Geopolymers

Comparison of concrete works and URETEK technology. Pros and cons

Causes of deformation in building foundation

Formerly, foundation was repaired by cementing, now a new solution is used – URETEK technology. It represents a rapid and secure alternative to concreting and piling of foundation. URETEK technology deploys unique strengthening methods for foundation repairs, somewhat similar to advanced surgery. This technology allows eliminating the reasons for structural subsidence and deformation by re-levelling slab covering of concrete foundations, strip foundations, pile foundations and floor slabs and even solving problems related with access roads.

Work process

URETEK resin is inserted in the soil under a structure through small holes (usually with diameter of 16 mm, only 12 mm in case of interior works).

Then URETEK resins expand, filling cavities, compacting subsoil and stabilising the foundation (or other load-bearing structures), thus allowing re-levelling of the house.

For optimum results and safety purposes, the pressure generated in the course of expansion is constantly checked with laser equipment.

Cracks in the walls usually shrink. However, in case of brick wall, it only requires secondary treatment of joints with mixture or joining with special fixture, patching and painting of cracks in case of plastered walls.
Windows and doors will usually function normally again.
Gaps between floor slats and fixed floors generally disappear as well.

Guarantee

Materials used comply with strict ecological and safety requirements and have been designed specifically to resist drying and subsidence. Quality is guaranteed for more than 50 years.

Strengthening methods using concrete works

Over many years, concrete works have been used as a classical method for foundation repairs. Compared to traditional concrete works, the advantages of URETEK technology include speed, cleanness, durability and predictability, economic efficiency and an opportunity to avoid interfering with normal use of the structure.

URETEK material ensures durable soil stabilisation and building re-levelling faster than concrete works, where nothing can be guaranteed. Now it is possible to heave a house to desired height within a day or two, or a couple of weeks, depending on its construction technology. Furthermore, resin injection does not generate waste, there is no need for excavation works, water, cement or concrete.

It is important to mention that injection works do not require vacating entire room. Unlike concrete works that need lots of preparation and interior works, URETEK technology does not need any of that. Small holes (diameter of 12–14 mm) can be drilled between cover plates and even through carpeting and there is usually no need for moving the furniture.

URETEK method is ideal for foundation repairs even in case of clay and other porous soils, as it solves subsidence problems. The method ensures load-bearing capacity of substrate and uniform properties of load-bearing layers.

In the course of concrete works, it is necessary to improve poor soil conditions, such as unbound, dusty and wet substrate or substrate containing poorly compacted filling material. This is due to the reason that extra weight of concrete may further aggravate the situation.

Cost of concrete works

Besides being more convenient, safer and durable, URETEK injection solution is usually also cheaper than traditional concrete base.

The cost of concrete works depends on many factors, including:

Location of building,
Actual cause of the problem,
Properties and condition of the soil under a structure,
Type and profile of building foundation,
Surroundings, e.g. access to the plot, adjacent buildings and support walls,
Unknown, unpredictable condition of the soil under a structure,
Quantity of required material,
Time spent on work.

If only one corner of the house requires re-levelling, concrete base may be cheaper, but it may still lead to further problems over time. For instance, new cracks may develop in the house if concreting is performed in only one section of the foundation, not to mention additional load on the base affecting the substrate that was used to former loads.

In most cases, resin injection is cheaper than other methods, including concreting of foundation.

Keywords

Restoration of historical monuments

Sites of great historical and cultural value are threatened by natural ageing and going to ruin just like any other structure.

Sites belonging to national and global cultural heritage must be restored or reconstructed to keep structural damage to minimum, be it then repair of walls and floor or lifting and strengthening of foundation. Damage of historical buildings can be minimised by using URETEK geopolymers technology.

Manor buildings and palaces, castles and fortresses, churches and temples, but also many other sites of historical interest age, break down and go to ruin. Condition of walls, roofs and ceilings of the building is affected by constantly alternating external factors: pressure, temperature, humidity and airborne gases.

Equally dangerous are changes in soil on which the site of historical interest has been erected. Thus, weakening of soil under the structure may cause subsidence of ground floor and reduce stability of foundation, which leads to damaging other structural elements of the structure.

