基于非均匀界面过渡区模型的淘洗粉煤灰混凝土弹性模量预测

Zhao Xiaoping, Zhan Misha, Chen Zhiwei, Zhang Jian, Li Qiang, Song Wenbing

Architectural Engineering College, Jinhua University of Vocational Technology, Jinhua 321016, China.

Jiyang College, Zhejiang A&F University, Shaoxing 311800, China.

Materials (Basel). 2025 Aug 12;18(16):3779. doi: 10.3390/ma18163779.

The incorporation of fly ash into concrete reduces cement consumption by 10-30%, lowers CO emissions by 30-50%, cuts costs by 15-25%, and enhances durability, thus reducing maintenance expenses. However, the predictive model for the elastic modulus of fly ash concrete subjected to calcium leaching is still lacking. Regarding the theoretical method, the content of calcium hydroxide and calcium silicate hydrate in fly ash-cement systems is quantitatively calculated according to the hydration reaction relationship between cement, fly ash, and water, and then the porosity of the fly ash-cement matrix and interface transition zone (ITZ) after calcium leaching can be obtained. Based on the theory of two-phase composite spheres and the non-uniform ITZ model, the prediction method for the elastic modulus of leached fly ash concrete can be constructed, which comprehensively considers key parameters such as fly ash content, non-uniform characteristics of the ITZ, and the water-binder ratio (w/b). Additionally, the corresponding experimental investigation is also designed to study the variation regulation of the leaching depth, leaching extent, and elastic modulus of fly ash concrete with leaching time. The prediction method for the elastic modulus of leached fly ash concrete is validated via self-designed experimental methods and third-party experiments. This study further delves into the specific effects of w/b, aggregate volume fraction (f), fly ash content, and ITZ thickness (h) on the elastic modulus of leached concrete (E). The research findings indicate that an appropriate amount of fly ash can effectively enhance the leaching resistance of concrete. For a leaching degree of 10.0%, 30.0%, and 50.0%, E at w/b = 0.40 exceeds that of w/b = 0.60 by 26.71%, 28.43%, and 30.28%, respectively; E at h = 10 μm exceeds that of h = 50 μm by 16.96%, 15.80%, and 15.11%, respectively; and E at f = 65% is 39.82%, 43.15%, and 46.12% higher, respectively, than that of concrete with f = 45%. Furthermore, a linear correlation exists between the elastic modulus and the degree of leaching. The prediction method for the elastic modulus offers a theoretical foundation for in-depth exploration of the durability of leached mineral admixture concrete and its scientific application in practical engineering.

将粉煤灰掺入混凝土中可减少水泥用量10%-30%，降低二氧化碳排放量30%-50%，削减成本15%-25%，并提高耐久性，从而降低维护费用。然而，仍缺乏针对受钙溶蚀影响的粉煤灰混凝土弹性模量的预测模型。在理论方法方面，根据水泥、粉煤灰和水之间的水化反应关系，定量计算粉煤灰-水泥体系中氢氧化钙和硅酸钙水化物的含量，进而得到钙溶蚀后粉煤灰-水泥基体及界面过渡区（ITZ）的孔隙率。基于两相复合球体理论和非均匀ITZ模型，构建受溶蚀粉煤灰混凝土弹性模量的预测方法，该方法综合考虑了粉煤灰含量、ITZ的非均匀特性和水胶比（w/b）等关键参数。此外，还设计了相应的试验研究，以探讨粉煤灰混凝土的溶蚀深度、溶蚀程度和弹性模量随溶蚀时间的变化规律。通过自行设计的试验方法和第三方试验对受溶蚀粉煤灰混凝土弹性模量的预测方法进行了验证。本研究进一步深入探讨了w/b、骨料体积分数（f）、粉煤灰含量和ITZ厚度（h）对受溶蚀混凝土弹性模量（E）的具体影响。研究结果表明，适量的粉煤灰可有效提高混凝土的抗溶蚀性。对于溶蚀程度为10.0%、30.0%和50.0%的情况，w/b = 0.40时的E分别比w/b = 0.60时高出26.71%、28.43%和30.28%；h = 10μm时的E分别比h = 50μm时高出16.96%、15.80%和15.11%；f = 65%时的E分别比f = 45%的混凝土高出39.82%、43.15%和4...12%。此外，弹性模量与溶蚀程度之间存在线性相关性。弹性模量的预测方法为深入探究受溶蚀矿物掺合料混凝土的耐久性及其在实际工程中的科学应用提供了理论基础。