Varying Aperture Long Slot (VALS), a Method for Studying Grout Penetrability into Fractured Hard Rock

摘要

This paper presents the design, manufacturing, and assembly of a new laboratory apparatus for investigation of grout filtration tendency and penetrability into rock fractures. The method makes it possible to examine grout samples composed of a wide range of cements and additives/admixtures with different water-to-solid ratios. The apparatus can be used to investigate the influence of different parameters on grout penetrability. Examples of these parameters include the cement particle size/distribution curves/chemical compositions, and the type and ratio of additives/admixtures that provide a variety of setting/hardening times, and rheological and strength properties. The grouting operation into the rock fractures is replicated using an artificial slot with 4-m-long constrictions varying from 230 to 10 mu m, and selective inlet and outlet. The apparatus can also accommodate grouting experiments under both static and dynamic pressure conditions up to 1,500 kPa to study their influence. Illustrative results are also provided.