PATH: Functionally Graded Cement-Based Materials for Residential Construction

本研究计画以挤压法生产住宅建筑用水泥基材料，以制造功能梯度微结构，并量测与计算其工程性质。两个主要目标是：开发建筑组件（例如，壁板），其具有中心高度多孔且外表面致密的分级蜂窝状结构，从而降低密度而不产生通常与高度多孔材料相关的高渗透性和低强度，并生产部件（例如，梁），其具有分级的纤维增强，使得最高的纤维浓度出现在拉伸应变最大的梁的底部，从而通过有效地增强微观结构，利用具有较低总纤维体积的挤出水泥基复合材料中的纤维的实质性机械益处。多组分共挤出和多个挤出循环将用于加工这些材料。将使用扫描电子显微镜检查样品，以确定加工是否产生所需的微观结构。工程特性（模量，泊松比，强度，断裂韧性）将根据微观和宏观尺度计算。计算的性能将与测量的性能和观察到的微观结构进行比较，以证明计算的有效性并根据需要改进计算方法。拟议研究的一个相关的广泛影响是它有可能增加住宅建筑中先进水泥基材料的使用。这些材料比传统的木质材料有重要的优势这些材料比传统的木质材料有重要的优势（耐火性，耐久性），但是，它们的使用受到其高密度和低韧性的限制，这些问题直接由这项研究解决。一个工业咨询小组将帮助确保这项研究具有适当的创新性，工业可行性和经济可行性。拟议的研究也将影响教育，在土木工程课程中增加住宅建筑的学习，并使建筑材料的学习对建筑学学生有用。

This research project addresses the production of cement-based materials for residentialconstruction using extrusion so as to produce functionally graded microstructures and thenmeasure and compute the engineering properties provided by such microstructures. The two primary objectives are: to develop construction components (e.g., siding) with graded cellularstructures that are highly porous in the center and dense on the outer surface, thereby reducing thedensity without producing high permeability and low strength usually associated with highlyporous materials and to produce components (e.g., beams) with graded fiberreinforcement such that highest concentration of fibers occurs at the bottom of the beam wherethe tensile strain is greatest, thereby taking advantage of the substantial mechanical benefits offibers in extruded cement-based composites with a lower overall fiber volume through efficientengineering of the microstructure. Co-extrusion of multiple constituents and multiple cycles ofextrusion will be used to process these materials. Specimens will be examined using scanningelectron microscopy to determine whether the processing is producing the desiredmicrostructures. Engineering properties (modulus, Poisson ratio, strength, fracture toughness)will be computed based on microscopic and macroscopic scales. The computed properties will becompared with measured properties and with observed microstructures so as to demonstratevalidity of the computation and to refine the computational method as needed. A relevant broad impact of the proposed research is its potential to increase the use of advancedcement-based materials in residential construction. These materials have important advantagesover the more traditional wood-based materials (fire resistance, durability), however, their use hasbeen limited by their high density and low toughness, issues addressed directly by this research.An industrial advisory group will help assure that the research is suitably innovative, industriallyfeasible, and economically viable The proposed research will also impact education, adding studies of residentialconstruction in the civil engineering curriculum and making studies of construction materialsavailable to students in architecture.