近年來，氣候變遷、能源需求增加與天然資源消耗已成為全球重要議題。建築與營建產業涉及材料生產、施工、運輸及建築使用階段能源消耗，因此在淨零碳排與資源循環發展中扮演重要角色。營建廢棄物中含有大量磚瓦、混凝土及砂漿等無機材料，若未妥善處理，容易造成堆置、掩埋及環境負擔。若能將此類材料再製為具輕質與隔熱功能之水泥基材料，將有助於提升資源再利用效益，並增加建築節能之應用潛力。 本研究以再生磚砂（Recycled Brick Aggregate， RBA）與發泡聚苯乙烯（Expanded Polystyrene， EPS）為主要材料，探討其應用於隔熱砂漿及輕隔間灌漿材料之可行性，並評估低碳膠結材料導入後對工程性質與減碳效益之影響。研究分為四階段，第一階段探討再生磚砂取代機制砂對水泥砂漿工程性質之影響；第二階段導入EPS，分析複合材料之輕質化、隔熱、力學性能與均勻性；第三階段使用卜特蘭石灰石水泥（Portland Limestone Cement， IL）及爐灰水泥（BF）取代I型卜特蘭水泥（Portland Cement Type I， PC），其中BF由I型卜特蘭水泥、飛灰及爐石粉組成；第四階段則以生命週期評估概念，分析再生材料及低碳膠結材料之材料端減碳效益。 材料基本性質結果顯示，再生磚砂之粒徑分布與機制砂相近，但容積比重較低、吸水率較高，且小於75 μm材料含量較高，顯示其具有多孔、高吸水率及較易產生細粉之特徵。雖然物理性質與機制砂不同，但仍符合相關規範要求，具有作為水泥砂漿細粒料之應用潛力。 再生磚砂取代機制砂後，可降低砂漿密度與熱傳導係數，對材料輕質化與隔熱性能具有正面效果，主要與其低密度及多孔隙特性有關，孔隙可增加材料內部熱阻，阻礙熱量傳遞。然而，再生磚砂取代率提高後，砂漿吸水率增加，力學性能亦下降，因此應用時仍須兼顧隔熱效果與強度表現。 在再生磚砂與EPS複合材料試驗中，EPS體積取代率為影響材料輕質化、強度及隔熱性能之主要因素，EPS添加可進一步降低材料密度與熱傳導係數，但取代率過高時，砂漿基質不足，容易造成EPS包覆不完全、工作性不佳及局部分布不均。為評估EPS分布情形，本研究透過試體剖面觀察、容積比重分析及ImageJ影像分析，建立EPS分布均勻性之量化評估方法。結果顯示，水膠比、EPS用量、外加劑添加量及砂漿基質黏滯度皆會影響複合材料之均勻性。 綜合流動性、密度、力學性能、吸水率、熱傳導係數及均勻性結果後，本研究選定M30W60B100作為後續低碳膠結材料試驗之基準配比，其EPS體積取代率為30 %、水膠比為0.60、再生磚砂取代率為100 %。雖然該配比並非所有單項試驗皆為最佳，但在工程性能、隔熱性能與材料穩定性之間具有較佳平衡。 低碳膠結材料試驗結果顯示，導入IL水泥及BF後，複合材料之早期力學性能及吸水表現皆可改善，材料基質填充性與緻密性提高後，熱傳導係數亦略為增加。均勻性分析顯示，IL配比之EPS分布較穩定，且在工程性質、吸水率及均勻性方面具有較佳綜合表現，因此選作後續減碳效益評估之低碳配比。 減碳效益評估以B階段M30W60B0作為控制組，並以C階段IL配比作為低碳配比。材料端碳排計算結果顯示，IL配比較控制組可降低約20 %之材料端碳排放量；若以10 cm厚灌漿牆換算為單位面積碳排，亦呈現相同減碳趨勢。減碳來源主要來自PC水泥改為石灰石水泥後降低膠結材料碳排，其次為再生磚砂取代機制砂後減少新產製細粒料使用。 本研究顯示，再生磚砂雖具有較高吸水率與較低顆粒強度，但仍可作為水泥基材料之再生細粒料，其低密度與多孔特性有助於降低熱傳導係數。EPS導入後可進一步降低材料密度並提升隔熱效果，但會伴隨強度下降及分布均勻性問題。透過水膠比、EPS用量及外加劑添加量之調整，可改善複合材料工作性與內部分布，使其具備應用於隔熱砂漿及輕隔間灌漿材料之潛力。導入IL水泥後，材料仍可維持良好工程性質並降低材料端碳排放量，顯示再生磚砂、EPS與低碳膠結材料之組合，具有發展為低碳輕質隔熱型水泥基材料之可行性。;In recent years， climate change， increasing energy demand， and natural resource consumption have become major global issues. The building and construction industry involves material production， construction， transportation， and energy consumption during building operation， and therefore plays an important role in net-zero carbon reduction and resource circulation. Construction waste contains large amounts of inorganic materials， such as bricks， concrete， and mortar. If not properly treated， these materials may cause stockpiling， landfill pressure， and environmental burdens. Recycling them into lightweight and thermal-insulating cement-based materials may improve resource reuse and support building energy conservation. This study used recycled brick aggregate (RBA) and expanded polystyrene (EPS) as the main materials to evaluate their feasibility for thermal insulation mortar and grouting materials for lightweight partition walls. The effects of low-carbon cementitious materials on engineering properties and carbon reduction benefits were also investigated. The study was divided into four stages. The first stage investigated the effects of replacing manufactured sand with RBA on cement mortar properties. The second stage introduced EPS and evaluated the lightweight performance， thermal insulation， mechanical properties， and uniformity of RBA–EPS composites. The third stage used Portland limestone cement (Type IL， IL) and BF cement to replace Portland Cement Type I (PC). BF cement consisted of Portland Cement Type I， fly ash， and ground granulated blast-furnace slag. The fourth stage adopted the concept of life cycle assessment to analyze the material-related carbon reduction benefits of recycled materials and low-carbon cementitious materials. The basic material properties showed that the particle size distribution of RBA was similar to that of manufactured sand. However， RBA had a lower bulk specific gravity， higher water absorption， and a higher content of particles finer than 75 μm. These results indicated that RBA is porous， highly absorbent， and more likely to contain fine particles. Although its physical properties differed from those of manufactured sand， RBA still met the