Experimental Study On Performance Of Straw Fiber Reinforced Concrete Block Masonry

In addition,because of lots of old buildings' useful life is coming and to meet the need of development of the Urban Planning.The old buildings must be dismantled and reconstructed.As a result a lot of building waste will come out.This would bring some grave consequences,such as environmental pollution,occupation of land and so on,if we can not treat building waste well.Meanwhile,on account of the large quantities of building,the resource exhaustion is coming.So how to achieve the effective use of the abandoned concrete in new building without reducing the performance of structure to meet the demand of Green Building.It has been the immediate research focus.At present,most of the cold regions of China by building exterior wall insulation form,this form has many disadvantages,the biggest disadvantage is that the external wall thermal insulation material life for 25 years,the building itself is far lower than that of 50-100 years of life,resulting in external wall insulation systems generally require two maintenance;second exterior insulation materials because of their own reasons,a fire safety hazard because of the large exterior insulation system.Therefore,there will be a new type of thermal insulation to replace the external insulation,so the external wall insulation system has emerged.According to the present situation and building energy-saving wall insulation materials requirements,this paper proposes the use of fly ash,straw fiber as the main material,adding high foaming agent by mechanical mixing method,natural curing developed a meet the energy requirements of the insulation material of straw fiber reinforced fly ash foam concrete.The research methods and results of this study are as follows:(1)To determine the mix proportion of straw fiber fly ash self insulation foam concrete.Straw fiber and fly ash were used as the main variables,and the content of fly ash was 35%,40%and 45%,respectively.The content of straw fiber was about 0,1%,and 2%respectively.By comparing the concrete compressive strength,dry bulk density and dry shrinkage,the optimum mixing ratio for straw fiber content is 1%,the amount of fly ash is 40%,the self strength of insulation foam concrete to more than 5.0Mpa,the density is 916kg/m3,A05,B09 foam concrete.(2)Study on the performance of straw fiber fly ash self insulation foam concrete block.In the best mix proportion of size density,compressive strength,flexural strength,thermal conductivity,frost resistance and the quality of water absorption properties of the foamed concrete block 600×240×200 dry experiments were carried out according to the standard,the performance of foam concrete block can meet the "requirements of JC/T1062-2007 foam concrete block".It can be seen that the mechanical properties and thermal properties of foam concrete block are good.(3)ANSYS finite element thermal analysis and mechanical analysis of straw fiber fly ash self insulation foam concrete block.In the thermal analysis,the temperature field distribution and the heat flux distribution of the block are analyzed.It is found that the temperature distribution is uniform and the temperature cracks are not easy to occur.(4)Study on the basic mechanical properties of straw fiber fly ash self insulation foam concrete block masonry.By using the block size of the main block of the building block and the auxiliary block of the half block,three blocks of masonry are made,and the axial compressive strength and the shear strength of the joint are tested.It is concluded that the axial compressive strength and the shear strength along the joint are in accordance with the requirements,which provides the basis for the promotion of the straw fiber fly ash self preservation foam concrete block.The test results of straw fiber insulation foam concrete has good mechanical properties of straw fiber fly ash self insulation foam concrete block,the strength can reach above 5.0MPa,good insulation properties,thermal conductivity is 0.19W/(m · K),good frost resistance,after 15 cycles of quality and strength comply with frost resistance requirements in cold area.The utility model can be popularized and used in the cold area,and is a straw stalk fiber self insulation foam concrete block which integrates the bearing and heat preservation.But in the process of masonry block insulation mortar should be used,so as to ensure that the insulation of the wall;in addition to other properties of the block need further research,such as impermeability,carbonation coefficient and so on,in order to promote the use of straw fiber fly ash self insulation foam concrete block.