ISSN 0862-5468 (Print), ISSN 1804-5847 (online) 

Ceramics-Silikáty 65, (3) 273 - 280 (2021)


THE EFFECT OF CRYSTALLIZING ADMIXTURE ON THE PROPERTIES AND SHRINKAGE OF CONCRETE
 
Nagrockiene Džigita, Pundiene Ina, Čepulis Audrius, Pocius Edvinas
 
Vilnius Gediminas Technical University, Sauletekio av. 11, Vilnius, LT-10223, Lithuania

Keywords: Crystallizing admixture, Concrete, Shrinkage, Compressive strength , Porosity
 

This study investigates the effect of the amount (from 0.6 % to 1.4 %) of crystallizing admixture (CA) on the shrinkage, density, porosity and mechanical properties of concrete specimens. A higher content of CA increased the total porosity of concrete from 10.6 % to 11.15 %. In contrast to the specimens containing 0.8- 1.0% of CA, the lowest amount of closed pores and highest total porosity was observed in the specimens containing 1.2 %-1.4 % of the CA. Compared to the control specimen, concrete specimens containing 1.4 % of CA showed a 5.4 % decrease in flexural strength and a 13.6 % decrease in compressive strength after 28 days of curing. The specimens containing 0.9 %-1.0 % of CA demonstrated the lowest shrinkage in the period of 190 days. The shrinkage of these specimens reduced 4.8 %-4.9 % compared to the control specimen. Higher content of CA had an opposite effect on the shrinkage, a short-term expansion of specimens was observed after 28-56 days. Taking into account all the properties of the concrete specimen, the optimum amount of CA, which could prevent cracks in the structures is 1.0% of the cement mass.


PDF (1.5 MB)

doi: 10.13168/cs.2021.0028
 
 
Licence Creative Commons © 2015 - 2022
Institute of Rock Structure and Mechanics of the CAS & University of Chemistry and Technology, Prague
Webmaster | Journal Contact