problem is to be solved urgently.This paper uses hydrogen peroxide prepared by chemical foaming of foamed concrete,firstly, through the experiments to explore the impact of raw materials in powder dosage,water cement ratio, hydrogen peroxide content on flexural strength of foam concrete, the main rules determine the flexural strength of reinforced foam concrete, and find out the optimum dosage; secondly, through study on the different elastic modulus of fiber(polypropylene fiber,glass fiber) with complex influence on foam concrete flexural strength, get the general rule of fiber reinforced foam concrete performance change, so as to find out the other properties of foam concrete under the premise, the best way to increase the flexural strength; finally,combined with relevant standards and related the test, based on the flexural performance of foam concrete, summarizes the evaluation index for hydrogen peroxide foam foam concrete,and expounds the practical significance of the index.The results of study show that in the raw materials, when water cement ratio was 65%and foam concrete 28 d flexural strength reached the maximum 0.4MPa and the slump for217 mm, with good work; when crumb rubber content is 0.6%, foam concrete 3d and 28 d flexural strength reached the maximum value, respectively 0.42 Mpa 0.47Mpa; hydrogen peroxide content determines the foam concrete foaming degree and dry density of grade, when hydrogen peroxide dosage is 6% ~ 8%, the stability of foam concrete good, anti fold strength respectively, up to 0.51 Mpa, 0.46 Mpa, 0.26 Mpa.In fiber reinforced foam concrete, the flexural strength of foamed concrete is reduced.when the volume fraction of polypropylene fiber is 0.12%, the flexural strength of foamed concrete is enhanced, the effect is more obvious. When the content of hydrogen peroxide is 0.18%, the flexural strength of foamed concrete is increased by 28.4%; Theflexural strength of the foamed concrete is improved, the volume fraction of polypropylene fiber is 7%, the volume fraction of glass fiber is 0.06%, the flexural strength of foamed concrete reaches the maximum 0.68 Mpa.The study also showed that the effect of fiber content on the dry density of foam concrete was small, and the size of dry density of different mixing ratio was 6%. The addition of fiber can decrease the thermal conductivity of foamed concrete, increase the amplitude of2.8%~10.8%, and decrease the water absorption of foamed concrete. When the fiber content is0.06%~0.24%, the water absorption rate increases by 14.5%.Using the method of single factor analysis, this paper makes a comprehensive analysis of the raw materials and reinforced fiber of foamed concrete, and obtains the growth law of the anti fracture strength of foamed concrete, and also the other properties of the foamed concrete.