Untersuchungen an Verpressankern in calcitabscheidendem Wasser

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.

Subjects

cement paste

grouted anchor

Portland cement

pull-out resistance

DDC Class

690: Building, Construction

Options

Untersuchungen an Verpressankern in calcitabscheidendem Wasser