For a new type of postearthquake temporary prefabricated lightweight steel structure proposed in this paper, mainly composed of steel frame, prefabricated hanger slabs, prefabricated hanger columns, reinforced concrete superposed slabs, etc., parameters of dynamic property for the structure, including natural frequency, vibration mode, damping ratio, etc., are determined by the test method. For prefabricated hanger columns and prefabricated hanger slabs, they are all produced with construction waste in factory and assembled on-site, which can form exterior walls. The united method, based on forced vibration method and ambient random vibration method, can quickly obtain accurate natural frequencies of the full-scale two-story experimental model. In this paper, damping oscillatory method is used to obtain damping ratio which can be determined only by the test method. In order to analyse the modal of the experimental model, a finite element model for the full-scale two-story experimental model is established, where the weight of prefabricated hanger slabs is assumed to be supported by prefabricated hanger columns, and the stiffness of prefabricated hanger columns is also increased. In addition, the connections between lightweight steel frame and prefabricated hanger columns are regarded as flexible connection. Comparing natural frequencies obtained from the finite element method with that obtained from the test method, magnification factor of stiffness for prefabricated hanger column is determined. In the analysis of modal for the full-scale two-story experimental model, the results show that the experimental model satisfies the requirement of design for seismic performance.
The purpose of this research is to put forward a new energy-efficient building system that can meet the energy saving requirement of 65% for public buildings in cold areas based on modified insulated concrete perforated brick with a sandwich. Modified brick was composed of three parts and three parts can be made a whole in brick manufacturing and it was called self-thermal insulation concrete perforated brick and could avoid appearance of cracks. The tesst was done to obtain thickness of EPS for modified insulated concrete perforated brick with a sandwich in order to meet the requirement of insulation. Thickness of EPS was set to to 45, 50, 55, 60, 65 and 75 mm respectively and comparative experiments were also carried out to verify the effect of insulation for modified bricks and unmodified bricks. Field tests were carried out to obtain appropriate masonry methods for modified bricks. Based on the results of analysis and discussion, then obtained: (1) Heat transfer coefficient of wall made by modified bricks was less than heat transfer coefficient of wall made by unmodified bricks when the same for thickness of EPS, it could be reduce by up to 45%; (2) When thickness of insulating layer was 65 mm, heat transfer coefficient of wall made by modified bricks could reached minimum limit 0.45 and it could meet energy saving requirement of 65% for buildings in cold area. (3) Insulating layer, located inside of the wall, could avoid appearance of cracks on surface of wall for modified bricks.
For the postearthquake temporary prefabricated light-weight steel structure, the enclosure walls composed of prefabricated slender columns and prefabricated strip slabs were used in the structure, which were manufactured from construction waste, such as fragments of bricks and tiles, concrete fragments, and chippings of stones. In order to obtain more accurate seismic performance of enclosure walls, a full-scale two-story experimental model was built to be placed on a shake table. In the test, acceleration transducers were fixed to the enclosure walls and steel frame, which were used to obtain the maximum acceleration of the enclosure walls and steel frame as well as natural frequency of the experimental model subjected to the seismic signal including Kobe wave and El-Centro wave. Moreover, pull-on the rope displacement transducers fixed to the exterior walls parallel to the direction of vibration were used to obtain the story drifts. The results of the shake table test show that when the experimental model is subjected to earthquake with maximum acceleration, enclosure walls are not damaged, owing to flexible connection between the steel frame and enclosure walls. Earthquake reduces the stiffness of enclosure walls, and the natural frequency of the experimental model decreases with increasing maximum acceleration of the seismic signal. In addition, based on the acceleration amplification coefficient, the collaborative performance of the steel frame and enclosure wall is better. Besides, when the experimental model is subjected to earthquake with maximum acceleration, the maximum story drift angle is only 1/2615.
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