دانلود رایگان مقاله استفاده از فلکسی - دیوار در تجدید موانع سر و صدا

ABSTRACT

This paper presents an experimental study on structural performance of an innovative noise barrier consisting of poly-block, light polyurethane foam (LPF) and polyurea. This wall system (flexi-wall) is intended to be employed as a vertical extension to existing noise barriers (sound walls) in an accelerated construction method. To aid in the wall design, several mechanical tests were conducted on LPF specimens and two full-scale walls were then fabricated employing the same LPF material. The full-scale walls were subjected to lateral loading in order to establish their lateral resistance. A cyclic fatigue test was also performed on a full-scale flexi-wall in order to evaluate the performance of the wall under a repetitive loading condition. The results of the experiments indicated the suitability of flexi-wall in accelerated construction and confirmed that the structural performance of the wall system under lateral loading is satisfactory for the sound wall application. The experimental results were discussed and a preliminary design procedure for application of flexi-wall in sound wall applications was also developed.

5. Conclusions

This study investigates the first known application of light polyurethane foam (LPF) in construction of an extension to existing noise barriers. An experimental program was carried out to determine the LPF mechanical properties as well as the lateral resistance of the entire wall system. A fatigue test was also performed on a flexi-wall in order to evaluate its long-term performance under a repetitive loading. According to the results of this study, the following conclusions can be drawn: 1. The construction of a flexi-wall is significantly faster and more economic than the conventional method for the investigated application. The outcomes of the experiments showed that the structural performance of the wall for accelerated construction is completely acceptable. 2. Under a static loading, the flexi-wall exhibited a linear behavior up to yield point and its lateral resistance was satisfactory as a short extension to an existing noise barrier. 3. The results of cyclic loading tests confirmed the reliability of the flexi-wall behavior in the range of design loading. The cyclic loading yielded only 5.1% stiffness loss after 15,000 cycles which is quite comparable to fatigue characteristics of other types of material. 4. The mechanical performance of the flexi-wall is mainly governed by the steel rebars and as LPF is lighter and less expensive than cementitious material, a flexi-wall can be a good alternative to other types of extension for the investigated application. Even though not examined in the current study, it is expected that applying a layer of shotcrete on the wall surfaces could enhance the flexural resistance, surface resistance and fatigue characteristics of the wall.