PDF(Pubmed)
Abstract：
Escalating global surface temperatures are highlighting the urgent need for energy-saving solutions. Phase-change materials (PCMs) have emerged as a promising avenue for enhancing thermal comfort in the construction sector. This study assessed the impact of incorporating PCMs ranging from 1% to 10% by mass into composite Portland cement partially replaced by fly ash (FA) and nanosilica particles (NS). Mechanical and electrochemical techniques were utilized to evaluate composite cements. The results indicate that the presence of PCMs delayed cement hydration, acting as a filler without chemically interacting within the composite. The combination of FA and PCMs reduced compressive strength at early ages, while thermal conductivity decreased after 90 days due to the melting point and the latent heat of PCMs. Samples with FA and NS showed a significant reduction in the CO2 penetration, attributed to their pozzolanic and microfiller effects, as well as reduced water absorption due to the non-absorptive nature of PCMs. Nitrogen physisorption confirmed structural changes in the cement matrix. Additionally, electrical resistivity and thermal behavior assessments revealed that PCM-containing samples could reduce temperatures by an average of 4 °C. This suggested that PCMs could be a viable alternative for materials with thermal insulation capacity, thereby contributing to energy efficiency in the construction sector.
摘要：
全球地表温度不断上升凸显了对节能解决方案的迫切需求。相变材料（PCM）已成为提高建筑行业热舒适度的有希望的途径。这项研究评估了将按质量计1％至10％的PCM掺入到部分被粉煤灰（FA）和纳米二氧化硅颗粒（NS）替代的复合波特兰水泥中的影响。机械和电化学技术用于评估复合水泥。结果表明，PCMs的存在延缓了水泥水化，作为填料，在复合材料内没有化学相互作用。FA和PCM的组合降低了早期的抗压强度，而导热系数在90天后由于PCMs的熔点和潜热而降低。具有FA和NS的样品显示出CO2渗透的显着降低，归因于它们的火山灰和微填料效应，以及由于PCM的非吸收性质而降低的吸水率。氮物理吸附证实了水泥基质的结构变化。此外,电阻率和热行为评估表明，含PCM的样品可以将温度平均降低4°C。这表明PCM可以成为具有隔热能力的材料的可行替代方案，从而有助于建筑行业的能源效率。
