Study On Properties Of New Concrete Materials For Construction

Phase change materials have greater heat storage capacity.Combining phase change materials with concrete as building materials can improve the heat storage capacity of ordinary concrete materials,and has become a research hotspot in the direction of building energy conservation in recent years.However,conventional phase change materials have the problem of too low thermal conductivity.Adding them to concrete will seriously affect their storage / heat release efficiency.By adding an appropriate amount of materials with high thermal conductivity,the thermal conductivity of the phase change material can be increased to a certain extent.In the study,through the previous experimental research,it is proposed to add the treated waste dry battery carbon rod powder and a new type of porous aggregate foam metal copper to the concrete material to prepare a composite material.Study and test to get the design of the best ratio scheme of energy saving effect.First,the 20 # paraffin is used as a phase change material to study the optimal adsorption capacity of organic paraffin by porous media energy storage aggregate.Four kinds of porous framework materials,expanded perlite,shale ceramsite,expanded graphite,and copper foam metal,were selected to study the influence of adsorption time,preparation methods,particle sizes,and material types on the adsorption capacity of phase change materials.Based on comprehensive analysis,the optimal adsorption schemes were selected by selecting expanded perlite with a particle size of 2mm ～ 4mm,vacuum adsorption for 8 hours,and metal foam copper for 1 hour.In addition,the effects of mass ratio and particle size of carbon-doped carbon rod powder on the thermal conductivity of paraffin were studied.Through experimental analysis,it can be found that the amount of carbon rod powder has a positive correlation with the thermal conductivity of the phase change material,and the effect of improving the thermal conductivity of the phase change material is relatively obvious for the carbon rod powder with a smaller particle size.Secondly,2mm ～ 4mm expanded perlite was selected as the phase change energy storage aggregate,and the phase change concrete mortar was prepared by replacing the river sand with the same quality.Moreover carbon rod powders with different mass fractions were added to study the expanded perlite energy storage to research the influence of aggregate and carbon rod powder on the thermodynamic properties and phase change cycle performance of phase change concrete.By studying the thermodynamic properties of expanded perlite-carbon rod powder phase-change energy storage concrete,the mechanical strength of phase-change concrete will be weakened to some extent with the increase of the content of expanded perlite energy storage aggregate and carbon rod powder.The specific performance is that when the content of the phase-change energy storage aggregate is 25% and the content of the carbon rod powder is 30%,the compressive performance and splitting tensile performance of the concrete decrease to a maximum of 41.27%,46.48%,of which the effect of energy storage aggregate content is greater than that of carbon rod powder;in addition,with the increase of phase change energy storage aggregate content,the thermal conductivity of concrete will decrease accordingly,and the thermal insulation performance will increase.The maximum temperature of changeable concrete is 6 ℃ ～ 10 ℃ lower than that of ordinary concrete;with the increase of the content of carbon rod powder,it will enhance the storage / exothermic efficiency of phase change materials and accelerate the phase change process of phase change materials.By studying the cycle performance of the expanded and expanded perlite-carbon rod powder phase-change energy storage concrete: with the increase of the number of phase-change cycles,the thermodynamic properties of the phase-change material will all decrease to varying degrees,and the mechanical properties will be affected by the phase-change cycle.The impact is small,the decrease is within 10%,the decrease in thermal conductivity is the most obvious,the maximum is 16.33%,and the overall thermodynamic performance is less affected by the number of phase transition cycles.Through comprehensive analysis,it is determined that the expansive perlite phase-change energy storage concrete,the optimal content of expanded perlite energy storage aggregate is 20%,and the optimal content of carbon rod powder is 20%.Finally,a comprehensive study of the effect of phase change concrete walls on the dynamic thermal performance of the indoor environment.The test results show that: the expanded perlite-carbon rod powder phase change concrete wall prepared by the direct mixing method can effectively delay the indoor temperature change,carbon The addition of rod powder can accelerate the storage/exothermic efficiency of phase change materials;the interlayer method is used to prepare foam metal copper phase change concrete box models with different thicknesses(4mm,6mm,8mm,10mm).The increase of the thickness of the material,the better the overall dynamic thermal performance inside the box,but the addition of too much foam metal copper phase change energy storage aggregate will seriously affect the mechanical properties of the concrete.Comprehensive analysis,6mm thick foam The amount of metal copper energy storage aggregate is the best.