Test And Performance Study Of Structural Thermal Insulation Expanded Perlite Concrete

With the vigorous development of China's construction industry,the requirements for building energy conservation and environmental protection and thermal insulation performance of building materials are getting higher and higher.The use of a new type of building energy-saving concrete-structure thermal insulation expanded perlite concrete can improve the thermal insulation performance of the building envelope and meet China's requirements for building energy conservation.The design method,mechanical performance,thermal insulation performance,working performance,frost resistance and other aspects of structural thermal insulation expanded perlite concrete were tested and studied.The main work is as follows:(1)based on concrete performance analysis,design the structural thermal insulation expanded perlite concrete,and use physical methods to make the structural thermal insulation expanded perlite concrete meet the strength requirements and thermal insulation requirements: by encapsulating hydrophobic expanded perlite,add nano-materials and secondary mixing technology to improve the strength of structural thermal insulation expanded perlite concrete,and mix with fumed silica and hydrophobic expanded perlite aggregate to reduce its thermal conductivity.(2)Determining the composition material and mix ratio of tructure thermal insulation expanded perlite concrete.Using orthogonal test,taking compressive strength and thermal conductivity as indexes,through variance and range analysis,the main factors affecting the compressive strength of concrete are :the content of fumed silica>water cement ratio>content of expanded perlite aggregate>nano calcium carbonate content;The main factors affecting the thermal conductivity of expanded perlite concrete are: the content of fumed silica>nano calcium carbonate content>water cement ratio>content of expanded perlite aggregate.(3)The influence and reason of structural thermal insulation expanded perlite concrete with mix ratio are analyzed,the optimal mix ratio is determined :The content of fumed silica is 90%,water cement ratio0.33,the content of expanded perlite aggregate is 90%,The content of nano calcium carbonate is 0.5%,The content of basalt fiber is 4kg/m3.The test results show that the structural thermal insulation expanded perlite concrete working performance well,the compressive strength is7.88 Mpa,thermal conductivity is 0.1296W/(m·k),splitting tensile strength is0.74 MPa,tensile pressure ratio was 0.094.(4)The freezing-thawing cycle test was carried out on the structural thermal insulation expanded perlite concrete test block.The results show that as the number of freeze-thaw cycles increases,the compressive strength and quality of the concrete gradually decrease,and the newly prepared structural thermal insulation expanded perlite concrete can withstand ? 35 freeze-thaw cycles,and the concrete freeze-resistant number is determined as D35.The breakdown mechanism of freeze-thaw cycle of structural thermal insulation expanded perlite concrete is analyzed.In order to facilitate the research,several features of the structure thermal insulation expanded perlite concrete are studied which include the relationship between the loss rate of compressive strength and the number of freezing-thawingcycles,the relationship between the loss rate of mass and the number of freezing-thawing cycles with the relationship between the loss rate of compressive strength and the loss rate of mass.(5)The thermal insulation performance of structural thermal insulation expanded perlite concrete is simulated.It is found that the wall thickness of 270 mm made of structural thermal insulation expanded perlite concrete can meet the requirements of energy saving standards,It is better than the thickness of traditional building outer wall(240mm)plus external insulation polystyrene board(100mm),in addition,the construction procedure of external thermal insulation for external wall is cancelled,saving cost and shortening construction period.The analyzes the economic benefit of structure thermal insulation expanded perlite concrete in order to reduce the cost.