Introducing pozzolanic admixture to improve frost resistance of pavement concrete

International Conference on Construction, Architecture and Technosphere Safety 2018

土木建筑工程

Kramar, L.Ya.^1 ; Kydyakov, A.I.^2 ; Shuldyakov, K.V.^1

Building Materials and Products, South Ural State University, Lenin Avenue, 76, Chelyabinsk

454080, Russia^1

Building Materials and Technologies, Tomsk State University of Architecture and Building, Solyanaya Sq., 2, Tomsk

634003, Russia^2

关键词: Complex admixture;    Concrete strength;    Micro-capillaries;    Multicomponent mixture;    Pavement concrete;    Polycarboxylate superplasticizer;    Structure durability;    Thermal deformation;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/451/1/012009/pdf
DOI  :  10.1088/1757-899X/451/1/012009

学科分类：土木及结构工程学

来源: IOP

【 摘 要 】

Concretes with the w/c ratio less than 0.35 that consist of multicomponent mixtures are highly resistant to frost aggression, which increases structure durability. It is generally accepted that cyclic freezing of structures in a saturated state causes concrete disintegration due to ice formation in macro and microcapillaries. The samples of high-performance concrete, experimentally frozen at minus 50 °C and thawed at 20 °C in a 5 % solution of NaCl, dried by themselves, which made ice formation unlikely. The mass of the frozen samples changed approximately the same way as the mass of the control samples, and only after a certain number of cycles the main samples started to sharply gain in mass and lose strength. Moreover, the tested samples showed only slight penetration of moisture deep into the concrete, while its core remained dry. This allows us to assume that when testing the frost resistance of highly functional concrete samples, their disintegration was caused by thermal deformations with practically no ice formation. The use of plasticizers slightly changes the concrete strength to frost resistance, and only a complex admixture, containing superplasticizer and silica fume, allows this factor to be increased 2-3 times. Most effective is a complex of pozzolana and a polycarboxylate superplasticizer.