Recipe development and field evaluation of cement-based grout for rock

Development of recipes for optimal performance in terms of penetration capacity and ensuring that existing environmental requirements are met.

The purpose of the development of cement-based grouting recipes in the laboratory is to ensure a well-functioning product on site during tunnel construction and prior to subsequent preliminary testing. A recipe developed by RISE and the client is checked and refined on site for optimal grouting in existing rock fracture systems before and during tunnel construction. The set of laboratory and field quality-assured testings are conducted as smoothly as possible, so that that the environmental requirements for water ingress during construction are met.

An optimized recipe, developed in a laboratory, contributes to good  grouting performance and after final field optimization a minimum amount of water flow is achieved that is added to the tunnel per unit of time, and often is expressed as a requirement per unit of time in number of liters or droplets per unit of time.

An optimized grout also acts as additional stabilization of fractured rock sections, where the cement-based grout contributes to traditional  rock mass stabilization  with rock bolts.

Methods - standardised protocols

The following standards are taken into account when developing recipes: EN 14497, EN ISO 10414-1, EN ISO 10414-1, SS-EN ISO 17892-12:2018

RISE offers a developed recipe in laboratory conditions and final product inspection in the field.

The approach is based either on calibration of the existing recipe  in a laboratory conditions or developing composition from scratch, which can be refined in field conditions later.

The service also involves quality control of existing grout that is already used during ongoing grouting on site.

The customer is offered a quality-assured product from start to finish, where a report of variation in quality is reported.

The customer receives field documentation and a complete report