Experimental Research Of Polypropylene Fiber Reinforced Rice Husk Mortar External Wall

Bar-Reinforcing-Net sandwich concrete external wall has been applied in prefabricated construction within a certain extent on account of its properties of high strength,low price,row material obtained easily.However,in the steel frame prefabricated constructions,the application of Bar-Reinforcing-Net sandwich concrete external wall has been limited largely because of its other properties of large mass,low ductility,poor crack resistance and impermeability.In this paper,aiming at the problem of large mass,poor crack resistance and impermeability performance of that external wall,the fine stone concrete is replaced by polypropylene fiber reinforced rice husk mortar,the material experiment of polypropylene fiber reinforced rice husk mortar is conducted and the flexural property of polypropylene fiber reinforced rice husk mortar external wall is researched.The main contents include:(1)the 28 days compressive strength test,the 28 days flexural strength test,the early shrinking crack test and the permeability resistance test will be carried out by adding polypropylene fiber with different volume dosage(0.05%,0.10%,0.15%)and different fiber length(6mm,9mm,12mm)into rice husk mortar.The results show that the polypropylene fiber reinforced rice husk mortar with 0.05% volume dosage and 6mm length has the highest compressive strength,flexural strength,water seepage strength which improves one impermeability grade compared to the fine stone concrete and the minimum of shrinkage crack area,its crack resistance performance is the best.compared to larger length and large volume dosage,the crack resistance and anti-seepage performance of small length and low volume dosage of polypropylene fiber reinforced rice husk mortar are better,the influence of polypropylene fiber on the compressive strength is not significant.(2)It is necessary to detect the elasticity of the polypropylene fiber reinforced rice husk mortar with 6mm length and 0.05% volume dosage.the results show that the axis compressive strength standard value equals 14.64 MPa,the axis compressive strength design value equals 10.46 MPa,the elasticity is 18000 MPa.(3)In order to study the flexural property of polypropylene fiber reinforced rice husk mortar external wall(hereinafter referred to as the "external wall"),the full-scale specimen of external panel is made and the flexural bearing capacity experiment is performed in the test room.the results show that when the cracks appear obviously,its vertical displacement deformation is about 6mm,cracking load is 2.6 KN/m~2,the failure load is 2.6 KN/m~2,the maximum strain value is 657 and the largest displacement is 10.557 mm.with comparison of the nationwide largest wind load design value of 2.649 KN/m~2,it is reliable for the external panel to resist the horizontal wind load function and meet use requirements.(4)finite element numerical simulation analysis of the window-opening external panel and non-opening external panel is carried out.Results show that there is similar flexural bearing capacity between the window-opening external panel and non-opening external panel,but the rigidity of the window-opening external panel decreases relatively.