Ming Zhou

Experimental Study of Post-Fire Performance of Ceramsite Concrete Filled Steel Tabular Columns

The post-fire performance of a set of ceramsite concrete filled steel tabular short columns (noted as CCSSC) after exposure to fire are experimentally studied. Effect of the maximum value of fire response temperatures and geometrical parameters of the composite columns on the strength and ductility of the specimens were especially discussed. The test results show that the specimens of CCSSC have higher post-fire bearing capacity and better ductility, and both of maximum response temperature and geometrical parameters of the specimens presented here have great effect on the post-fire bearing capacity and ductility of ceramsite concrete-filled steel short columns after exposure to fire.

Numerical Analysis of Fire Behavior of a Large Space Pre-Stressed Steel Structure under Fire

The computational model of numerical analysis of a suspended pre-stressed steel reticulated shell subjected to fire load is established with using the software Marc. Based on the model presented here, numerical analysis of thermal response and structural response of the pre-stressed steel structure are computed. The different space height and different rise-span ratio are considered for analysis of response temperature, displacements and stresses of the pre-stressed lattice shell under fire for one fire source. It is also shown that displacement of the node right above the inner cable is the maximum among the four nodes presented here as the fire source is located at the position right below the second-ring cable of the structure. It is concluded that the influence degree of space height of the structure on the fire response of the structure is not great, but rise-span ratio has obvious and great effect on displacements and stresses of the pre-stressed steel structure with large span in fire.

Analysis of Fire Response of a Spacial Pre-Stressed Steel Structure Subjected to Fire Load

The numerical model for analysis of fire behavior of the spatial pre-stressed steel structure is established based on the software Marc. Analysis of thermal response and structural response of a suspended pre-stressed steel reticulated lattice shell are computed for the key nodes of the structure. For comparison, the air temperatures near the key nodes are also calculated based on the practical formula of large space air temperature rise. The different location of fire source is considered for analysis of response temperature, displacements and stresses of the nodes of the pre-stressed lattice shell. It is shown that the air temperatures obtained from the practical formula was always higher than the response temperatures of the nodes of the lattice shell during a quite long time after a fire takes place. The results show that the displacement of the node near the center of the gymnasium in fire is close to that of the node right above the inner cable, and the displacement of the node right above the outer cable is much less than the result of the center node.

Orthogonal Test of Characteristics of Complex Cememting Material of FGD Gypsum-Fly Ash

Orthogonal test method is used to study the effect of the mineral admixtures on the performance of FGD gypsum-fly ash complex cementing material. On the basic experiment, the effect of the traditional alkali and salt admixtures added to the complex cementitious system is discussed, the factors effecting on performance of the FGD gypsum were analyzed. Based on the experimental results, the best mix proportion was determined. Finally, the basic performance of complex cementitious material was tested. The experimental results show that the performance of FGD gypsum which is activated through adding the compound admixtures was similar with the ordinary interior wall materials. The strength and water resistance of FGD gypsum complex cementing material can be greatly enhanced by adding cement, quicklime and slag powder, and effect of cement is largest, and slag smallest. The performance of the gypsum complex cementing material also can be improved after incorporation of a few of chemical admixture on the basis of adding mineral activators.

Research on Behaviour of a Pre-Stressed Suspended Lattice Shells Subjected to Fire Load

Numerical analysis of thermal response and structural response of a suspended pre-stressed steel reticulated lattice shell are conducted for the key nodes of the structure of a gymnasium on software FDS. Two different location of fire source are considered for analysis of response displacements and stresses of the nodes of the pre-stressed lattice shell and three cables. It is shown that the response temperatures of three cables set in the structure have similar variation trend for the fire scene presented here and the fire temperature near inner cable is highest among the three cables. It is concluded that the shell element of center of the structure has largest response stress, and the element above the side cable has larger stress than the shell element above the middle cable when the fire source is located at center of the gymnasium. It is shown that decrease of the pre-stress of the outer cable far away from the fire source is smallest among the three cables set in the structure.

