Experimental and numerical simulation research on charring properties of engineered bamboo exposed to four-side fire
Existing studies on the charring properties of engineered bamboo generally suffer from deficiencies such as short duration of fire exposure and untimely extinguishing of fire.As an attempt to solve this problem,this study conducted comparative experimental tests on the charring properties of eight engineered bamboo columns exposed to four-side fire.The studied parameters included the material type,section size,fire direction,processing technology and fire exposure time.The results show that the section of engineered bamboo after charring can be basically divided into three areas,namely,charring layer,pyrolysis layer and normal temperature layer.The corner area of the engineered bamboo in the four-side fire changes from corner to arc due to heating from two directions.The charring rate of engineered bamboo decreases slightly with the increase of fire exposure time,and the charring rate of the specimen with larger section size is slightly lower.Under the same condition,the charring rate of bamboo scrimber is significantly lower than that of laminated bamboo.The charring rate of the transverse grain is slightly higher than that of the tangential grain,and the difference is not obvious when the fire time is longer.The charring performance of the bamboo scrimber compressed once is slightly better than that of the bamboo scrimber compressed twice.A numerical model was also proposed to predict for the charring properties of engineered bamboo.The numerical model can quickly simulate the charring performance of engineered bamboo,and the error of simulated charring rate is within 10.2％,which meets the engineering accuracy requirements.The proposed calculation model can accurately predict the charring depth of engineered bamboo.Based on the fire test and numerical simulation results,it is suggested that the nominal linear charring rate of laminated bamboo and bamboo scrimber for 1.00 h in fire design can be taken according to the standard T/CECS 1101-2022'Standard for design of engineered bamboo structures',namely 54 mm/h and 30 mm/h respectively for laminated bamboo and bamboo scrimber members.
engineered bamboolaminated bamboobamboo scrimberfour-side fire testnumerical simulationcharring rate
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