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Item type:Publication, Access status: without files , Untersuchungen an Verpressankern in calcitabscheidendem Wasser(Ernst & Sohn, 2026-03-26); ; ; ; Investigations on grouted anchors in calcite-precipitating water. As part of a research project, model-scale grouted anchors were produced in sands and analysed with regard to their pull-out resistance up to a storage period of twelve months. Tap water, which, based on water analyses, is classified as calcite-precipitating, was used to flow around the anchors. Tension load tests were conducted on the grouted anchors. The results indicated that the ultimate limit state increased significantly after a storage period of six months, and further increase was observed after twelve months. After excavating, an additional layer of material with a thickness of up to three millimetres was identified on the surface of the grout body. It was observed that this layer increased in strength with an extended duration of storage. Analyses demonstrate that, within the contact zone between soil and cement paste, ions from the pore solution of the cement paste react with the calcium ions and carbonate ions present in the tap water, resulting in the formation of calcium carbonates. These carbonates form a matrix including the surrounding sand grains, which becomes stiffer over time.Publicationtype: Journal Article12 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Effect of grouting on the hydration and microstructure of portland cement and release of environmentally relevant substancesGround 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.Publicationtype: Conference Paper42