Materiał wypełniający z popiołem lotnym i żużlem jako środkiem smarnym w przeciskaniu rur pod kwaśnymi gruntami siarczanowymi

The pipe jacking method is relatively reasonable among trenchless construction methods. For the application of this method, the acid sulfate soils have negative impacts on filling materials (one of the cement materials) injected into the tail-void which are over-cutting areas formed to reduce the friction between the pipes and the surrounding soils. In this study, the application of fly ash and slag is discussed to minimize the effect of sulfur acid to filling materials. As the results of the experiments, the addition of fly ash and slag can control the gelling time and prevent the reduction of uniaxial strength of filling materials under the acid sulfate soils. In addition, the filling materials added slag lowered frictional resistance compared to that of fly ash. Filling materials with the lower frictional resistance are preferred to apply for the smooth pipe jacking constructions. Therefore, filling materials added slag would show better performance than that of fly ash under the acid sulfate soils due to its lower frictional resistance.