THE MORTARS FOR DRILL-INJECTION PILES CREATION

The article presents information about development of the composition of the mortars which are based on cement and sand-cement with the addition of a superplasticizing admixture for performing well crimping during drill-injection piles creation. The need to develop new compositions of the mortars was opened due to the discovery of some defects in the experimental drill-injection pile shafts which were created by using cement mortar with the addition of liquid glass, after their excavation and examination. These defects (massive soil penetration into the pile shaft near its wellhead and soil and mortar mixing along the perimeter of the piles) are takes place owing the insufficient mortar density, its high shrinkage and low strength. The developed compositions are free of these cons and have increased value of mortar key parameters (density, strength, shrinkage) which is too important during the drill-injection piles creations. After laboratory tests which were done to identify the optimal ratio of mortar components and determine their main parameters, control tests of these solutions were carried out on the investigation site to check the possibility of their use on existing technological equipment. Field tests of the developed mortars confirmed the possibility of their use for drill-injection piles creation. Using the developed compositions of mortars drill-injection piles were successfully performed for the foundation strengthening on some objects in Tyumen.