The structure of hardened cement paste changing due to mineral admixtures

7th International Symposium Actual Problems of Computational Simulation in Civil Engineering

土木建筑工程;计算机科学

Il'Ina, L.V.^1 ; Tulyaganov, A.K.^1 ; Gichko, N.O.^1 ; Teplov, A.N.^1

Novosibirsk State University of Architecture and Civil Engineering (Sibstrin), Leningradskaya st. 113, Novosibirsk

630008, Russia^1

关键词: Characteristic length;    Crystalline structure;    Hardened cement paste;    Maximum strength;    Mineral additives;    Mineral admixtures;    Shrinkage pores;    Total pore volume;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/456/1/012043/pdf
DOI  :  10.1088/1757-899X/456/1/012043

来源: IOP

【 摘 要 】

The effect of a dispersed mineral additive (limestone) on the structure and the strength of hardened cement paste was investigated. It was shown that a dispersed mineral admixture significantly influences on the hardening of cement paste. To obtain the maximum strength, the optimum quantity of additive is 7%, it gives an increase in the strength of hardened cement paste by 22%. It was shown that when the limestone is added, there are significant changes in the structure of hardened cement paste. The number of pores with a diameter less than 1.2 microns increases, the total pore volume and the total pore surface also increase. This enlarges the characteristic length of pores and reduces the tortuosity of pores. In a cement paste with no admixtures, the structure is loose enough, with a large number of shrinkage pores with a size of up to 0.05 mm. The hardened cement paste with admixed dispersed limestone has a denser, more homogeneous fine-crystalline structure with a small quantity of pores in all investigated periods of hardening.