A pasty clay–cement grouting material for soft and loose ground under groundwater conditions

Soft and loose ground is widely encountered in hydraulic engineering, civil engineering, mining engineering and so on. In treatment practices for this type of special ground, the general grouting materials used have a number of shortcomings, such as large consumption of materials and an unpredictable range of diffusion; it addition they are easily scoured by water. In this work a new grouting material was developed with pasty clay–cements to overcome the aforementioned problems with consideration of the specific structure and adverse environment of soft and loose ground. The rheological properties, setting times of the slurry and the mechanical characteristics of solidified grout stone were tested in a series of laboratory experiments. Compared with ordinary cement slurry and cement–clay slurry, the new material showed greater initial viscosity, adjustable thixotropy and setting time, a strong resistance to scour and a controllable diffusion range. An engineering application was analysed to illustrate that the new grouting material not only fulfils the requirements for grouting in soft and loose ground, but it can also be applied in soil layers with macrovoids as well as formations suffering from water soaking or scouring.