Job Report Soil Stabilization. Soil stabilization with Streumaster and Wirtgen technologies

Transcription

1 Job Report Soil Stabilization Soil stabilization with Streumaster and Wirtgen technologies

2 Wirtgen soil stabilization: High quality and precision: Applications in soil stabilization with Streumaster and Wirtgen technologies Soil stabilization with lime and cement is a tried and tested method which has been known for several decades. The process proved to be both highly beneficial to the environment and extremely cost-effective, and has therefore scored considerable success in recent years. The demands placed on both the quality of the work and the precision and reliability of the binding agent spreaders themselves have also increased greatly at the same time. Wirtgen and Streumaster have been developing efficient technologies in this product segment for many years. The two companies have brought their know-how together in a system partnership, which has resulted in a portfolio of technically mature binding agent spreaders that are perfectly adapted to the requirements of soil stabilization. The range of spreaders manufactured exclusively for Wirtgen includes: Single-axle or tandem-axle towed spreaders (model code TA or TC) Built-up spreaders (model code MC) for mounting on a carrier vehicle Self-propelled spreaders including carrier vehicle (model code SC) The different spreader models are available with different container capacities and different systems for applying the binding agents so that customers can always choose just the right technology for their type of project. The following field examples demonstrate that Streumaster spreaders offer their users an exceptionally high degree of precision, economic efficiency and successful operation. Soil stabilization is gentle on environment and climate Soil stabilization with lime, cement or other binding agents is not only a fast-paced and highly efficient method but offers a high degree of environmental friendliness and economic efficiency as well. Why? Because soil stabilization dispenses with soil exchange and soil disposal, thus saving large sums of fuel and labour cost for truck transports. All that needs to be done instead of disposing of huge volumes of used soil, excavating the new soil elsewhere, transporting and spreading it is to transport a few tons of binding agent to the construction site and mix it into the existing soil. In other words: Soil stabilization avoids the generation not only of tremendous amounts of CO2 but also of all other climatedamaging exhaust gas components. Soil stabilization is an environmentally friendly method because it dispenses with truck transports and thus exhaust emissions right from the start.

3 Germany: Stabilizing the base layer of a heavily trafficked motorway SW 16 MC and WR 2400 As part of the rehabilitation of the A99 motorway in the area of Munich s ring road, which is one of the most heavily trafficked motorways in Germany, the asphalt surface and part of the hydraulically bound base layer were milled off across a total width of 19 m and over a length of just under 2.5 km. The remaining 10 cm of the hydraulically bound base layer and the upper 10 cm of the underlying frost blanket were then recycled to a new base layer using the mixed-in-place method. Contractor SAT Straßensanierung GmbH completed this project using their Wirtgen soil stabilizer type WR The precise distribution of 20 kg of cement per square metre was ensured by an SW 16 MC binding agent spreader from Streumaster. This spreader model, a built-up unit for 3-axle and 4-axle vehicles and suitable for mounting on any type of chassis, has a container capacity of 16.5 m 3. The C in the model code signifies that this unit is equipped with a rotary feeder which can be used for both lime and cement. The application and distribution of the binding agent is governed electronically in proportion to the travel speed of the carrier vehicle. With a deviation of less than 5% in both longitudinal and transverse direction, the spreader s precision impresses the recycling and stabilizing pros. The binding agent spreader from Streumaster is the best you can get, as is the Wirtgen WR 2400 stabilizer. The two machines are an ideal match in terms of working width and spreading quantity, so that work can progress quickly and without any interruptions, says site manager Alexander Axt from SAT, full of praise for his stabilizing equipment. And that s no surprise, for the spreader s on-board hydraulic system guarantees an optimal response of the hydraulic valves and motors, and the electronically controlled proportioning valves enable the consistent application of binding agents even at varying The time frame for construction of the hydraulically bound base layer was extremely tight. Reliable technology enabled the SAT team to keep right on schedule. The SW 16 MC and WR 2400 needed no more than 32 working hours to complete stabilization of the total area of 42,000 m 2. 2// 3

4 travel speeds. The spreader s control system makes it possible to produce a very homogeneous hydraulic base layer that achieves the specified strength within a very short period of time, states site manager Axt, describing one of the most important quality criteria for paving a hydraulically bound base layer. The same degree of accuracy characterizes the WR 2400, by the way, when adding water to the stabilizing process. Working as a team, both machines thus create a durable basis for highly stressed major arterial roads. The SW 16 MC is operated via a panel with large screen and easily readable display. The spreader driver describes his state-of-the-art working equipment as follows: I very much like the machine s operation and logic. Via the camera installed at the rear, I can always monitor the spreading result so that I m sure to deliver a 100% work result. Loading from the tanker is carried out quickly, generating no dust at all. An indicator informs the driver when the container content has fallen below a critical level, enabling him to order new binding agent in good time. Yet another advantage is the spreader s enormous container capacity: Full tankers can be completely emptied in just two filling operations. Waiting times for the drivers of the binding agent suppliers are thus usually kept to less than one hour, which in turn has a positive effect on costs.

