The Applications Research Of Flexible Cement Concrete For Pavement Of Highway Tunnel

Based on the analysis of the conflict between special application environment and the need of construction, fireproofing security, riding comfort, durability in highway tunnel pavement, this paper adopts complex modified and fiber reinforced technique to Cement Based Materials, and a low modulus and high toughening flexible cement concrete (FCC) pavement materials could be explored, which not only have common concrete advantages in construction, fireproofing security, durability, but also a equivalent riding comfort of flexible pavement materials.The way for FCC mix proportion design is discussed in the paper, then in view of the problem encountered in uniform-design result handling when there is no enough tests, a method of improved grey relational analysis is also introduced, and it is applied to analyze how the concrete mechanics properties is influenced, the analysis demonstrated that in terms of the fifth mix proportion, by moderately increasing Polypropylene, polymer fiber and Powder, considerably adjusting Bentonite, and optimizing the mix proportion, we can farther decrease the compressive modulus on the premise of necessary bending and splitting strength. Then the microstructure and modified mechanism also are discussed.In line with the pavement structure function theory, a new complicate pavement including layered steel fiber reinforced concrete and flexible cement concrete (LSFRC-FCC) is introduced. Its finite element modeling analysis showed that, flexible concrete layer have a diffusing effect to load, and with the FCC compressive modulus' improvement, there is sharp decrease on LSFRC board stress, pavement biggest displacement, and subsequent riding comfort, and some increase in FCC stress and pavement carrying capacity. The analysis also indicated that FCC lesser thermal conduction augmented its inner temperature grads, which aggrandize subsequently FCC layer temperature stress head and shoulders above it in LSFRC. In a word, FCC showed a good meet to tunnel pavement application need in the pavement design example.