دانلود رایگان مقاله انگلیسی مطالعه کاربرد فیبر بتن آرمه در مدخل آبگیر - الزویر 2018

abstract

A sluice gate is a primary hydraulic structure in water discharge and storage facilities. Steel sluice gates are often stolen when global metal prices are high. Thus, this study proposed using fiber-reinforced concrete to fabricate sluice gates. The material mechanical properties and durability of the fiber-reinforced concrete sluice gates were tested, and field test and feasibility tests were subsequently performed. The compressive strength, flexural strength, and elastic modulus of the concrete used to construct the gates were respectively 99.3 MPa, 18.2 MPa, and 40.0 GPa. In the concrete, the depth of wear by hyperconcentrated flow was 0.5 mm h1 mm2 ; the chloride diffusion coefficient was 2.25  1012 m2 s1 ; and the weight loss in the soundness test was 1.02%. The results of the field testing suggested that the size and weight of the fiber-reinforced concrete sluice gates met operational needs and that the gates maintained their watertight seals and functioned normally during and after several tropical cyclones. Monthly observations revealed no noticeable cracks or rust stains on the gate surfaces. And the difference of properties of fiber-reinforced concrete before and after one year exposure is within ±6%. The fiber-reinforced concrete sluice gates were estimated to be one-tenth cheaper to produce than stainless steel gates and one-fifth cheaper than cast iron gates. The concrete sluice gates can be employed in low-head areas and drainage basins

6. Conclusions

1. Sluice gates composed of FRC and double-layered wire meshes are proposed. After sluice gates were installed, they weathered several hydrologic events. Despite this, monthly observations discovered that the gates had no noticeable cracks or rust stains, functioned normally, and maintained their watertight seals. Thus, the sluice gates were operational considering their size and weight specifications.

2. During the construction of the FRC sluice gates, the percentage of coarse aggregate per unit volume of concrete (m3 /m3 ) should be set to be at least 35%, with a Los Angeles abrasion loss of <40%.

3. After one year of use, both the Houanliao and Tanduliao sluice gates were removed from their respective embankments and returned to our laboratory for comprehensive inspection. The Houanliao sluice gates had barnacles and oyster shells attached at the bottom but exhibited no noticeable deformation, wear, or cracks. Both sluice gates were concluded to have been highly resistant to the impact of water flow.

4. The results of corrosion current and potential on the rebars and wire meshes of both sluice gates indicated no corrosion. Thus, these sluice gates, which had a 20-mm-thick protective cover and comprised FRC, afforded adequate protection for the rebars within.

5. No matter in Tanduliao or Houanliao, the difference between the compressive strength, splitting tensile strength, elastic modulus and chloride diffusion coefficient before field testing and after one year exposed is within ±6%.

6. The fiber-reinforced concrete sluice gates were one-tenth the cost of the stainless steel sluice gates and one-fifth the cost of cast iron ones. FRC sluice gates are less likely to be stolen because of their zero salvage value. In addition, they can be employed in low-head areas and drainage basins.