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Installing reinforcement piles is an effective method to mitigate ground movement in liquefied soils. In this study, the effectiveness of the pile-reinforcement method is evaluated using an advanced finite element program OpenSeesPL. Parametric studies are conducted to investigate key parameters in the mitigation model, including pile area replacement ratio, pile diameters and pile-embedment length. The effectiveness of pile reinforcement to reduce large flow deformation in the liquefied ground is significantly influenced by the pileembedment condition. It is recommended the embedment length is at least 1 m or 2 m if the underlying soil is a dense or a medium sand. [ABSTRACT FROM AUTHOR]

The bond behavior of reinforcing bars is an important issue in the design of reinforced concrete structures and the use of fiber reinforced polymer (FRP) rebars is a promising solution to handle the problems of steel reinforcement corrosion. This study investigates the bond characteristics of carbon and aramid FRP (CFRP and AFRP) bars embedded in normal strength concrete. A pullout test was performed on 63 normal strength concrete specimens reinforced with FRP and steel rebars with different embedment lengths and bar diameters. The average bond stress versus slip curve is plotted for all specimens and their failure modes are identified. The effects of the embedment length and diameter of an FRP rebar on its bond strength are examined in this work. The bond strengths obtained from the test results are compared with the predictions by the bond strength equation proposed by Okelo and Yuan (2005), and its validity is evaluated. [ABSTRACT FROM AUTHOR]

The recycling of industrial waste such as bottom ash from furnaces is an important issue in construction industry, since it enables reduction in construction cost and has beneficial effect on the environment. In this study, we have investigated the bond characteristics of steel deformed bars embedded in artificial lightweight aggregate concrete which is manufactured from bottom ash. A pullout test was performed on 144 light-weight aggregate concrete specimens to measure the bond strengths. In this test, the parameters included the compressive strength of the concrete and embedment length of rebar. The pullout load vs. slip responses and modes of failure of the specimens were identified during the test. A bond strength equation for lightweight concrete is formulated by performing a regression analysis on the test results and compared with the predictions by the existing equations such as ACI 408, Orangun's, and Darwin's. The comparison shows that the existing bond strength equations cannot be directly applied to the design of lightweight concrete structures and the proposed equation is able to provide a more accurate estimation of the bond strength of lightweight concrete than the existing equations. [ABSTRACT FROM AUTHOR]