Properties Research On Pre-placed Recycled Brick Aggregate Concrete By Grouting With Foam

Along with the continuous development and utilization of resources, how to make rational use of existing construction waste, turning waste into treasure, become problems to be solved in the road of sustainable development. At present, in the aspect of resource utilization of construction waste in China, the research on waste concrete as recycled aggregate is more than the research on waste brick as recycled aggregate. The research on combining with the advantages of recycled brick aggregate concrete and foam concrete is least. In our country, the abandoned concrete and brick have been accounted for about 80 percent of construction waste. If this part of the construction waste can be effective utilized, it can improve the rate of utilization of construction waste.In this paper, all of the abandoned brick after crushing, washing, screening are used as recycled coarse aggregate,100% instead of natural aggregate to make medium and low strength concrete. In order to simplify the construction process, the technology of preset recycled brick aggregate grouting is adopted. While making full use of the thermal insulation property of clay brick, adding foam to the grouting slurry, to further reduce the thermal conductivity of concrete. The aim is to provide a kind of concrete of energy conservation and waste utilisation,which has heat preservation, heat insulation and load-bearing properties.Firstly, The strength comparison of pre-placed recycled brick aggregate grouting concrete with different gradation is carried out through the experiment.And each factor affecting the fluidity of grouting slurry is studied quantitatively.They prove the aggregate gradation range of recycled coarse aggregate and the range of the content of each component in the grouting mixture. The recycled brick aggregate concrete specimens are made by grouting method. The influences of recycled coarse aggregate volume ratio, water-cement ratio, the substitution quantity of fly ash and foam content on cubic compressive strength, splitting tensile strength, dry density and water absorption rate of pre-placed recycled brick aggregate concrete by grouting with foam are studied. So as to determine the best content of different raw materials.Then, according to the results of single factor test, the optimum mix proportion of pre-placed recycled brick aggregate concrete by grouting with foam is obtained by using the orthogonal test method. The cubic compressive strength, axial compressive strength, splitting tensile strength, elastic modulus and stress-strain curve of concrete specimens with different foam content are tested. The relation formula between the cubic compressive strength, axial compressive strength and splitting tensile strength are established from the analysis of test data of basic mechanical properties. At the same time, the thermal conductivity of concrete is mearured. Under the optimum mix proportion, the thermal conductivity is less than the thermal conductivity coefficient of clay brick and ordinary concrete. It has good heat preservation effect.Finally, application of concrete is studied. A new wall system of semi industrialized production medium sized block based on the strengthening system of card fixed type reinforcement mesh has been put forward which is between the pure rural manual masonry and prefabricated building of city. It speeds up the construction progress, achieves semi assembly of construction and greatly reduces the cost. The practical construction key technolpgy is given for the rural masonry structure.