Application Of Fiber Brucite Reinforced Concrete In Highway Engineering

Cement concrete pavement is an important structure form of highway. Compared with asphalt pavement, cement concrete pavement has the advantages of long service life, less maintenance workload, less energy consumption, easy to construct and easy to adopt the traffic rank and the environment, etc. But due to various reasons, the using situation of China's early built cement concrete pavement was not well, its service life was greatly lower than the limit of the designed using years. Especially in some cement concrete pavements with heavy traffics damaged seriously in the early years, often seriously damaged in 2～5 years after beginning the traffic and produce the structural damage of broken board, broken horn and shatters, etc. The damage of the cement concrete pavement are caused by many reasons, one of the main causes is the brittleness of the concrete material. Adding certain proportion fiber into concrete, namely fiber reinforced concrete, is an important measure to improve the brittle of concrete.The paper using brucite fiber mixing into cement concrete, as a new kind of concrete pavement materials, design appropriate brucite fiber mixing proportion into concrete pavement, and make it better applied in the usage of road construction. It researches system on the properties and the influencing factors of the brucite fiber reinforced concrete material, and through the indoor laboratory test, the proportion design of brucite fiber reinforced concrete were studied. On the base of laboratory studies, and according to the standard proportioning design of cement concrete pavement materials, carry out the site lab test and introduce the engineering mixture, Finally, according to the performance of the scene material, go on the conversion of engineering construction, and according to the constructional technical specifications pave the test pavement.The indoor lab test results showed that mineral admixture brucite fiber reinforced concrete can improve the flexural tensile strength of concrete. Between the dosage of fiber cream and water-cement ratio there are the highly significant negative correlation relationship and have significant linear relationship between the dosage of fiber cream and slump. When the dosage of fiber cream increases, the water decreases, and the slump increases. Between the dosage of cement and fiber cream and the compressive strength of brucite fiber reinforced concrete there are the remarkable linear relationship. When the dosage of cement and fiber cream increases, the compressive strength of concrete also increases when the slump increases. There are also highly significant linear relationship between slump and the compressive strength of brucite fiber reinforced concrete, the strength of concrete increases when the slump increases.Research on laying of Road show that:The test section of TongChuan rural highway fall the cement grade, using the low grade of PC32.5 cement; the consumption of cement down to 186Kg/M3, the total amount of gel material has only 305Kg/M3, that is significantly reduced compared with ordinary rural roads amount of cement 380kg/M3. The mechanical properties of concrete construction fill the order of design, flexural strength of 5.0MPa or more; concrete cost reduction, as compared with ordinary rural roads reducing the cost per square concrete 5-10 dollars. The test section of Blue line highway fall the cement grade 52.5 by the off-line number dropped to 42.5 number, cement consumption decreased by the well-off line 387Kg to 367Kg; fiber content further reduced from 15.6Kg to 14.7Kg; further improve the strength of concrete,28d flexural intensity nearly 10MPa; The cost of material fall lower, to about 353 Yuan per square concrete less than 33.3% of steel fibers.Through the comparison with ordinary cement concrete test and economy analysis, the conclusion:compared with ordinary cement concrete, brucite fiber reinforced concrete increase the flexural tensile strength and reduce the rigidity, increase the toughness, improve the fatigue resistance and, impact resistant, the properties of resistant frost, antiseep, wear-resisting, corrosion resistant are also improved in certain amplitude. Because of the preparation of fiber cream simplified the construction process of the fiber reinforced concrete, the construction process of the pavement between brucite fiber concrete and the ordinary cement concrete are almost the same, after the pavement engieering test, the application is good. From the angle of economic analysis, brucite fiber reinforced concrete pavement cost slightly higher than cement concrete pavement, the average cost per cubic meters of it is about 1.02 times of the equivalent of common concrete pavement, but its performance is 1.42 times of concrete pavement. It shows that brucite fiber reinforced concrete pavement has very good economical and application prospect.