NL1044539A - Production method for industrial floor panels. - Google Patents

Abstract

The invention relates to a production method for optimally distributing a weighed quantity of earth-moist concrete in a mould for industrial floor slabs, whereby the earth-moist concrete is optimally filled and evenly distributed over the entire surface of the mould using a multifunctional funnel with a square outlet. This optimal filling results in no loss of valuable residual concrete, with minimal contamination of the production means due to the absence of scraping off excess concrete, optimal use of the materials in concrete recipes, optimal compaction and possibilities for applying profiles in the concrete for additional functions.

Description

Production method for industrial floor panels.

The invention relates to a production method for optimally distributing a weighed quantity of earth-moist concrete in a mould for industrial floor slabs.

A device for distributing concrete mix is known from the German patent DE4115268A1. With the aid of this device, concrete mix is supplied by a conveyor belt and distributed over a round plate to be poured by a mobile pouring bucket. The aim of this design is to be able to use a stiffer concrete mix than can be moved by a pump.

The purpose of the production method according to the invention is to distribute a weighed quantity of earth-moist concrete evenly along the edges and over the surface of the mould in a multifunctional funnel with a square outlet, so that an excess of earth-moist concrete mix does not have to be used.

Prefabricated industrial floor slabs are widely used in the Netherlands, partly due to the often unstable soil, in industry, agriculture and road construction, also because the slabs can be used elsewhere after use and thus meet modern requirements for reuse.

The load-bearing capacity of industrial floor slabs (usually with dimensions of 2 by 2 meters) depends on the subsoil and the functionality (load-bearing capacity and stability in horizontal direction) of the slab, such as thickness and the flexural strength of the concrete. The flexural strength depends on the materials used, such as sand, gravel and cement.

In large-scale production, industrial floor slabs are usually produced in moulds that run around a production line that has multiple positions and where the slab is often produced upside down. At each position, special processing takes place, such as placing reinforcement and hoisting equipment, applying a top layer, applying the concrete mix and compacting the concrete mix.

A concern in production is the filling and compaction of the concrete mix. In order to achieve high flexural strength, the hardened concrete must consist entirely of stone materials such as stone aggregates (of sand grains and gravel grains) and cement stone that encases the aggregates.

Insufficient compaction will result in air pockets in the hardened concrete, which will seriously affect the flexural tensile strength.

If the mortar contains more water than is necessary for the chemical hardening process, water pockets will remain in the hardened concrete, which will negatively affect the flexural tensile strength.

The amount of cement needed in the concrete mix depends on the grain structure of the mix. This structure must have an optimal grain distribution, from the smallest grain of sand to the largest grain of gravel. The larger the largest grain of gravel in the concrete mix, the less cement is needed to achieve the optimal flexural tensile strength.

There are various production methods, each of which requires care to achieve the highest possible flexural strength.

When using self-compacting concrete, an excess of cement is needed to prevent air pockets and to achieve sufficient flexural strength. Cement is expensive and a lot of CO is released during production.

When using liquid mortar, an excess of cement is required, because more water is used than is needed for the chemical hardening process. The flow properties guarantee good filling of the edges and corners. These plates have less load-bearing capacity at the same thickness. A greater thickness causes an increase in the cost price. With this production method, the plates are generally not turned upside down

(but with the top layer on top) produced and the plate remains in the mold during the curing process.

When using earth-moist concrete mix, an excess height is required when filling the mould because the corners and edges of the mould cannot be filled properly when applying the concrete mix. The earth-moist concrete mix contains exactly the right amount of water in the mixture for the chemical hardening process. After compaction by vibrating the mould (and/or using an overhead vibrator on the concrete mix), the excess of concrete must be removed after compaction. This excess is scraped away. This residual concrete is, due to the compaction process that has been undergone, no longer usable for production. Concrete mix is lost, including loss of valuable cement.

The scraping process causes contamination of the mold and production track, which must be cleaned from time to time, resulting in lost production time.

The scraping process pulls out oversized gravel grains from the compacted concrete. This limits the diameter of the largest gravel fraction. The larger the largest gravel fraction, the less cement is needed to achieve the optimum flexural strength and the lower the material costs.

A characteristic of the production method according to the invention is that, due to the absence of scraping (or otherwise removing the compacted excess mortar), the largest gravel grains in the mixture can be relatively large, which means that less cement is required in the mixture.

When producing with earth-moist concrete mix and dosing the concrete mix in the mould in such a way that no excess height is created after compaction, the concrete mix is usually compacted by vibrating the mould and/or vibrating the top surface of the concrete mix. The displacement of the concrete mix by vibration is limited. In order to ensure some displacement (especially in the corners and edges of the slab), an extra long vibration time is required, which is at the expense of the capacity of the production line and the possible occurrence of segregation at other locations.

