Study On Fire Resistance Behaviors Of Thermal Insulation Masonry Sandwich Walls

With the continuous development of economy and the continuous improvement of urbanization rate,the total energy consumption of the whole society is increasing rapidly,and the negative impact of energy consumption on the environment and the sustainable development of the economy are becoming increasingly prominent.In the energy consumption of the whole society,building energy consumption has been occupies a considerable proportion,building energy conservation has become the nation's basic national policy,EPS external thermal insulation technology is widely used as a significant energy saving effect.At the same time,due to the wall with EPS thermal insulation material,fire safety problems of external thermal insulation technology has attracted extensive attention of the whole society.With the continuous improvement of energy conservation standards,the use of EPS insulation materials will further increase,and the harm brought by fire hazards will be further expanded,especially in the cold areas where the fire hazards and the risk of falling off are more obvious.Therefore,it is of great social significance and engineering value to realize that EPS insulation material can eliminate fire hazards under sufficient protection by sandwich insulation technology.In this paper,the fire resistance performance of the sandwich insulation block wall is analyzed and studied.The specific work is as follows:1.This paper studies thermal performance of the wall with different types and thickness of thermal insulation material.The heat transfer coefficient of the wall is calculated according to the standard specification and finite element calculation,and the heat insulation performance of the sandwich insulation block wall is verified.The results show that sandwich insulation block wall with the 100 mm thick rock wool or EPS can meet the relevant requirements in cold regions,and the thickness of the insulation material in other regions can be adjusted appropriately.2.Carried out one-side fire test on 6 sandwich insulation block walls,we observed the phenomenon in the process of fire on the wall.According to the section temperature field distribution of the specimen,the influence of fire mode,insulation material type and thickness on the fire resistance of the wall was analyzed.The test results show that the block sandwich walls with rock wool and benzene board as insulation materials can meet the requirements of(GB/T 8878.1-2008)‘Fireresistance test:elements of building construction' on bearing capacity,integrity and heat insulation under the condition of exposure to fire for 60 minutes,the fire resistance limit of other walls is greater than 4 hours.3.Based on the heat transfer correlation theory,we usethe ABAQUS software to establish finite element model of the specimens.The thermal parameters of materials such as block and mortar at high temperature were studied and input them into the model.On this basis,the fire resistance limits of rock wool and EPS sandwich insulation block walls were simulated to be 2.6h and 2.1h respectively,the numerical simulation data can fit well with the experimental temperature field data,with a small error and within the acceptable range,which indicates that the finite element method is feasible.4.Finite element software abaqus was used to build the model,and the factors affecting the fire resistance of sandwich insulation block wall were studied.The influence of insulation material thickness,block hole ratio and fire mode on wall temperature field is analyzed.The results show: the fire resistance limit of sandwich insulation block wall has a parabolic relationship with the thickness of insulation layer.The change of the hole ratio of the outer sheet wall block has little influence on the fireproof performance of the wall,while the change of the hole ratio of the inner sheet wall block has great influence on the fireproof performance of the wall.By comparing the temperature field of the wall section under the condition of fire on one side of the outer page wall and the inner page wall as well as on both sides,the results show that the fire resistance performance of the wall section under the condition of fire on one side of the outer page wall is better than that of the inner page wall.Under the condition of fire on both sides,the wall heats up rapidly and the cross section temperature field tends to be horizontal.