Experimental Study On Fire Resistance Of Cross-Laminated Bamboo Board

The construction of new urbanization is an important task in China at present.The adoption of green ecological bamboo and wood structure system of new urbanization is an important direction of green building and building industrialization in China.China is abundant in bamboo resources which has the characteristics of short growth cycle,low energy consumption and low pollution in the process of production and utilization.In recent years,building fires in China have been on the rise.Bamboo and wood materials are facing serious fire protection problems.But carelessness may cause a large number of property losses and casualties.At present,there are few studies on fire resistance of crosslaminated bamboo(CLB).Therefore,the following work is carried out in this thesis:(1)Nine CLB boards were tested under ISO-834 standard heating curve in three groups: ordinary untreated,painted with fire retardant coating and impregnated with MAP.Each group of three CLB boards was subjected to fire for 45 minutes,60 minutes and 75 minutes,respectively.The results showed that the fire resistance of the painted group was the best.Ant the carbonization was the shallowest from the visual sense.The temperature in the component rose slowly and the temperature was lower.The fire resistance of impregnated with MAP group came the second.(2)In order to study the residual bearing capacity of CLB after fire,the ultimate bearing capacity of the nine boards above and one non-fire CLB board was tested.The results show that the longer the fire time of CLB board is,the smaller the residual bearing capacity is.The lowest reduction of the bearing capacity of the painted group is under the same fire time,followed by the ordinary untreated group.The residual bearing capacity of impregnated flame retardant group was the lowest due to chemistry.(3)Measuring the carbonization depth and calculating the corresponding carbonization speed of each CLB board after fire,the results show that the average carbonization speed of the ordinary untreated CLB plate after fire for 45 min,60min and 75 min is 0.56mm/min,0.8mm/min and 0.77mm/min,respectively.The carbonization speed of the corresponding components in the impregnated flame retardant group decreases slightly,while the carbonization speed of the coated fire retardant group decreases the most.And the fire retardant effect is the best.Based on formulas for calculating the carbonization depth of CLT in foreign codes,formulas for carbonization depth of untreated CLB boards was modified,which could provide reference for future engineering applications.(4)Finite element simulation of temperature field of ordinary untreated CLB boards under fire was established.Model change was used to consider the shedding of CLB board.The results show that the finite element model can accurately simulate the temperature field distribution and carbonization depth of CLB board under different fire time.