Characteristic of the production method according to the invention is that it offers the possibility of compacting with (a matrix of, for example, 9 or 16 fixed or slightly movable) rammers, which, due to their force, ensure additional distribution of the concrete mix, so that the corners and edges of the industrial floor slab are better filled.

When using earth-moist concrete, filling the mould with concrete mix is usually a continuous process in which concrete mix is spread over the full width of the mould. More concrete is added to the mould than is necessary to obtain the required slab thickness after compaction.

Characteristic of the production method according to the invention is that the distribution of the concrete mix takes place by means of a filling funnel that moves in place and in height and which, if desired, remains in one place for a longer period at the corners and edges of the plate and, if desired, doses concrete mix at an adjustable height in such a way that after compaction those places are completely filled with concrete mix and in such a way that no extra time is required during compaction to move concrete mix by vibration.

Industrial floor slabs are usually laid on an optimally compacted sand bed, from which the slab derives its load-bearing capacity.

The underside of the slab is, due to the oversize and the current scraping process, flat. The stability against horizontal displacements of the slab (for example by braking of a vehicle driving over it) is largely derived from the good filling of the joints between the industrial floor slabs.

Characteristic of the production method of industrial floor slabs according to the invention is that when compacting the concrete mix, a profile can be applied to the underside of the slab with the top compactor(s) of the compaction station, which provides the slab with extra resistance when the slab is horizontally loaded, for example by a braking lorry. 5 The production method according to the invention will be explained in more detail below with reference to figure 1.

According to the production method, a weighed quantity of earth-moist concrete mix, with the same consistency, is dosed into a height-adjustable, multifunctional funnel 1 with a rectangular outlet 2 that can move horizontally in two directions above the mould.

When filling the mould, the edges of the mould are filled in a continuous flow from a corner of the mould 3 as a starting point, after which the funnel makes a final stroke from the outside to the inside towards the centre of the mould. This can take place in a division of, for example, 9, 16 or 25 imaginary compartments. When filling the mould, a slope 4 will be created that will slope down in particular towards the part of the mould that has not yet been filled. The edges of the mould are optimally filled with the earth-moist concrete mix 5. While moving the funnel, from corner to corner, the mould fills along the edges to the desired height. With the final stroke towards the centre of the mould, the rest of the concrete mix is brought to the centre of the plate. The funnel moves upwards, after which the optimally filled mould is transported to the next position for further processing.

Claims (7)

CONCLUSIONS 1 Production method for concrete prefabricated industrial floor slabs, usually with dimensions of 2 by 2 meters, which are produced on a production line with multiple stations, where an operation can take place at each station, whereby the shaping of the floor slabs takes place at a specific station, with the top of the floor slabs (upside down) on a steel mould, characterised in that the dosing of the moist concrete mix there in or on the mould takes place so accurately, so homogeneously and with such a smooth top surface and so exactly at height that the removal of the excess height and excess of moist concrete mix, with all its associated disadvantages, is unnecessary. 2 Production method for concrete prefabricated industrial floor slabs according to claim 1, characterised in that the dosing of the quantity of earth-moist concrete mix required for a single slab takes place at a separate dosing station outside, above or next to the production line, whereby the concrete mix is transported to the filling station above the production line. 3 Production method for concrete prefabricated industrial floor slabs according to claim 1 and/or 2, characterised in that the filling and distribution of the concrete mix in the mould takes place with a multifunctional filling funnel, which has a relatively small opening at the bottom, with a horizontal termination at the bottom, which moves in a fixed pattern and horizontally, from corner to corner and then over the rest of the upper surface of the mould when filling it, thereby completely filling the mould up to the bottom of the filling funnel. 4 Production method for concrete prefabricated industrial floor slabs according to claim 1, 2 and/or 3, characterised in that the filling and distribution of the concrete mix is carried out in several layers, in that the filling funnel, after the procedure of supplying the concrete mix, filling the funnel and distributing it over the surface of the mould is repeated in such a way that after the last cycle the filling funnel is completely emptied and can be moved vertically so that the mould can move unhindered to the next station. 5 Production method for concrete prefabricated industrial floor slabs according to claim 1, 2, 3 and/or 4, characterised in that during the filling process, whether or not after the application and filling of each layer of concrete mix or at the end of the filling procedure, the concrete mix in the mould is compacted with mould vibrators, generally at the bottom of the mould. 6 Production method for concrete prefabricated industrial floor slabs according to claim 1, 2, 3, 4 and/or 5, characterised in that in the station following the filling station of the production line, the concrete mix can, if desired, be compacted with a vibrating device on top of the concrete mix. 7 Production method for concrete prefabricated industrial floor slabs according to claim 1, 2, 3, 4, 5 and/or 6, characterised in that by profiling a vibrating plate, additional functions can be added to the concrete slab, such as ensuring better transfer of the forces exerted on the industrial floor slab by, among other things, vehicles.