Preparation And Experiments Properties Study Of Modified Fiber Reinforced Polymer Cement Mortar

Cement mortar, as a kind of common cement concrete structures of bonding and repairing material, has its unique advantages, such as low cost, durable, security and stability, etc., It is widely used in buildings, Bridges, roads and other application. But in the ever-changing modern society, the ordinary cement mortar has been difficult to meet the requirements of all kinds of engineering for its different performance.In order to improve the defects of ordinary cement mortar, such as brittleness, poor deformation ability, tensile and bond strength lower, in order to make it have more abundant practical performance, a lot of work have been done by many scholars to enhance and improve the performance of the cement mortar, such as mixed with different kinds of polymer and fiber to modified the cement mortar is of great significance to improve and enhance the performance of the cement mortar.Based on the properties mentioned above this article put emphasis on hydrophilic modification of polypropylene fiber (PP fiber) surface and the mixing with polymer powder effect on the properties of cement mortar.The main research contents include:(1)According to the application place of cement mortar choosing the raw materials;(2)Using light calcium carbonate coated PP fiber on the surface of hydrophilic modification, observeing the distribution of light calcium carbonate particles coated on the surface of PP fiber by scanning electron microscopy (SEM) and by observeing the dispersion of the modified PP fiber in the water to characterise the modified PP fiber;(3)Based on the mechanical properties of cement mortar indicators, determining the water cement ratio,the appropriate mix content of the polymer powder and PP fibers by contrast test and select the best matching;(4)On the basis of the best proportion of PP fiber reinforced cement mortar, using the modified PP fiber to replace the ordinary PP fiber, and the study of the influence of modified PP fiber and modified PP fiber mixed with polymer powder to mechanical properties of cement mortar;(5)Based on the mechanical properties of cement mortar, this paper also studied the different lengths of PP fiber, different length of poly (vinyl alcohol) fiber (PVA fiber) and different lengths of the two fiber hybrid on the mechanical behavior of cement mortar, and choose the optimum fiber length and hybrid fiber length, on the basis of adding polymer powder, the influence of different length and different types of fibers mixed with polymer powder to mechanical properties of cement mortar;(6)SEM microscopic analysis was carried out on the cement mortar specimens, and compared different magnification SEM photos of the fracture morphology of cement mortar, the distribution of fiber and modification of PP fiber and polymer cement powder cement matrix form;To focus on analysis of the enhancement mechanism of mechanical behavior of cement mortar after adding modified PP fiber mixed with polymer powder.In this paper, the conclusions are:(1) the suitable ratio of fiber and polymer modified cement mortar for:plastic sand ratio of 1:2, water cement ratio 0.30, fiber dosage is 2 kg/m3, the content of the polymer powder is 1% of the cement quality, dosage of water reducing agent of 1% of the cement quality, defoaming agent content of 1% of the cement quality;(2) of the modified PP fiber with good hydrophilicity, can be evenly dispersed in water, no floating, no clouds;The use of the modified PP fiber instead of ordinary PP fiber mixed with polymer cement mortar, can obviously improve the bonding performance of fiber and cement matrix, and improve the flexural strength and toughness of cement mortar;(3) within the scope of a certain length, the proposal USES fiber length is 15 mm;Different lengths of PVA fiber blend does a certain influence on the strength of the cement mortar, of which 18 mm 3 mm and the hybrid way to get the highest strength;(4) of the different length of PP fiber and PVA fiber blend has a certain influence on the strength of the cement mortar, the length is 6 mm of two kinds of fiber blend the strength of the specimens were relatively high.