磷硅水泥基全植物茎杆骨料混凝土设计原理及保温调湿调控机制

Using crop stalks to produce building materials can contribute to sustainability in construction. There are two current issues which prevent using crop stalks in concrete: First, the lack of compatibility between cementitious materials and crop stalks. Second, the produced cement has only single functionality. The purpose of this research proposal is to develop incorporation of phosphate-silica cement with crop stalks as a bio-based composites to construct a new type of building materials. The favorable characteristics of phosphate-silica cement including fast setting and neutral medium after hydration, along with the presence of microspores in crop stalks can lead to a new cement-based composite. This will set up a bridge to fill in the gap between the crop and modern construction. The desired composite offers low density with uniformly distributed crop stalks and holds the function of thermal insulation and humidity control. This research will focus on the physical characteristics of the stalks, their optimum content, and distribution inside the concrete, the constitutive behavior of the concrete binder, as well as the processing parameters technology. The objective of this study is to make a novel stalks concrete composite for economic construction design. To this end, the evolving mechanisms of thermal performance, mechanical properties and durability will be studied. Furthermore, to provide a theoretical understanding of the environmental effects on the potential structural change of the stalks concrete, mathematical and physical models will be developed. The expected results will include the optimal mechanism and regulation methods concerning the characteristics of the stalks concrete. Besides, the indoor and outdoor equilibrium equations for thermal and humidity properties will be established, aimed to assess theoretical function for the next generation of eco-efficient construction materials. The above research and results will be completely innovative.This study aims to set up a bridge to fill the gap between the crop and modern construction, to realize the reproducible construction materials. Further, it can become a theoretical foundation for the next generation of eco-efficient construction materials.

将可再生的农作物茎秆用于建筑材料的开发可实现建筑真正的可持续性。针对植物茎秆与现有胶凝材料存在的不相容和其产品功能单一化的技术瓶颈，本项目拟将具有快硬和硬化后呈中性的磷硅水泥与内部具有微孔结构的植物茎秆复合，实现茎秆与胶凝材料相容并制备出具有保温隔热调湿特性的功能性茎秆骨料混凝土。通过宏/微观结构测试与化学表征探明茎秆骨料物性参数、掺量、空间分布、胶凝材料组成及制备工艺等诸多因素对茎秆骨料混凝土综合性能的作用机制，实现茎秆骨料混凝土的组成与结构的可设计，研究茎秆骨料混凝土在服役过程中的热工性能、力学性能与耐久性的演化规律，提出其影响机制与调控方法。基于热传质理论，建立茎秆骨料混凝土围护结构传热传质数学物理模型及室内热湿平衡方程，为茎秆骨料混凝土围护结构进行整体环境改造提供理论依据。本研究旨在为农业与建筑业之间搭建一个桥梁，实现建筑材料可再生，为下一代绿色建筑材料奠定理论基础。

将可再生的农作物茎秆用于建筑材料的开发可实现建筑真正的可持续性。本项目针对植物茎秆与现有胶凝材料存在的不相容和其产品功能单一化的技术瓶颈，通过诱导、靶向激活原理将工业废渣大掺量取代氧化镁制备了低成本的磷酸镁水泥，并将其作为主要胶凝材料用于解决秸秆与胶凝材料之间相容性问题。通过对掺有不同工业废渣合成的磷硅水泥水化产物及微观结构分析，探明了基于大掺量工业废渣的磷酸镁水泥凝结硬化后物相组成及其与茎秆骨料嵌合界面微观结构，实现了磷酸镁水泥基植物秸秆混凝土良好的耐久性；在大量宏观性能测试数据基础上并结合微观结构观测，揭示了秸秆尺寸、掺量等参数对秸秆混凝土性能影响作用机制，给出了磷酸镁水泥基植物秸秆混凝土配比设计方法。所制备的秸秆混凝土干表观密度在500 kg/m3 - 1450kg/m3，28d抗压强度为5.0 MPa-20.0 MPa，导热系数为0.05-0.19 W/mk，可以满足不同功能需求。通过试验，分析研究了秸秆混凝土的收缩变形、抗霉变特性及吸水性等性能，并给出了降低其收缩变形特性的技术手段。通过室内试验与数值模拟技术，研究了秸秆混凝土在服役过程中的热工性能，提出了影响机制与调控方法。采用Maitab语言编制了计算程序，对秸秆混凝土建筑围护结构热湿迁移数学微分方程组、秸秆混凝土建筑室内空气温湿度数学模型以及秸秆混凝土建筑围护结构表面吸放量计算模型进行了数值模拟；采用数值建模，构建了多层结构植物秸秆混凝土墙，解析了由植物秸秆混凝土所构筑的墙体的热传导特性，明确了植物秸秆混凝土墙体具有调湿功能。本项目的研究内容与成果具有显著的创新性，对于推动秸秆混凝土的研究和发展具有重要的科学意义和实用价值，为农业与建筑业之间搭建了一个桥梁，实现建筑材料可再生，为下一代绿色建筑材料奠定理论基础。