膨胀型水泥硬化浆体变形的分形与粘弹性分析——含钙矾石和水镁石膨胀源的水泥硬化浆体的膨胀机理分析

Fractal geometry and viscoelasticity analysis of the deformation of expansive hardened cement paste :analysis of the expansive mechanism of hardened cement paste with double expansion sources of entringite and brucite

应用分形学与粘弹性力学对含钙矾石和水镁石膨胀源的水泥硬化浆体的膨胀机理进行了研究与分析。得到在这种膨胀型水泥硬化浆体中的钙矾石和水镁石膨胀随SO3与MgO质量分数和时间的变化规律 ;揭示了膨胀型水泥硬化浆体的分形行为 ,其膨胀曲线的分形元服从指数规律 ;解释了在钙矾石膨胀的基础上水镁石膨胀的非线性叠加现象 ;解释了来自钙矾石和水镁石的结晶膨胀能不可能全部用作膨胀功 ,而是部分消耗在变形过程中 ,部分贮存在水泥硬化浆体中 ,部分用于使水泥硬化浆体结构致密化的膨胀规律。

The expansion mechanism of hardened cement paste with double expansion sources of entringite and brucite was studied by using theory of fractal geometry and viscoelasticity. Results indicated that the variation of entringite and brucite expansion in the hardened cement paste was obtained with variable gypsum and periclase. Furthermore it was revealed that the fractal unit of structures of expansive hardened cement paste was KELVIN viscoelastic solid; the fractal unit of their expansive curves obeyed exponential law; and the dimension of expansive curve was ln2/ln2cosα>1 (0<α<90°). It was explained that on the basis of entringite expansion at early age the expansion from producing brucite at late age was nonlinear addition. And it was explained that the whole of expansion energy from entringite and brucite crystallization could not have done expansion work; and one part of it was consumed in the deformation process; a secondpart was stored in the paste; and the remainder part made the structure of hardened cement paste compacted.