Research Of Construction And Fire-resistant Performance Of Precast Concrete Composit Slab

The one-way non-prestressed composite slab with multiple ribs is one of new-style common concrete slab. Because of its special advantages in mechanical behavior of structure and potential economic benefits, most projects can be used in. To deal with the loss of economy, natural resources and casualties caused by increasingly common fire disaster, and little study on it, it’s necessary to study fire-resistant behavior of one-way non-prestressed composite slab with multiple ribs. For highlighting its good performance of fire resistance, comparative research is made with PK pre-stressed composite slab, which draws fire-resistant laws of each composite slab.In view of this, static structural analysis, thermal analysis and thermal-structural coupling analysis is performed in this paper, and the influence of various factors on structural performance is taken into consideration, which offers the theoretical foundation for structural design and fire-resistant design. Main contents are listed as follows:1. Research achievement and research progress of the existing system of composite slab are generalized. Two types of one-way non-prestressed composite slab with multiple ribs, deck type and through type, is presented based on difference of construction. Superiority of one-way non-prestressed composite slab with multiple ribs in aspect of structural performance and fire-resistant compared with that of existing composite slabs is discussed in this paper.2. Research achievement from abroad on temperature-time curve, the thermal performance parameters and mechanical performance parameters of concrete and reinforcement is generalized and summarized, which would provide theoretical support for the following analysis of finite element model on structural static mechanics, thermotics and thermal-structure coupling, and would provide theoretical foundation for study of mechanical performance and fire-resistant performance.3. Two types of one-way non-prestressed composite slab with multiple ribs different from construction is introduce in detail. Structure performance and fire-resistant performance of each type of composite slab is articulated, and merit and demerit is generalized by contrast.4. The finite element models on analysis of static structural of one-way non-prestressed composite slab with multiple ribs, deck type and through type, in construction stage and normal service stage are established by ANSYS, finite element software. To research the influence of their static performance, numerical value of different influences is changed. The calculation model is simplified. The structural size is optimized based on results of FEM calculation, Finally, the range of application of the slab is presented.5. The finite element models on analysis of sectional temperature distribution of one-way non-prestressed composite slab with multiple ribs, deck type and through type, and PK pre-stressed composite slab are established by ANSYS, finite element software, which finite element result of shows the distribution regularity of temperature along highness of slab section. Thickness of concrete protective cover on reinforcement temperature-rise curve is main influence factor by comparative research. In addition, the failure mode of each composite slab is preliminarily judged combined with stress nephogram of reinforcement and concret at time of analysis of static structural, and duration of fire-resistant is estimated on the whole combined with material stress-strain relationship,6.The finite element models on analysis of thermal-structure coupling of one-way non-prestressed composite slab with multiple ribs, deck type and through type, and PK pre-stressed composite slab are established by ansys finite element software, which visually shows the durations of fire resistant of two-type slab by comparative research of change of bearing capacity and rigidity and feature of failure mode, and the main influences of duration of fire-resistant are made clear. Finally, some measures are put forward for improving fire-resistant performance and increasing duration of fire-resistant.