The quick development of technology in the recent years is also visible in the broadly understood construction industry. For designers and contractors, the actions of groundwater were always an issue causing limitations at the erection of both overground and underground structures. The need to combat these particular requirements has contributed to the new developments within modern monolithic structure insulation systems. A modern approach turned out to be the use of injection hose systems in the 1980s. Ever since, numerous products of similar nature emerged, the mode of installation and functional characteristics of which differ greatly at times.
Looking at the entire system from the point of view of its operation, the hose itself only serves as a technical resource, with the use of which the appropriate sealing product is introduced into the day joint.
The effectiveness of the entire system should be provided by the chosen injection material, and that is why, before this choice is made, one needs to acquaint themselves with the range of use and maximum allowable pressure for the relevant materials. One should note parameters and criteria to be fulfilled by the hose, and find out about the rules of correct assembly of the injection hose system. Its main advantage is the lack of necessity of planning out the entire system in the site design phase.
During installation of injection hoses, one does not need to interfere in the reinforcement or formwork, and the installation itself takes place on the slab executed earlier. An important factor influencing such insulation is the small cross-sectional size of the hose that may be used for day joints of thin components (caring to provide a concrete cover not under 7 cm on both sides), and as additional insulation in conjunction with insulation bands.
|Diagram of penetration of day joint by groundwater.||Diagram of insulation of day joint by injecting through an installed P-100 hose.
|System iniekcyjny P-100
|P-100 injection hose||100 mb/roll
|PVC injection nozzle||50 pcs./bag
|Quicky connectors||25 pcs./bag
|Wąż ciśnieniowy zbrojony PCV (biały)
|Injection nozzle 55 mm
|STECKY grip||100 pcs./bag
|Installation mounting box
||1 pcs.||1 pcs.||pcs.||0,250
|PK-2 Installation mounting box||1 pcs.||1 pcs.||pcs.||0,250
|Assembly grip||300 pcs./bag
P-100 injection hose
|The P-100 injection hose is built of a rectangular elastic core, with a centrally-located transport channel to provide the injection material. Along the sides of the P-100 hose are found microfractures allowing the injection material to exit. An appropriately designed structure of the hose prevents flooding of the interior of the transport channel by bleeding water.|
|Plastic Quicky connectors allow fast connections of sections of the injection hose with the pressure hose. Their structure does not require the use of any tools and allows work in protective gloves.|
PVC injection nozzle
|The shape of the PVC injection nozzle allows fast assembly of the P-100 injection hose by squeezing into the adaptor and by protecting it against slipping out through the use of a movable ring. The flat installation strip allows mounting the end nozzle to the formwork using nails. Do not the plug protecting the thread before concreting work.|
Reinforced pressure hose (white)
|The reinforced hose ensures that further sections of injection hoses can exit outside of the outline of the reinforced concrete component. It is designed to withstand injection material pressures between 10 bar and 30 bar (appropriate value indicated on jacket).|
|Appropriately shaped assembly grips ensure close adherence of the hose to the base layer. The opening in the grip allows easy affixing to the base layer using concrete nails or quick connect bolts.|
Installation mounting box
|An installation component, to which PVC pressure hoses should be routed. The boxes are usually mounted to rebar or to formwork.|
|The nipple, or fitting, is used to achieve an appropriate connection of the injection hose with the pressure equipment and the machine pumping the injection material.|
Injection materials are the real sealing compound that, when injected through the transport channel of the hose to slits emerged at day joints during concreting, fills them up and prevents possible leaks or capillary water creep. Available are single-component, dual-component or multi-component resins, gels or cement suspensions. Depending on the shape of the sealed component and the general task to be done by the insulation, one has to select appropriate injection material with a precisely chosen chemical composition and hardening reaction procedure.
Injection hose systems are characterised by easy assembly and flexible adaptation to day joints with complex shapes. The injection hose is arranged usually in the centre of the day joint (fig. 1). If the sealed component has a width exceeding 60 cm, it should be laid out at a separation of approx. 25 cm from the direction of water inflow.
