全再生骨料混凝土导热性能试验研究

Experimental study of thermal conductivity of recycled concrete

采用德国HFM436/3/1E导热仪测试再生混凝土导热系数,研究再生细骨料取代率、再生细骨料粉体含量对再生混凝土导热性能的影响规律,并与普通混凝土进行对比.研究结果表明,再生粗、细骨料可明显降低混凝土导热系数,再生粗骨料取代率为100%时,其导热系数比普通混凝土降低了12.2%;再生粗骨料取代率为100%不变,其导热系数随着再生细骨料取代率的提高进一步降低,100%再生粗、细骨料的全再生混凝土,其导热系数比普通混凝土减小了23.6%;再生细骨料中粉体含量在7%以内对再生混凝土导热性能影响很小.最后进一步研究玻化微珠(GHB)对再生混凝土导热性能的影响.

The influence of replacement ratio of recycled fine aggregate and content of recycled fine aggregate powder on the thermal conductivity of recycled concrete were investigated and compared to normal concrete by using the Germany＇s HFM436/3/1 E thermal conductivity meter. The results show that recycled aggregate can significantly reduce the thermal conductivity of concrete. Compared to normal concrete,the thermal conductivity reduced 12. 2% when the replacement ratio of recycled coarse aggregate（ RCA） is 100%. When keeping the replacement ratio of recycled coarse aggregate at100%,the thermal conductivity reduced with the increase of replacement ratio of recycled fine aggregate（ RFA）. The thermal conductivity reduced 23. 6% when the replacement ratio of coarse aggregate and fine aggregate were both at 100%. There is little influence on the thermal conductive performance of recycled concrete when the powder content of recycled fine aggregate within 7%. The influence of adding glazed hollow bead（ GHB） in recycled concrete was also studied.