Experimental Study of Mechanical Behavior of Ceramsite Concrete Filled Steel Tubular Columns Subjected to Fire Load

Mechanical behavior of a set of ordinary concrete filled steel tubular short column (note as NCSSC) and ceramsite concrete filled steel tubular short column (note as CCSSC) subjected to fire load are experimentally investigated. Effect of the parameters, such as the maximum value of fire temperatures, fire duration on the strength and ductility of the two types of specimens were especially discussed. The test results show that both of the specimens of NCSSC and CCSSC have higher post-fire bearing capacity and better ductility, there was no descent segment in post-fire load-displacement curves of the most specimens subjected to fire load. It was concluded that the maximum response temperature of specimens and fire duration time has great effect on the axial bearing capacity of concrete-filled steel tubular short columns subjected to fire. The maximum longitudinal strain of specimens of CCSSC is less than the corresponding value of the longitudinal strain of NCSSC.

Research on Post-Fire Bearing Capacity of Ceramsite Concrete Filled Steel Tubular Short Columns

Mechanical behavior and bearing capacity of ceramsite concrete filled steel tubular short column (noted as CCSSC) subjected to fire load are experimentally investigated. Effect of the parameters, such as the maximum value of fire temperatures, fire duration on the strength and ductility of the two types of specimens were especially discussed. The experimental results show that all the specimens of CCSSC have higher post-fire bearing capacity and better ductility, and there was no descent segment in load-displacement curves of the most specimens after the fire load was subjected. It was concluded that the maximum response temperature of specimens and fire duration time has great effect on the axial bearing capacity of concrete-filled steel tubular short columns subjected to fire, and the concrete mix proportion has some effect on both of bearing capacity and ductility of CCSSC subjected to fire load.

Research on Fire Behavior of a Suspended Pre-Stressed Steel Reticulated Shell with Large Span

In order to study the fire-resistance behavior of the spatial pre-stressed steel structures with large span, the model of numerical analysis of a suspended pre-stressed steel reticulated shell subjected to fire load is established with using the software Marc. Based on the model presented here, numerical analysis of thermal response and structural response of the pre-stressed steel structure are computed for the key nodes of the structure. For comparison, the air temperatures near the key nodes are also calculated based on the practical formula of large space air temperature rise. The different location of fire source is considered for analysis of response temperature, displacements and stresses of the nodes of the pre-stressed lattice shell. It is shown that the air temperatures was much higher than the response temperatures of the nodes of the lattice shell during a quite period of time after a fire takes place, and the temperature of the cable nodes are also less than the air temperature near the nodes. It is also concluded that not the cable nearest the fire source but the other cables around the cable fail to work first in the fire.

Study of Fire Behavior of a Profiled Sheet-Ceramsite Concrete Composite Floor

In order to study the fire behavior of the profiled sheet-ceramsite concrete composite floor subjected to fire load, research on fire response and post-fire bearing capacity of a profiled sheet-ceramsite concrete composite floor subjected to dead load, which has no shearing nails, is carried out here through experiment. Based on the experimental results, the fire behavior and post-fire bearing capacity of the floor after exposure to fire are analyzed. It is shown that the failure form of the profiled sheet-ceramsite concrete composite floor after exposure to fire has obvious change compared with the floor not subjected to fire load, but the composite floor subjected to fire still exhibits higher bending capacity, and the ultimate value of the equivalent distributed load is up to 35kN/m2, which may be used as basis of strengthening and repairing of the profiled sheet-ceramsite concrete composite floor after exposure to fire.

Test of Fire Response of a Profiled Sheet-Ceramsite Concrete Composite Floor

For study of the post-fire characteristics of the profiled sheet-ceramsite concrete composite floor (noted as PSCCF) subjected to fire load, the experimental research on post-fire bearing capacity of a PSCCF after fire is carried out. Based on the experimental results, effect of the fire on post-fire bearing capacity of the profiled sheet-ceramsite concrete composite floor is discussed, and the failure phenomenon and mechanism are analyzed. It is shown that the failure form of the profiled sheet-ceramsite concrete composite floor after fire has great change compared with the floor not subjected to fire load, but the composite floor subjected to fire still exhibits higher bending capacity, and the ultimate value of the equivalent distributed load is up to 25kN/m2, which may be used as basis of strengthening and repairing of the profiled sheet-ceramsite concrete composite floor after exposure to fire.