Complications related to strengthening soil

Subsidence of foundation and floor of sites of historical interest often causes occurrence of cracks in floor and walls. In that case, simple cosmetic repairs of walls and floor are not enough to improve the situation, because the cause of cracking is not eliminated. Without improving the condition of substrate and lifting foundation or floor, the situation continues to worsen and may ultimately result in complete destruction of architectural monument.

Although sites of historical and cultural interest are generally renovated by using state-of-art technologies and building materials, lifting of floors and strengthening of foundation in these structures is often performed using traditional methods. However, traditional technology along with involvement of heavy machinery and concrete and earthworks may damage the site of historical or cultural interest.

Elimination of cracks in the floor and walls of an architectural monument, as well as strengthening of substrate and lifting of foundation or floor is much more efficient when using URETEK geopolymer resins injection technology. That technology makes it possible to perform works without affecting the historical and cultural value of the site and also reduces the budget for repair and restoration procedures.

Provided technology

There are two URETEK geopolymers injection methods that can be used for strengthening the soil under historical monument and eliminating floor and foundation subsidence – Deep Injection and Slab Lifting. In the first case, geopolymer material intended for strengthening the soil and lifting the foundation is inserted deep into the soil under the structure, in the second case geopolymer is inserted immediately under ground floor.

Geopolymers are injected in soil or under the floor through special pipes with diameter of 12–16 mm, inserted in holes drilled in ground floor or soil around the perimeter of the building. Borehole diameter may be 12–32 mm. No other interventions are required on the site. The equipment for injecting geopolymer resins is compact and mobile. Using it has no effect on the historical or cultural value of the site. Injection holes can be easily eliminated later on.

All procedures performed with URETEK geopolymer resins, be it then strengthening of soil, securing or lifting foundation or floor, do not take long. After injection, geopolymer material expands, filling all cavities in soil and hardens within just 15 minutes, exerting vertical pressure. Lifting of foundation and floor is monitored in real time by using laser level.

Keywords

Huge impact of extreme weather events on the foundation and the soil under the structure

Extreme weather events, natural disasters, long periods of drought, rain and cold have strong effect on the soil under the structures and on the foundation.

The summer of 2018 was extraordinarily warm, and the heat lasted for a long time. At the same time, January was one of the coldest in history. While some people were exhausted from record high temperatures, other regions suffered from flooding. Rainstorms and cyclones had a devastating effect on many buildings and population in general.

How weather phenomena affect soil

Soil types vary by properties and their response to weather conditions, and they may have serious impact on load-bearing structures of buildings. Houses built on loose soil, sand and reactive clays (rising soils) may suffer the most due to seasonal or extreme rainfall, floods and drought (or cold).

Reactive clay expands when exposed to moisture and shrinks when drying. This is accompanied by soil splitting during long periods of drought and expansion during humid periods. Clay loses its porous structure as a result of freezing and expansion in cold weather.

Sand and loamy soils tend to subside due to rainfall, because water flushes off small particles and larger particles sink.

Filling material used in construction often consists of soil, but also other materials, such as brick or concrete fragments, also crushed construction materials. When water finds its way through such material and flushes away minor particles, it may cause the soil to sink. The effect of the process can be visually depicted as recess in the ground, whereas it may further deepen due to poor soil compaction and general condition of surrounding soil. In case of changes in the condition of soil under a structure, it can no longer support the foundation and the structures gradually start to sink. Building sinks either partially or entirely, but in any case, unevenly. This is called soil subsidence.

Another important factor is humidity level of the soil. For instance, clay soils in a region with moderate temperature are humid in general. But due to lasting dry weather, soil loses humidity and shrinks, causing the soil to sink. At the same time, such soil absorbs lots of water in rainy season or becomes impermeable. Along with freezing or (subsequent) melting, the soil may also cause risk of subsidence. In the event of a flood or broken utility line, water may carry away or scatter the soil, resulting in erosion and subsidence. All that can cause serious damage to the foundation and load-bearing structures of buildings and special structures.

