SBIR Phase I: Low-Cost Glass Fiber Composites Tailored Towards Concrete Reinforcement

这个小企业创新研究（SBIR）第一阶段项目旨在开发一种新型的低成本玻璃纤维复合材料，这种复合材料与混凝土的高碱性环境兼容。这些复合材料中的聚合物基体包含离子交换聚合物的精细分散，用于降低扩散混凝土孔隙水的碱度。离子交换聚合物是通过将极性基团连接到聚合物基体上制备的；它们现在以相对较低的成本生产，用于过滤器和调理器。含有离子交换聚合物的基质可以作为分子筛，从孔隙溶液中去除碱金属离子，从而保护玻璃纤维免受碱侵蚀。初步分析表明，在混凝土复合钢筋的情况下，离子交换聚合物具有将混凝土孔隙水的碱度降低到不侵蚀玻璃纤维的水平的能力。传统热固性玻璃纤维复合材料基体与离子交换聚合物的共混有望改变玻璃纤维复合材料的良好经济性。这将有助于大规模采用复合材料作为混凝土中钢筋的防腐蚀和真正耐用的替代品，并注意到碳和芳纶纤维复合材料的成本相对较高，限制了它们用作混凝土中钢筋的潜力。所制备的复合材料在力学性能、与混凝土的粘结强度、成本等方面应满足混凝土钢筋的要求，并在不同暴露条件下的混凝土碱性环境中具有化学稳定性和尺寸稳定性。该技术的潜在商业应用包括受腐蚀环境影响的钢筋混凝土系统，包括桥梁结构、停车坡道和海上结构。

This Small Business Innovation Research (SBIR) Phase I project seeks to develop a new class of low-cost glass fiber composites that are compatible with the highly alkaline environment of concrete. The polymer matrix in these composites incorporates a fine dispersion of ion-exchange polymers for reducing the alkalinity of diffusing concrete pore water. Ion-exchange polymers are prepared by attaching polar groups to polymeric matrices; they are now produced at relatively low cost for use in filters and conditioners. The matrix incorporating ion-exchange polymers can feasibly act as a molecular sieve that removes alkali metal ions from the pore solution, and thus protects glass fibers against alkali attack. Preliminary analyses suggest that ion-exchange polymers possess the capacity, in the context of composite reinforcement in concrete, to lower the alkalinity of concrete pore water to levels that are not aggressive against glass fibers. Blending of conventional thermoset matrices of glass fiber composites with ion-exchange polymers promises to alter the favorable economics of glass fiber composites. This would facilitate large-scale introduction of composites as corrosion-proof and truly durable replacement for steel in concrete, noting that the relatively high cost of carbon and aramid fiber composites limit their potential for use as reinforcing bars in concrete. The resulting composites should meet the demands on concrete reinforcement in terms of mechanical performance, bond strength to concrete and cost, and should also be chemically and dimensionally stable in the alkaline environment of concrete under diverse exposure conditions. Potential commercial applications of the technology cover reinforced concrete systems subjected to corrosive environments, including bridge structures, parking ramps and offshore structures.