Effect of grouting on the hydration and microstructure of portland cement and release of environmentally relevant substances

Start Page
1126
End Page
1135
Citation
6th fib International Congress on Concrete Innovation for Sustainability (2022)
Contribution to Conference
6th fib International Congress on Concrete Innovation for Sustainability, 2022 
Scopus ID
2-s2.0-85143901284
Ground anchors are frequently used in foundation engineering. During manufacturing cement suspension is filled in a borehole and subsequently grouted. In non-cohesive soils, grouting leads to a filtration process, where the mixing water is pressed out from the cement suspension and a so-called “filter cake” is formed. The scope of the experimental investigations are ground anchors from a large-scale experiment and grouted and neat cement pastes from laboratory tests. The hydration process and microstructure of the hardened grouted cement paste have been investigated in comparison to grout bodies from the large-scale experiment. Elution tests were carried out to determine the leaching behaviour of both the neat cement paste and the grout bodies. Furthermore, filtered mixing water from laboratory test samples were analysed. The porosity was determined by water absorption under atmospheric pressure and mercury intrusion porosimetry (MIP). The hydration process was investigated by using thermogravimetric analysis (TGA). The composition of the filtered mixing water and the results of the leaching tests allowed to assess the impact of the grouting process on the surrounding soil and groundwater from an environmental point of view. This paper concludes with an evaluation of the effect of the grouting process. The results from the experimental programme are compared between grouted and neat cement paste as well as for grout bodies. The conclusion is completed by consideration of environmental aspects.
Schlagworte
Cement paste
grouting
microstructure
pore size distribution
thermogravimetric analysis