| Concrete is one of the most important materials in the world of which the used amount and application range is the largest. It is an indispensable material base in the civilization of human. More and more roller compacted concrete(RCC) is used in hydraulic engineering and road engineering as a kind of special concrete. RCC is a kind of super hard drying concrete which is formed by vibration roller. It is used for damming works in hydraulic engineering. Humman find RCC has many advantages as the development of roller compacted concrete technique, such as rapid construction, high strength with less cement and low hydration heat which could meet the requirement of low hydration heat when the mass concrete is pouring. Due to so many advantages, RCC has been usd in road engineering gradually, which is named roller compacted concrete pavement(RCCP). The main construction machineries of RCCP are the same as them used in asphalt concrete pavement.Though there are many advantages when RCC is used in road engineering, there are many defects too. Firstly, due to the low cement content, the strength of RCC is not high enough, so RCCP would be destroyed easily after roller compacted by heavy duty automobiles again and again.Secondly, RCC has the same defects as common concrete, such as bad toughness and low tensile strength. In addition, under the effect of vibration roller, there will emerge ultrasonicexamination, and cement slurry gathers on the surface of the RCC. These phenomenons would reduce anti-slide performance, increase noise in the tunnel and decrease the wear resistance of the pavement.The main purpose of this paper is to solve these problems, so as to improve the construction quality of RCC. This paper mainly study on the followed three aspects.In order to solve the problem that the strength of RCC isn’t enough, this paper adopts the method of orthogonal optimum design, choose four elements include water cement ratio, cement consumption, silica fume dosages and water reducing agent dosage. Every element has three levels.In order to solve the problem that the toughness of RCC is bad, this paper used steel fiber to renforce RCC. Based on the study on how the different mixing amount of steel fiber influence the compressive strength and splitting tensile strength of RCC, so as to improve the service performance of RCCP.In order to solve the problem that both the anti-slide performance and noise reduction performance are bad, this paper used exposed-aggregate technology in RCCP, and obtained exposed-aggregate RCCP. According to the study on how different concentration of exposed aggregate agent influences the depth of exposure, this paper could choose appropriate concentration of exposed aggregate agent. Furthermore, this paper has studied on the matched technology of exposed-aggregate RCCP which is the time that the cement slurry on the surface of the RCCP is washed after the exposed aggregate agent sprayed.Base on these studies, this paper obtains high strength RCC, the strength is up to 64.44MPa. Then according to variance analysis, this paper finds that the most important elements that influence the strength of RCC are water cement ratio and cement consumption. And this paper obtains regression equations of 7-day strength and 28-day strength with the way of orthogonal regression analysis. Secondly, this paper improves the splitting tensile strength of the RCC significantly through steel fiber reinforced RCC. Lastly, this paper used exposed-aggregate technology in RCCP very well, obtained exposed-aggregate RCCP of which the depth of exposure is between 2mm and 3mm, and developed matched technology of exposed-aggregate RCCP which are the best exposed aggregate agent concentration and washing time.In a word, according to the study of this paper, it is likely to overcome the defects of RCC, and give full play to the advantages of it. This is beneficial to the application and promotion of RCC in road engineering. |
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