6 Materials and products

6.1 General

6.1.1 All grout components and grouts shall comply with the specifications for the works and the relevant EN or national standards.

6.1.2 The compatibility of all grout constituents shall be evaluated. Similarly, an assessment shall be made of the possible interaction between the grout and the ground.

6.1.3 Once established, the sources of grout materials shall not be changed without prior compliance verification or testing.

6.1.4 Materials that do not meet agreed quality standards shall promptly be removed from the site.

6.2 Grout materials

6.2.1 Hydraulic binders and cements Hydraulic binders include all cements and similar products used in water suspension for making grouts. Microfine (ultra-fine) hydraulic binders or cements are characterized by a particle size d95 of less than 20 µm. The granulometric curve, especially of the microfine products used, shall be known. When selecting the type of hydraulic binder for grout, its grain size distribution should be considered in relation to the dimensions of the fissures or voids of the ground to be treated. Cements are subject to prEN 197-1:2000 and prEN 197-2:2000. Methods for testing of cements are subject to EN 196. Properties and methods different from those mentioned in those standards and specific to grouting are subject of this standard.

6.2.2 Clay materials Natural clays, activated or modified bentonites can be added to cement based grouts in order to reduce bleeding and filtration under pressure, to vary the viscosity and cohesion (yield) of the grout, or to improve the pumpability of the grout. The mineralogy, particle size, water content, and Atterberg liquid limit of the clay should be known.

6.2.3 Sands, gravels and fillers Sand and fillers are commonly used in cement grouts or clay suspensions as bulking agents or as a means of varying the consistency of the grout, its resistance to wash-out, or its mechanical strength and deformability. Natural sands or gravels may be added to grouts, provided that they do not contain any harmful components. The granulometry of sands and fillers used in grouts shall be known.

6.2.4 Water Water obtained from natural sources on-site should be tested (particularly for chlorides, sulphates and organic matter) and approved. Sea water can be used provided that the properties of the grout mix are not impaired.

6.2.5 Chemical products and admixtures Chemical products such as silicates and their reagents, lignin based materials, acrylic or epoxy resins, polyurethanes or others can be used in grouting work subject to compliance with environmental legislation. The effects of all products and by-products resulting from reaction of the chemical products with other components of the grout or with the surrounding ground shall be considered. Admixtures are organic or inorganic products added in small quantities during the mixing process in order to modify the properties of the grout and to control grout parameters such as viscosity, setting time, stability, and strength, resistance, cohesion and permeability after placement. Admixtures to grout such as superplasticizers, water retaining agents, air entrainers and others are subject of Parts 1, 3, 4 and 6 of prEN 934 and prEN 480-1 to 480-12.

6.2.6 Other materials Calcareous or siliceous fillers, pulverized fuel ash (pfa), pozzolans and fly ash from thermal power plants or any inert or reactive components may be used in grouts, provided that they are chemically compatible with each other and satisfy immediate and long term environmental requirements. Methods for testing of fly-ash are subject to ENV 451. Methods different from those mentioned in that standard and specific to grouting are subject of this standard.

EN 12715:2000 Execution of special geotechnical work – Grouting