Theory and influencing factors on high temperature spalling cracking of concrete were introduced. A simplified analysis method was proposed combining the research results of high temperature spalling and peeling of concrete at home and abroad. The secondary development based on CAD-VBA was used to generate the concrete meso-geometry model
and ADINA nonlinear analysis software was used to establish thermal coupling model. The bursting and spalling process of concrete structures under high temperature was simulated by the finite element model
and the main influencing factors on high temperature spalling and spalling of concrete were analyzed. The results show that: (1) The closer to the fire boundary
the higher the burst damage; (2) The high temperature burst generally occurs in the cement ingredient within the range of 0cm to 5cm to the boundary of the fire
and the concrete structure (two-dimensional) bursts and peels off. The proportion of the damage area to the total area of the structure is small; (3) With the increase of fire boundaries (faces)
the heating rate
the pore water vapor pressure
the concrete strength grade
the thermal expansion coefficient of the aggregate and the application of boundary load
the time required for bursting and spalling of structures reduces; (4) The number of fire boundaries (planes)
external loads of the structure field
and the strength grade of concrete have little effect on the damage degree due to burst spalling. The heating rate
pore water vapor pressure
and the thermal expansion coefficient of aggregates have great influence on the damage degree of burst spalling.
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references
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