Analysis on the expansion mechanical characteristics and anchoring force evolution of self-expanding anchorage body

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Adding a large proportion of a self-expanding agent11SEASelf-expanding agent (SEA) to a plain cement slurry under limited space conditions can greatly improve its anchoring force. This effect is closely related to the type and dosage of the SEA. Therefore, various types of self expanding cement22SECSelf-expanding cement, which refers to cement mixed with accelerator and a large amount of self-expanding agent(SEC) have been proposed, and the XRD, XRF and basic property testing experiments using a customized mold and steel pipes were used to examine the composition and mechanical properties and the self-expanding cement anchorage body33SEBSelf expanding cement anchorage body, which refers to solid formed by the reaction of self expanding cement with a certain proportion of water (SEB). The chemical structure composition, mineral compositions, expansion pressure, uniaxial compressive strength, fundamental mechanical properties, and ultimate anchoring force generated by SEB under different experimental conditions are analyzed. The results showed the following. (1) The expansion pressure of the SEB peaked and then gradually stabilized within 1–2 days. SEA proportions of 5–15% provided a greater stable expansion pressure. (2) When the dosages of the SEA were within 15%, adding three types of SEA to plain cement effectively improved the uniaxial compressive strength of the SEB. (3) The SEA greatly improved the anchoring force. The CSA, HSCA, and UEA SEBs had the highest anchoring force when the dosages were 20%, 20%, and 15%. The peak anchoring forces were 190.3, 185.1, and 125.8 kN, respectively, increases of 107.3%, 101.6%, and 37.0% compared to plain cement anchorage body.