碳捕捉对废弃混凝土复合相变储热材料性能的影响

Effect of carbon sequestration on the performance of waste concrete shape-stable phase change composites

为充分资源化利用废弃混凝土,捕捉和储存CO_(2),本工作利用废弃混凝土进行碳捕捉,分别采用经固碳和未固碳废弃混凝土为骨架材料,硝酸钠为相变材料,制备出了7种不同质量配比的复合相变储热材料。研究结果表明,废弃混凝土在最佳实验工况下固碳效率高达24.7%;在添加相同质量分数的相变材料情况下,固碳复合相变储热材料的熔化潜热高于未固碳复合相变储热材料;样品SS2的抗压强度高达121.54 MPa,固碳废弃混凝土及其复合相变储热材料的抗压强度均有较大提升,最高热导率[0.648 W/(m·K)]低于未固碳样品[0.884 W/(m·K)];固碳前后的废弃混凝土骨架材料均与相变材料颗粒结合致密,材料各组分间的化学相容性较好。

In order to fully resource the use of waste concrete to capture and store CO_(2),this paper utilizes waste concrete for carbon capture,and seven composite phase change heat storage materials with different mass ratios were prepared by using carbon consolidated and unconsolidated waste.Results indicate that the carbon sequestration efficiency of the waste concrete was as high as 24.7% under the specific experimental conditions.The latent heat of melting of the shape-stable phase change composites prepared by carbon sequestration was higher than that before carbon sequestration after adding the same mass fraction of phase change material.The compressive strength of SS2 was as high as 121.54 MPa,and the compressive strengths of both the carbon sequestered waste concrete and shape-stable phase change composites were significantly increased,with the highest thermal conductivity [0.648 W/(m·K)] being lower than that of the un-sequestered sample [0.884 W/(m·K)].The shape-stable phase change composites before and after carbon sequestration had good chemical compatibility among the components,and the phase change materials were densely bonded with the skeleton materials.