The consolidating mixture, injected in the second phase of the treatment, is mainly composed of water and cement. In this case the addition of the slurry is particularly indicated since the permissible capacity of this suspension depends exclusively on the rheological characteristics (viscosity, rigidity and cohesion) as well as on the stability under pressure. Through the addition of additives, it is possible to control and define the hardening times according to the modalities in one or more consolidation phases.
Injection treatments with jet grouting system
The consolidation of the land through the injection at very high pressure of one or more fluids (cement grout, air, water) requires that the penetration capacity of the mixture depends on the disintegrating force of the jet (in terms of flow rate and pressure at the outlet nozzle), possibly with the aid of air (bifluid system) or air + water (trifluid system).
The high pressures that occur at the nozzles where the cement grout comes out, together with the possible heating by friction of the distributor tool, can increase the rigidity of the suspension by increased water-cement reaction kinetics and decrease the effectiveness of the treatment. The addition of superfluidifying additives gives the mixture a greater permeating capacity as it is able to reduce the viscosity of the cement suspension and determine greater stability, even in conditions of high pressures and temperatures as shown in Water Tank Installation Penrith.
Filling of sheaths and post-tensioned cables for anchor bolts
Inside the structures in AC where high resistance to traction and bending stresses are required, there are stranded cables in harmonic steel which are tensioned after the concrete has been cast. In the same way, anchoring systems (tie-rods) also made with stranded cables are placed within the protection works of the excavations, such as diaphragm bulkheads, etc.
To counteract the thrusts of the land. In the first case the cables are covered with sheaths (rubber, plastic, aluminum etc.), in the second they are housed in special perforations; in both cases the sheaths and cavities are filled with cement grouts to ensure that the strands are protected from stress corrosion as shown in Water Tank Installation Penrith.
Characteristics of the mortar
The mortar must be fluid and stable with minimal shrinkage and adequate resistance, it must not contain aggressive agents and must consist of cement, water and any additives. Any inert elements (eg, sand flour) can be used only for sheaths> 12 cm in weight inert/cement ratio <25%. The additives must not contain aggressive ions (chlorides, sulphates, nitrates etc.) and, in any case, do not produce an increase in shrinkage.