For components, the thickness of which exceeds 40 cm, and in case of possibility of great water pressures, one could possibly consider utilising two parallel hoses. In such a case, one should remember to cover the concrete appropriately (at least 7 cm) for each hose. When arranging the injection hose system, the contractor has to care for the injection hose itself not to pass too close to the face of the component to be concreted at no point, and even more, for the hose not to protrude outside of its outline.
In order to effectively prevent hose shifting during concreting, it should be mounted to the base layer using installation grips, spaced approx. 25 cm apart (approx. 4-5 grips per hose running metre). The length of an individual hose section, used for sealing joints, should not exceed 10-12 r. m. Should there be corners or bends of the component to be sealed along the injection hose route, it is recommended to reduce section length to 10 running metres.
It is important for the hose to be routed along the simplest possible route, if possible, without loops. If it should become necessary to arrange the hose along a curve, one has to make sure that the maximum bend angles for the relevant product are not exceeded. An important factor influencing the tightness of the entire system are spots where a subsequent hose section is added. In order for these key spots to be appropriately tight, one should take care that the hoses are joined using overlays, and for their parallel sections be spaced at least 5 cm from each other.
Similarly, at spots, where the sealed components shift from horizontal to vertical, system seals may be damaged. In order to execute the injections properly at these corners, and not to bend the hose all too much, which could cause it to fracture or the transport channels to be blocked, it should be routed through extrusions executed on convex corners (fig. 3).
Additional protection of edges of the components to be sealed may be achieved by routing the hose along a short section, in a concave corner, and aiming it towards the tip in the form of an elongated letter 'S'. An important aspect in terms of the work is joining sealing bands and the injection hose system together to form a reliable seal system. When installing injection hoses at intersections of day joints and expansion joints, sealed by expansion bands, one should route the hose to the concreted part of the band (fig. 4).
Difficulties in adhering to this rule can be seen in situations when expansion joints were sealed by external tape bands. We advise against the use of such sealing material combinations (fig. 5).
|Fig. 2. Subsequent hose sections intersecting.||Fig. 3. Hose layout in corners.|
|Fig. 4. Hose layout at expansion joints sealed by internal sealing bands.||Fig. 5. Hose layout at expansion joints sealed by external sealing bands.|
Injection of concreted hoses
When executing the injection, one needs to remember a few important basic rules. The high pressure required when the material is injected may damage the hose transport duct or the structure to be insulated itself. In order not to cause any damage, the injection needs to be done at a fixed pressure, the value of which should be stabilised within as low a range as possible allowing the transport of the injected material. Another important factor preventing injection is low ambient temperature around the concreted component. Work at a temperature below +5 °C may be ineffective and unsuccessful in terms of speed and correctness of the reactions taking place during hardening of the injection material. Before commencing work, and even before choosing the injected material, one needs to study the technical details and recommendations of the manufacturer carefully.
|Step 1. First stage of structure concreting.||Step 2. Choosing the hose path along the joint to be insulated.|
|Step 3. Division of the injection hose into sections of the appropriate length and attachment to the concreted structure.||Step 4. Attachment of pressure hoses to the ends of the individual injection hose sections.|
|Step 5. Affixing installation boxes and routing of pressure hoses.||Step 5a. Further structure concreting and injection of leaking joints.|
|Step 6. Attaching PVC endings to the formwork and routing the injection hose.||Step 6a. Removal of caps from the PVC endings and screwing in of the lubrication fitting. Injection of leaky joints.|
Installation in a retaining wall lock
Fig. 1. Layout and attachment along lock contact surface.
Fig. 2. Installation of QUICKY joint and pressure hoses.
Fig. 3a. Layout of hoses above retaining wall lock.
Fig. 3b. Execution of styrofoam inlay in the bottom slab and routing of pressure hose endings.