Chemistry of Alkali-Silica Reaction

碱-硅反应（ASR）是混凝土劣化的主要原因。 本研究项目的总体目标是将联合收割机的化学和机械方法结合起来，以充分推进对ASR的基本理解，并为开发更有效的加速试验和预防损坏提供基础。目标是：1）了解ASR凝胶的分子和纳米尺度结构以及结构如何受到形成条件的影响，2）了解产生凝胶的分子和纳米结构过程，对凝胶组成的化学和结构控制，以及凝胶形成和随后转化的动力学，3）了解聚集体类型对ASR凝胶的组成和结构以及凝胶形成动力学的影响，4）了解控制溶胀行为的凝胶的化学和结构方面，（5）通过建立混凝土膨胀的有限元模型，了解ASR作用下混凝土宏观结构膨胀与凝胶形成和膨胀细节之间的关系，从而更有效地预测和评价ASR的工程效应，对土木工程、地质科学和材料科学具有重要的学术意义。它将提供一个重要的混凝土劣化机理的化学的详细理解，一类含水硅酸盐的分子结构的知识，ASR凝胶和建立分子结构和膨胀行为之间的联系。它将建立一个基于微观结构的模型，将ASR化学和混凝土膨胀联系起来。通过这项研究获得的知识将被纳入土木工程和地质学的教育中。该项目将加强工程和地质之间的相互作用。拟议中的研究将通过参与杰克逊州立大学，一个历史上的黑人机构，加强少数民族教育。

AbstractAlkali-silica reaction (ASR) is a major cause of concrete deterioration. The overall goal of this research project is to combine chemical and mechanical approaches tosubstantially advance fundamental understanding of ASR and to provide a basis for development of more effectiveaccelerated tests and for prevention of damage. The objectives are: 1) to understand the molecular and nanometer-scale structure of ASR gels and how the structure is affected by conditions of formation, 2) to understand themolecular and nanostructural processes that produce the gel, the chemical and structural controls on gelcomposition, and the kinetics of gel formation and subsequent transformations, 3) to understand the effects ofaggregate type on the composition and structure of ASR gel and on the kinetics of gel formation, 4) to understandthe chemical and structural aspects of gel that control swelling behavior, and 5) to understand the relationshipsbetween the macroscopic structural expansion of concrete undergoing ASR and the details of gel formation andswelling by developing a finite element model of concrete expansion that can be used to more effectively predictand evaluate the engineering effects of ASR.The proposed research will have intellectual impact in civil engineering, geological science, andmaterials science. It will provide a detailed understanding of the chemistry of an important concrete deteriorationmechanism, knowledge of the molecular structure of a class of hydrous silicates, ASR gel andestablish a link between molecular structure and swelling behavior. It will establish a microstructural-based modelthat links ASR chemistry and concrete expansion. Knowledge gained through this research will beincorporated into education in both civil engineering and geology. The project will enhance interactions betweenengineering and geology. And the proposed research will enhance minority education through participation Jackson State University, a historically black institution.