دانلود رایگان مقاله رفتار پی وی سی تقویت شده روکش دیوار بتنی تحت بارگذاری محوری خارج از مرکز

ABSTRACT

Recently, polyvinyl chloride (PVC) has been used as a stay-in-place (SIP) formwork because of its lower cost compared to other materials, durability, and ease to assemble. The PVC SIP formwork used here consists of interconnected elements; panels and connectors that serve as permanent formwork for the concrete walls. In this paper, the behaviour of the PVC encased reinforced concrete walls tested under eccentric compression loading was investigated. The variables were the type of the specimen (PVC encased or control), the longitudinal reinforcement ratio (0.65% or 1.3%) and the eccentricity of the applied load. The PVC encased wall specimens showed superior performance, more ductile and higher capacity when compared to the control wall specimens. An analytical model was developed to predict the ultimate load capacity of the specimens taking into consideration the effect of the PVC on the load carrying capacity of the walls. The calculated and experimental peak loads were in good agreement.

6. Conclusion

The following conclusions can be drawn from the work presented here: 1. The PVC encased specimens showed a higher peak load than their peer control walls. The effect of the PVC encasement on increasing the ultimate capacity at a given eccentricity was more significant for the walls reinforced with 4-10 M than the walls reinforced with 4–15 M. For a given reinforcement ratio, the PVC effect on the concrete encasement was more pronounces as the eccentricity increased. 2. The control walls failed by yielding of the steel followed by crushing of the concrete, or by crushing of the concrete without yielding of the steel. For the PVC encased walls, buckling of the PVC occurred after the concrete crushed. 3. The control walls and their peer PVC encased walls showed the same mode of failure except for the control and the PVC encased walls reinforced with 4–10 M and tested at 67.7 mm eccentricity. This is due to shifting the mode of failure from tension failure (steel yielding then concrete crushing) for the control walls to close to the balanced failure (steel yielding and concrete crushing) for the PVC encased walls. 4. Both the control and PVC encased specimens showed the same load versus deflection behaviour. The PVC encased specimens were stiffer than the control specimens, where the slope of the load versus de- flection increased for the vertical and the mid-span deflection, the PVC encased specimens and the control specimens showed the same values at failure but the PVC encased walls failed at a higher load. 5. Sectional analysis based on the moment magnification factor was carried out to calculate the capacity of the walls. The calculated capacities showed better correlation with the experimental peak loads when the confining effect of the PVC was taken into consideration than the case with zero confinement.