Process for the preparation of a hydraulically hardening preparation and use thereof for filling a excavated cavity and in shield tunnel construction

摘要

Excavated earth from construction sites may be recycled as backfilling material or grout by incorporating it into a hydraulic composite. This is done firstly by blending excavated soil with a solidifying quantity of a hydraulic material and a fluidifying quantity of water and at least one first admixture selected from the group consisting of hydroxycarboxylic acids, phosphonic acid derivatives and saccharides and derivatives thereof, and blending the mixture thus created with a cement-dispersing agent at a time between the addition of the hydraulic material and the commencement of set of the hydraulic material. The hydraulic composites thus created have good fluidity, good final strength and low proneness to cracking.