New type of concrete ditch extrusion machine for civil engineering

ABOL/O/F/2003-007

Abstract

A French SME specialized in the design of equipment for civil engineering has developed and patented a new type of concrete ditch extrusion machine. It is characterized by an extension system, which allows the adjustment of the width of the supporting crawler and an extrusion mould guided by the bottom of the trench. It allows to reduce the quantity of raw materials used, the labour force but also to improve the deposition speed of concrete. The company seeks partners to licence its patent.

Description

The construction of roads and railway tracks requires building parallel concrete ditches which are used to collect and evacuate the rain and surface water. The building of such ditches is performed by first digging a trench using an excavator and then deposing concrete with a concave shape mould using a concrete extrusion machine. This machine is traditionally made of a crawler running along the trench and guided by a wire, which has beforehand been installed by a geometrician and a mould which is suspended over the trench. Recurrent problems with existing systems are :
- a lifting phenomenon of the mould during extrusion
- the sinkage of the machine on not enough stabilized soil causing troubles in the concrete deposition
- a limitation in the depth of descent of the mould due to the machine capacity and design.
With the new design proposed here, the mould can be lowered much lower than existing machines..

The present invention developed by this small French company allows the elimination of the wire guidance (thus the need for a wire installation step beforehand), as well as the mould lifting phenomenon. Indeed the mould in the proposed system is guided directly by the bottom of the trench as it lies at the bottom instead of being suspended over the trench as in existing systems. Moreover it can be lowered much lower to depth varying from 0,5 to 3 meters.

This function is made possible thanks to a specially designed mould and also through a crawler gauge extension system which thanks to 4 articulated arms allow to move the crawlers away from the centre of the vehicle. The crawler vehicle width can be thus quickly switched from 2,9 up to 7,5 meters while keeping the crawler vehicle compact enough when the arms are folded back. The extruding machine can be easily transported on the construction field without requiring to be disassembled or any further extending equipment. This varying width allows to lower the mould deeper into the trench and to better adapt to the shape of the construction field.

This machine allows the reduction of the quantity of concrete used, requires less personal to be set up and used, and also increases the speed of concrete extrusion.

The size of the crawler, its extension range can be further adapted to customers specific needs. The company wishes to licence its technology to civil engineering machines and vehicle manufacturers and to build a partnership with those to develop an innovative continuous concrete feeding system. This feeding system is currently at the design stage for a further improvement of the feeding speed of the extruding machine and thanks to a better performance a decrease of the operating costs.

Innovative Aspects
Extrusion mould guided by the bottom of the trench itself (no need for a parallel wire)
Extensible crawler with thanks to a 4 arm extension system thus allowing a deeper lowering of the mould and a better adaptation to the construction field.

Main Advantages
The extension system with 4 arms allows the possibility to increase the gauge while keeping a compact machine easy to transport and not requiring disassembly on site.
Elimination of the mould lifting phenomenon, fast installation
Optimisation of the quantity of concrete used, thus allowing a constant ditch thickness
Possibility to multiply by 5 the quantity of work and divide by 4 the quantity of personal (e.g. the machine can perform 400 m of ditch per 8-hour working day with 2 workers vs. 80 m manually with 8 workers with current existing machines).

Current Stage of Development

Available for demonstration A prototype has been built and delivered and is currently used on a TGV train construction site. A second model is currently being assembled.
 

Intellectual Property Rights

Patent(s) applied for but not yet granted (application filed on 30/06/2003).

Organisation/Company Type: Industry

Organisation/Company Size: ◄10