Extreme climate conditions have become more frequent all over the world. For example, summer with record-breaking high temperatures affected the foundations of many buildings even in regions with mild marine climate (Great Britain). Continuous warm temperatures caused the surface water to dry out, which in turn caused subsidence of buildings. Therefore, insurance companies received from house owners exceptionally many complaints and claims regarding buildings subsidence.

How to combat soil subsidence

Fortunately, there are methods that allow quick, effective and sustainable protection against soil subsidence. Innovative solutions offer an alternative to traditional invasive and labour-intensive methods that use concreting of foundation or piles.

Patented URETEK resin injection technology does not require troublesome excavation works or cause major discomfort, because residents can often continue to live in the house while the works are performed.

Keep in mind that in case of discovering signs of subsidence you should immediately consult with specialists-designers or engineers-geotechnicians and obtain information and facts necessary for choosing appropriate solution.

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Resistance to cracking of reinforced concrete structures

Resistance to cracking is definitely observed when studying the durability of reinforced concrete structures. Builders can ascertain the resistance of the studied material to various internal and external factors. This indicator is expressed by the amount of time until the occurrence of first cracks. The longer the period when the structure remains intact, the greater the resistance of material to cracking. Crack develops when the stress factor significantly exceeds material’s permitted threshold value.

Accurate estimation can be obtained only by expert assessment of concrete samples. That currently most efficient method of study predicts future durability of the structure.

Factors affecting resistance of concrete to cracking

Occurrence and progression of minor defects in concrete can be induced by external factors – humidity and temperature – as well as the properties of the material itself. Determination of resistance to cracking takes into account information regarding the quality, flexibility, creep, settling and other properties of the material. Important factors include structural form and dimensions of the building.

Furthermore, the technology of manufacturing the cement must be considered. Materials with low hardening speed develop cracks less frequently cracking. That is why determination of resistance to cracking is a rather complex process and requires versatile analysis.

Options for increasing resistance of concrete to cracking

Even the appearance of small cracks in concrete structures is considered rather dangerous. Minor damages may cause cement to chip off, leaving the fixture exposed. This leads to corrosion, which causes further degradation. Concrete can be made more durable by using the following methods:

– using additives with special strengthening properties;
– magnetisation of water;
– inspecting the composition of concrete;
– covering the surface with iron;
– installing a special protective layer to avoid occurrence of small cracks;
– creating concrete with the best possible structure for particular purpose.

Optimum concrete composition requires using correct ratio of chosen components, which makes the concrete structure more durable.

If the crack has already occurred

Prior to repairing concrete structures, it is important to ascertain the cause of cracks. Restoration works can be divided in two:

– repair of structural defects;
– erection of new structures to replace the damaged parts.

Injection method represents optimum way of removing cracks. Special mixture is inserted in the problem area by using pressure. Where it is necessary to restore protective layer, shotcreting method is used. In that case a special construction mixture is prepared, which is then applied to prepared surface under pressure.

If the defects occur due to the soil, the problem needs to be solved urgently by strengthening or stabilising the subsoil.

URETEK specialists have everything they need to analyse, repair and restore concrete structures. When you contact us for help, every client may consider all their problems solved.

Comparison of concrete works and URETEK technology. Pros and cons

Causes of deformation in building foundation

Work process

Guarantee

Strengthening methods using concrete works

Cost of concrete works

Keywords

Restoration of historical monuments

Sites of great historical and cultural value are threatened by natural ageing and going to ruin just like any other structure.

Complications related to strengthening soil

Provided technology

Keywords

Huge impact of extreme weather events on the foundation and the soil under the structure

How weather phenomena affect soil

How to combat soil subsidence

Keywords

Resistance to cracking of reinforced concrete structures

Factors affecting resistance of concrete to cracking

Options for increasing resistance of concrete to cracking

If the crack has already occurred

Keywords

Re-levelling and stabilizing the soil of a subsided monument

Keywords

Soil compaction and foundation stabilization of Mooste grain dryer

Keywords

Foundation strengthening and soil stabilization of the historic tavern building in Haapsalu

Keywords

Lifting of concrete slabs and soil compaction at Alavere silage storage facility

Keywords

Relevelling of the FEB warehouse concrete floors and soil stabilization

Keywords