Rimantas Mackevičius

Influence of the pile stiffness on the ground slab behaviour

AbstractJust as other structural elements, ground slabs are an important unit of a building. It is especially true in the case of buildings, such as logistic centres, for which the primary purpose is storage of various goods. In this kind of buildings, floor slabs usually have high loads. For buildings where truck lifts are used, there are special requirements for flatness tolerance across and along the driving track of truck lifts. Therefore, the floor settlement differences in selected distances are limited. In localities where the soils under the floor slab are weak, they should be replaced or compacted. If these solutions are not possible or economically inappropriate, the slabs have to be supported on piles that must be based on strong deep soils. During the design process, it is very important to assign a proper value of rigidity of the piles. Pile stiffness has an enormous influence on the settlement of the slab as well as on the reinforcement intensity of the slab or even on the slab thickness. Th...

Research of cement additives influence on the properties of soilcrete

AbstractThe article analyses a possibility of replacing a part of cement with fly ash in jet grouting piles, because the received strength of cement treated grout is much higher than it is necessary for these piles. The paper presents the problems of fly ash utilization, overviews experimental and theoretical works and analyses laboratory tests on the samples of cement treated grout. The conducted experiments involved manufacturing cylindrical cement treated grout samples containing different additives when the diameter of the cylinder is 35 mm, and its height is 70 mm. The experiments on the samples comprising the additives of fly ash were made in sand and clay soils. 25% to 75% of cement was replaced with fly ash in cement treated grout samples tested under compressive strength following 7 days hardening in air.

Interaction between sandy deposits and multimolecular organic solutions by stabilisation of soil

AbstractThe paper presents the state of the art in grouting technologies for underpinning of old foundations, the analysis of grouting with multimolecular organic solutions and the results of investigations of dispersive soils stabilised with organic polymers over a period of one year. It describes the comparison between properties of unmodified carbamide resins and properties of modified carbamide resins. The following properties of resin solutions were investigated: density, viscosity, pH (alkalinity level) and evaporation of components from solution. The next stage of investigations involved the comparison of properties of alluvial medium dense sand stabilised with unmodified and modified resins.