| Building energy efficiency is an important component of energy conservationand emissions reduction strategy in China, research and development of newenergy-saving building materials is one of the important direction. In this paper,starting from the formula design of foam concrete, having research of lightweightenergy-saving performance and mechanism of foam concrete systematically.According to the national and industry standards, the development of foam concretepouring technique in fiber foam concrete and ceramsite foam concrete has importantpractical significance to the building energy conservation. To this end, this paper hasdesigned the foam concrete formula firstly, and then on the basis of the formula withdifferent particle size of ceramsite and different specifications of the polypropylenefiber. Having measured its compressive strength, flexural strength, thermalconductivity and bibulous rate. The products are characterized by XRD and SEM.With the works above, the main results are as follows:(1) The validation and design of basic foam concrete in formula. Compared withordinary concrete formula, water cement ratio of0.4~0.45, level of700kg/m3density foam concrete formula has designed. The influence caused by the replace rateof fly ash and dilution rate of the foaming agent has been focused. Experimentalresults show that when replace rate of20%of fly ash, the dilution ratio of1:40, foamconcrete has the highest strength.(2) Based on the basic foam concrete formula, ceramsite with particle size of5to10(A) and10to15(B) has been added. The ceramsite foam concrete on density levelof700kg/m3has been prepared. The influence caused by dosage and grading ofceramsite has been examined. Experimental results show that when the dosage ofceramsite is180kg/m3, grading A: B is4:6, the compressive strength on28d is3.7MPa, is better than that of the density level of national standard regulations on2.0MPa. Flexural strength on28d is0.73MPa. Thermal conductivity is0.143W/(m K),which is better than the density level of national standard regulations on0.18W/(m K). (3) The formula on density level of400kg/m3of foam concrete has beendesigned. The influence on the performance of foam concrete, which is caused bypolypropylene liner fiber and polypropylene mesh fiber with different length anddosage, has been investigated. The experimental results show that compared with theblank, the maximum water absorption of polypropylene liner fiber has increased by1.72%, while the polypropylene mesh fiber has increased by1.09%. Both of themhave reached the national level of W40. The performance of foam concrete with twokinds of fiber reached the max when the dosage is2kg/m3, the length is6mm. Andthe polypropylene liner fiber is better than polypropylene mesh fiber in theperformance of mechanics performances. At this point, the sample with polypropyleneliner fiber of compressive strength on28d is0.9MPa, while the other is0.85MPa.Both of them have reached the national level on0.5~1.0MPa. The flexural strength ofpolypropylene liner fiber on28d is0.19MPa, and the other is0.185MPa, The thermalconductivity of polypropylene fiber is0.083W/(m K), better than that of the densitylevel of national standard regulations0.1W/(m K).(4) An analysis of the SEM and XRD characterization of products showed that,incorporating ceramsite or fiber has no significant effect to the chemical compositionof foam concrete. The fly ash in ceramsite group has been activated by curing agent,having participated in the gel reaction. It can be clearly see that the combination ofpolypropylene liner fiber and foam concrete is better than that of polypropylene meshfiber in fiber group.
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