relevant specification requirements， showing potential as recycled fine aggregate in cement mortar. The RBA replacement tests showed that replacing manufactured sand with RBA reduced mortar density and thermal conductivity， improving lightweight and thermal insulation performance. This behavior was mainly related to the low density and porous structure of RBA， as its pores increased internal thermal resistance and hindered heat transfer. However， increasing the RBA replacement ratio increased water absorption and reduced mechanical properties. Therefore， thermal insulation performance and strength should both be considered when using RBA in cement-based materials. In the RBA–EPS composite tests， the EPS volume replacement ratio was the main factor affecting lightweight performance， strength， and thermal insulation. EPS further reduced material density and thermal conductivity. However， excessive replacement resulted in insufficient mortar matrix， leading to incomplete EPS coating， poor workability， and local nonuniformity. To evaluate EPS distribution， a quantitative uniformity assessment method was established using specimen cross-section observation， bulk density analysis， and ImageJ image analysis. The results showed that the water-to-binder ratio， EPS content， admixture dosage， and mortar matrix viscosity all affected composite uniformity. Based on flowability， density， mechanical properties， water absorption， thermal conductivity， and uniformity， M30W60B100 was selected as the reference mixture for the subsequent low-carbon cementitious material tests. This mixture had an EPS volume replacement ratio of 30 %， a water-to-binder ratio of 0.60， and an RBA replacement ratio of 100 %. Although it was not optimal in every individual test， it provided a better balance among engineering performance， thermal insulation， and material stability. The low-carbon cementitious material tests showed that IL and BF cement improved early-age mechanical properties and water absorption performance. As the filling effect and compactness of the mortar matrix increased， thermal conductivity also increased slightly. Uniformity analysis showed that EPS distribution in the IL mixture was more stable， and the IL mixture exhibited better overall performance in engineering properties， water absorption， and uniformity. It was therefore selected for the subsequent carbon reduction assessment. The carbon reduction assessment used M30W60B0 from Stage B as the control mixture and the IL mixture from Stage C as the low-carbon mixture. The results showed that the IL mixture reduced material-related carbon emissions by approximately 20 % compared with the control mixture. When converted to carbon emissions per unit area of a 10 cm thick grouting wall， the same reduction trend was observed. The main reduction came from replacing PC cement with limestone cement， followed by replacing manufactured sand with RBA， thereby reducing the use of newly produced fine aggregate. The results showed that although RBA has higher water absorption and lower particle strength， it can still be used as recycled fine aggregate in cement-based materials. Its low density and porous structure help reduce thermal conductivity. EPS can further reduce density and improve thermal insulation， but may also cause strength reduction and uniformity issues. By adjusting the water-to-binder ratio， EPS content， and admixture dosage， the workability and internal distribution of the composite can be improved， giving it potential for thermal insulation mortar and lightweight partition wall grouting materials. With IL cement， the material maintained good engineering properties while reducing material-related carbon emissions. These results demonstrate the feasibility of combining RBA， EPS， and low-carbon cementitious materials to develop low-carbon， lightweight， thermal-insulating cement-based materials.
