دانلود رایگان مقاله مدل سازی عددی مواد مبتنی بر سیمان متخلخل توسط پلیمر ابر جاذب

ABSTRACT

The development of new cementitious materials raises new challenges with regard to structural design. One of the potential applications of superabsorbent polymers (SAP) is to deliver well-defined porosity to cement systems. This is particularly interesting for the development of porous cement-based materials with high technical performance. In this paper, a numerical approach to model the basic mechanical properties of the porous cement with SAP is developed. The modelling approach is based on computational micromechanics and uses a representative volume element that emulates the microstructure of the cement-based material to determine the overall material response and the local behaviour. Using this approach several sensitivity analyses are undertaken examining various parameters. The modelling approach is compared with experimental results showing reasonable correlation. The proposed approach provides faster and cheaper tool to design porous materials due to a reduction in the required experimental effort.

7. Conclusion

A 3D modelling approach based on computational micromechanics is presented to predict the mechanical behaviour of porous cement-based materials by SAP. The proposed approach provides a quantitative means to estimate and predict the mechanical properties of porous cement materials taking into account the micro-structure.The results indicate that the elastic and tensile strength predictions are satisfactory using, in the material model adjustment, the characterization of the cement paste without SAP. However, for obtaining a good prediction of the compressive strength, the material model has to be fitted using the characterization of any case with SAP voids in order to indirectly include the intrinsic porosity associated with the cement paste. The relation between the mechanical property and the porosity is well fitted by a power-law equation, both for experimental and numerical predictions, being fitted the parameters in the same range that has previously been found out by other researchers for other type of cement-based materials.