Preparation And Test Analysis Of Phase-changing Energy-storing Concrete Of Lauryl Alcohol-expanded Perlite

Phase-changing energy-storing concrete(PCESC)has the function of energy storage and heat storage.It can absorb and release the heat in the environment through phase change in the building envelope structure,thus it can maintain the relative stability of indoor temperature,improve the comfort of indoor environment and reduce building energy consumption.Lauryl alcohol is selected as phase change material(PCM)and expanded perlite as adsorption material.Atmospheric pressure immersion adsorption method and vacuum immersion adsorption method are selected as preparation methods of phase-changing energy-storing aggregates(PCESA).Different properties of lauryl alcohol and expanded perlite are adopted.PCESA with different adsorption rates were prepared according to the ratio of amount.The reasonable adsorption rate of lauryl alcohol was determined by leakage test and phase change cycle test.The PCESA is encapsulated by wet wrapped cement powder and encapsulated by calcium silicate shell.Fly-ash ceramsite and shale ceramsite are used to make lightweight aggregate concrete with different design strength as the reference concrete.The 5%,10%,15%,and 20%unpackaged and encapsulated PCESA are added to prepare PCESC.The concrete cube compressive strength and splitting tensile strength are tested to explore the aggregate content,aggregate seal.The effects of loading and lauryl alcohol phase state on the tensile and compressive properties of concrete were studied.The effects of aggregate content,aggregate packaging and lauryl alcohol phase state on the thermal conductivity of concrete were investigated by thermal conductivity test.Through the adsorption experiments of different adsorption modes,time and temperature,the reasonable adsorption time and temperature for immersion at atmospheric pressure are 4 h and 50? respectively;the reasonable adsorption time and temperature for vacuum immersion are 30 min and 50?C respectively.The reasonable adsorption rate of air immersion adsorption should be 45%.The FT-IR test showed that the whole adsorption process was a pure physical adsorption process.The wet-wrapped cement slurry and calcium silicate encapsulation were used to encapsulate PCESA.The PCESA without encapsulation and after encapsulation were tested by phase change cycling.It was found that the retention rates of the three groups of aggregates decreased with the increase of cycling times.The results of DSC and FT-IR measurement tests show that the thermal stability and chemical stability of the encapsulated PCESA are good.The results of compressive and splitting tensile tests of PCESC show that when the content of PCESA is not more than 20%,the amount of PCESA,whether the aggregates is encapsulated or not and the phase state of PCM in aggregates have no obvious influence on the compressive and splitting failure modes of concrete;the tensile and compressive strength of PCESC are all along with the content of PCESA.The compressive strength of fly ash ceramsite concrete with maximum reduction of 21.86%,and the splitting strength of fly ash ceramsite concrete with maximum reduction of 22.18%.The compressive strength and splitting strength of shale ceramsite concrete have maximum reduction of 26.17%and 28.27%respectively.The experimental results of the thermal conductivity of PCESC indicate that the thermal conductivity of PCESC decreases gradually with the increase of the content of PCESA,and the thermal conductivity of concrete decreases 19.60%.The thermal conductivity of liquid concrete is higher than that of solid concrete,and the encapsulated concrete is higher than that of unencapsulated concrete.The results of phase change cycling test of PCESC show that within 100 cycles,the compressive strength of each group with different cycles decreases with the increase of aggregate content.The change rule is same as the non-cycling PCESC.The compressive strength of phase change energy storage concrete is little affected by different cycles of phase change,and the compressive strength has little change.Figure 41 table 25 references 84...