Experimental Study On Water Absorption Of Polypropylene Fiber Concrete

Own feature makes the concrete structure in service stage is often work with cracks,polypropylene fiber concrete can effectively prevent the formation of the internal and surface cracks and launching,avoid water on the interface and the cracks,avoid the matrix transfer adverse influence on the durability of the concrete structure.Generally thought that,in the role of the load inside the concrete produce microfracture and a channel,water and other harmful medium through the channel to the interior of concrete material,concrete material degradation,durable performance degradation.Because concrete is a non-saturated building material,water is transmitted mainly by capillary water.Polypropylene fiber and cement base material mixture of composites is the polypropylene fiber concrete,the concrete can restrain concrete crack failure occur under the condition of stress,and prevent the harmful medium such as air,water infiltration,improve its durability,make its can adapt to different environment under the condition of special environment,for strengthening concrete structure provides a simple and fast way.Since the structure is generally subjected to long-term load during the service phase,the effect of load on the performance of concrete is more in line with the actual situation.This paper focuses on the study of water absorbent test for polypropylene fiber concrete in common stress condition,and the main work is as follows:(1)The design of five different volume content of polypropylene fiber concrete hollow cylindrical specimens,the compressive capacity and carries on the experiment,it is concluded that the different volume content of polypropylene fiber on compressive strength of concrete,and it is concluded that the ultimate compressive stress of specimen in each group,to explore different load levels after research provides the ultimate compressive load value of the specimen.Compared with plain concrete,the test results show that the polypropylene fiber concrete has not produce too much contribution to the compressive capacity of concrete,but as you can see,according to the specimen damage status compared with brittle failure of plain concrete,polypropylene fiber significantly increase the ductility of concrete.(2)With different volume content of polypropylene fiber concrete specimens in no load condition for water absorption test,analysis of test results,to explore the different fiber content of specimens,the effects of moisture transmission,and for the study of concrete under different load level,load way suction performance compared to the reference.(3)Water absorption test for polypropylene fiber concrete hollow cylinder,which is doped by different volume.Sustained load method,loading level respectively take its ultimate compressive load of 30%,50%,70%,by the different fiber content and the influence of different load levels,by Darcy extension theorem,the specimen suction height,bibulous rate per unit area were analyzed,and prove that adding polypropylene fiber to prevent concrete crack propagation in order to improve the water absorption of concrete performance;Through the contrast analysis of different dosage and different load levels specimen suction height,bibulous rate per unit area of change,explore the polypropylene fiber content,load level of concrete specimens,the effects of moisture transmission,and gives the optimal dosage of polypropylene fibre reference value.(4)Water absorption test for polypropylene fiber concrete hollow cylinder,which is doped by different volume.Load levels,respectively,take its ultimate compressive load of 30%,50%,70%,and the repeated loading to expected load level after unloading the way to zero,water absorption test was carried out on the specimen,influenced by fiber content and load level,the absorbent of specimen a non-linear regularity of change,through contrast experiment,the different load,load level,polypropylene fiber concrete specimen suction height,bibulous rate per unit area of rule changes over time.(5)For all through ballast water absorption test of the specimen,determine the residual compressive stress,the results compared with the initial ultimate compressive stress,and to explore the polypropylene fiber reinforced concrete under different loading ways(no load,the load,repeated loading after water absorption test of compressive stress,explore the polypropylene fiber to concrete compressive stress contribution degree after water absorption.