Reinforced concrete construction
Reinforced concrete is T H E all-purpose construction material of the 20th and 21stcentury, a compound material consisting of the two components of concrete and concrete steel. Concrete is the most important construction material in Germany – more than 100 cubic metres of concrete are used each year.
Construction with reinforced concrete uses concrete as a pressure-resistant material as well as usually concrete steel or tie rod for traction force absorption. In problem areas also reinforcing bars from stainless steel or glass-fibre reinforced plastic are used.
Concrete is a chemical instable construction material and has no unlimited life span.
Reasons are natural aging processes which take place over the course of time. By the influence of, for instance, water and air chemical processes within the concrete are induced; the so called carbonising or concrete corrosion begins. Especially reinforced concrete is endangered because reinforcing steel starts to corrode.
Concrete patching starts with the removal of damaged concrete and reinforced steel rust removal.
It is recommended to save the concrete constructions from impacts of harmful substances. Therefore paint coatings and access covers shall be used. Those protective measures for repaired concrete constructions go without saying.
Bridge floorings are subject to permanent attacks through precipitation, chlorides, road salts as well as changes between frost and thaw. Variations in temperature, congestion and associated dynamic loads can be also added as aggravating factors. Un-protected steel-reinforced concrete constructions may corrode very fast and be massively weakened.
Protection against all of named attacks is very important for bridges. Usual protection was not always efficient.
Epoxy resin sealing for bridges protect the constructions against attacks through humidity and therein dissolved pollutants, and form a smooth protective shield which is durably robust and elastic at the same time.
The full adhesion to the subsurface is protective against the ingress of water. A saved sheared coupling to the later applied asphalt is formed.
Crack pressing | Gel injection
The rehabilitation of small cracks is carried out by treatment of epoxy resin. Thereby a filling of cracks near the surface is carried out without pressure. Deeper cracks within concrete components are closed under high pressure by using an injection of liquid two-component resin.
Many objects cannot be repaired by a classical external and internal waterproofing or sealing. Convincing answers can be given by special gelling procedures, as a surface sealing of components in contact with the soil (vertical and horizontal) or as a partial waterproofing or sealing (in case of cracks, local separations, connections).
Different methods and materials are used for this work.
In praxis industrial floorings are exposed to different loads. All mechanical forces exert tensions within the structure and especially the directly used surface.
In praxis epoxy resin coatings have proved oneself in different branches (food, chemistry, automotive engineering) for many years.
Coatings are screeds from solvent-free epoxy resign which are applied with a depth of 0.5-2 mm. After hardening coatings are free from pores and do not leak. It is possible to color them with epoxy resin pastes in any way.
Impregnation is a treatment of absorbent surfaces like cement floor and concrete with a low viscosity, good penetrating epoxy resin solutions which partially fill the pores. By sealing the surface is hardened, resistivity is increased and dust formation by friction is prevented.
Concrete in Mills
Concrete is often installed in different ways in mills. There are mill buildings, silo cells, foundations, walls, covers made of concrete.
Silo cells are exposed to extreme weather like wind, sun, driving rain and large temperature fluctuations. As a result, there is more damage than other buildings. Inside the silos, large quantities of bulk materials flow along the walls, which strain the wall surfaces and grind them down over the years.
In addition, there are usually high drop heights and turnover rates, as well as coarse or chemically aggressive particles, which contribute to the aging process of the silo walls. Silo cell repair is always a solution tailored to local conditions, because the construction of the silo plants corresponds to the bulk material to be stored, and thus also has specific damage patterns.
In addition to the repair of the silo walls and ceilings, it is also important to design the outlets at the silo end in such a way that the best possible and uniform flow properties of the bulk material are achieved.