Study On Reasonable Structure And Thermal Insulation Effect Of CL Type External Wall Non-disassembly Thermal Insulation Formwork

CL type exterior wall free dismantling thermal insulation formwork is a new type of external wall composite formwork with thermal insulation function and formwork function.It has the advantages of no demolition,good thermal insulation performance,easy construction and operation,high safety and the same life as the main structure of the building.However,if the structural form of the formwork or the selection of thermal insulation materials is improper,problems such as unsatisfactory thermal insulation effect,fire and leakage of buildings may occur.In order to study the reasonable structure of the CLtype exterior wall without dismantling the thermal insulation formwork and the thermal insulation effect under the action of long-term climatic environment,this paper mainly adopts the method of combining theoretical analysis,numerical simulation and laboratory test.Based on the thermal performance and thermal insulation requirements of the formwork,the thicknesses of three typical thermal insulation materials commonly used in Anhui Province are calculated.The reasonable structural form of the composite thermal insulation formwork without dismantling of the material;through the freeze-thaw resistance test,weather resistance test and numerical simulation,the thermal insulation effect of the formwork under the action of long-term climate is analyzed;The construction process of dismantling the thermal insulation formwork.The main conclusions are:First,based on the thermal insulation requirements of residential buildings in areas with hot summers and cold winters,the thicknesses of three typical thermal insulation materials,XPS board,EPS board and rock wool board,are calculated.The calculation results show that when the shape coefficient K of the building is less than 0.4,the thicknesses of XPS board,EPS board and rock wool board are 20.0mm,25.3mm and 26.7mm respectively;The thickness of the board and rock wool board are 30.0mm,38.0mm and 40.0mm respectively.Secondly,it is proposed that the fireproof structure of the thermal insulation formwork without dismantling is mainly considered from three aspects: fireproof protection layer,fireproof isolation belt and no cavity structure.When the combustion grade of the thermal insulation material is Class B,the thickness of the first layer of the fire protection layer should not be less than 15 mm,and the thickness of the remaining layers should not be less than 5mm.It should not be less than 300 mm.When there is no cavity structure,the walls on both sides of the insulation material should be made of non-combustible materials and the thickness should not be less than 50 mm.Thirdly,it is proposed that the waterproof structure of the dismantling-free thermal insulation formwork mainly considers the waterproofing of the formwork itself and the leakage prevention of the joints.Among them,self-waterproofing can use the combination of anti-crack mortar and waterproof mortar with additional alkali-resistant mesh cloth;the waterproofing of joints can use cavity structure and material sealing and waterproofing.The method of cavity structure is more complicated than that of material sealing and waterproofing,but the effect is better and the validity period is longer.Fourth,according to the fireproof structure requirements,waterproof structure requirements and thermal insulation requirements of the external wall free-dismantling thermal insulation formwork,a reasonable structural form of the CL type external wall freedismantling thermal insulation formwork is proposed.Its main constituent materials are:XPS extruded polystyrene board,anti-cracking mortar,alkali-resistant mesh cloth,cement polystyrene board particle mortar.Through factory prefabrication,all materials are integrated to form a composite material template with thermal insulation performance and certain bearing capacity.Fifth,the template is subjected to freeze-thaw resistance test and weather resistance test in turn to simulate the damage of the non-dismantling insulation template under long-term climatic conditions.The thermal conductivity of the XPS extruded polystyrene board before and after the test was measured using a double-plate thermal conductivity tester.The results show that the thermal conductivity of the XPS extruded polystyrene board after the test is about doubled compared with that before the test.Sixth,the thermal insulation effect of the template before and after the test was simulated by finite element software.The results show that the CL outer page board can have a good thermal insulation effect in winter and a good thermal insulation effect in summer,so as to reduce the energy consumption of the building;under long-term climatic conditions,the thermal insulation of the formwork The thermal insulation function will be significantly affected.Finally,the construction technology of the CL-type exterior wall without dismantling the thermal insulation formwork is proposed,including the preparation before construction,the main construction technology and the key construction technical points.