skip to main content

Search for: All records

Award ID contains: 1846984

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?

Some links on this page may take you to non-federal websites. Their policies may differ from this site.

  1. Free, publicly-accessible full text available August 1, 2024
  2. The effect of in-house synthesized hydrogels with different chemical compositions on the properties of alkali-activated slag pastes was examined. It was found that the teabag test and modified teabag test as a direct method and the flow test as an indirect method showed a similar trend in hydrogel absorption; however, the absorption values differ noticeably between the direct and indirect methods. The alkali-activated slag pastes with hydrogels demonstrated a significant reduction in autogenous shrinkage compared to the pastes without hydrogels. The creation of macrovoids by the hydrogels and change in pore structure resulted in a decrease in compressive strength and electrical resistivity of the pastes with hydrogels. The absorption and desorption of hydrogels in the pastes were tracked using X-ray microcomputed tomography (micro-CT), and it was shown that the onset of hydrogel desorption approximately coincided with the final setting time of the pastes. 
    more » « less
  3. null (Ed.)
    The effect of hydrogels containing nanosilica (NSi) on the autogenous shrinkage, mechanical strength, and electrical resistivity of cement pastes was studied. The interaction between the hydrogels and the surrounding cementitious matrix was examined using thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The addition of hydrogels decreased autogenous shrinkage in the cement pastes and this reduction showed a dependence on the concentration of NSi in the hydrogels. Compressive strength and electrical resistivity were reduced in the cement pastes with hydrogels and this reduction was decreased with increased concentration of NSi in the hydrogel. A change in the phase composition of the cement paste in the region close to the hydrogel was noted, compared to the region away from the hydrogel. In a lime solution with increased pH and temperature, Ca(OH)2 and CaCO3 were found to form within the hydrogels; evidence of calcium-silicate-hydrate (C-S-H) formation in the hydrogels with NSi was obtained, indicating the possible pozzolanic potential of the hydrogels with NSi. 
    more » « less