5 France: Stabilizing the subgrade for an arterial road SW 16 SC with Crocodile carrier and WR 2400 A subgrade of poor bearing capacity, interspersed with lumps of silicate rock, needed to be processed in Normandy for the construction of a bypass road. French contractor Guintoli completed this job using a very versatile team the SW 16 SC Crocodile binding agent spreader from Streumaster and the Wirtgen WR 2400 soil stabilizer. In this project, the all-wheel driven Crocodile from Streumaster gave an impressive demonstration of its performance capacity. The specified bearing capacity was achieved by precise metering of the binding agent to be added a mixture of lime and a special additive. The addition of lime further improves the material s plasticity, making the soil less susceptible to water while improving its compactability at the same time. The WeighTronic contributed significantly to the overall economic efficiency of the project. This metering control system from Streumaster precisely meters the binding agent to be spread, thus ensuring that the quantities are neither too large nor too small. It makes sure on the one hand that the soil properties specified by the clients are safely met, while the highly precise application rates permit highly accurate cost calculations on the other. Samples taken from the stabilized soil confirmed that the metering system worked precisely even at varying travel speeds. The Guintoli crew is full of praise for the modern, off-road spreaders: Our Crocodile is operated conveniently via the on-board computer in the driver s cab. All operating and spreading parameters are indicated on a large screen. What s more, the manoeuvrable carrier vehicle can be handled extremely easily even on bumpy ground. Following right behind the spreader, a WR 2400 soil stabilizer from Wirtgen completed two work steps in just one operation: It mixed the binding agent into the existing soil at a working depth of 35 cm while homogenizing the soil in the same machine pass. The resulting mix was of a homogeneous consistency and suitable for compaction to the required specification. One million cubic metres of soil needed to be stabilized for the construction of a bypass road. The SW 16 SC with the Crocodile off-road carrier vehicle was the ideal choice for precise pre-spreading of the special binding agent on the basis of lime. The binding agent container has a capacity of 16.5 m 3. Being a perfect complement to the SW 16 SC, the Wirtgen WR 2400 stabilizer completed the following two work steps in the processing operation in one single working pass. 4// 5

6 Germany: Soil stabilization as preparation for the construction of a production facility SW 10 TA and WS 2500 It goes without saying that Wirtgen relied on their own technologies when building their new production facility for special machinery: A towed spreader type SW 10 TA and a Wirtgen WS 2500 tractor-towed stabilizer were used for stabilizing the terrain of around 80,000 m 2 in size. The two units are perfectly compatible team players which is obvious after a quick glance at their technical specifications: The SW 10 TA has a spreading width of 2.50 m, which precisely matches the working width of the WS The soil in Windhagen needed to be improved by adding 20 kg/m 2 of a lime-cement mixture to achieve the required bearing capacity. The spreader s continuously adjustable screw enabled the quantity to be adjusted quickly and easily. While the hydraulically driven special spreading screw of the SW 10 TA applied the binding agent at a high spreading rate, the WS 2500 followed right behind, mixing the material into the soil at a depth of 40 cm. Many useful details make the spreader extremely uncomplicated to work with, says project manager Ewald von Schönebeck. As an example, a filling level indicator alerts the operator in the driver s cab when the filling level is low, thus giving him sufficient time to organize fresh supplies before the container is empty. One connector each for pneumatic filling on both sides of the spreader offers the flexibility needed for refilling of the binding agent. In everyday operation on the construction site, the heavyduty design with extremely low maintenance requirements adds to the high availability and productivity of the towed Streumaster spreader. Another clear asset is the unit s remote control feature: It is simply placed inside the driver s cab of the tractor vehicle, enabling the operator to conveniently adjust the slide gate or to switch the spreading unit on or off. Practical functions like these make work easier for us and ensure the continuous and thus economical completion of the project, says von Schönebeck, summing up his good experience of working with the Streumaster machines. Creating the foundation for maximum load-bearing capacity: Special machinery weighing in excess of 100 tons will soon be produced where the SW 10 TA towed spreader is now evenly distributing the lime-cement mixture.

7 A dust protection cloth made of special fabric rubber minimizes dust development during the spreading operation. Soil stabilization Soil stabilization with lime and cement converts untreated soils, which are usually averse to compaction, into material of permanent water resistance, frost resistance and volume stability, as well as increased compressive, tensile and shear strengths. The mixing operation triggers an immediate chemical reaction between the water contained in the soil and the binding agents, which removes humidity from the soil. This results in an immediate improvement of the material s plasticity, compactability and bearing capacity. The whole operation is extremely simple: In a first step, binding agent spreaders from Streumaster spread the specified quantity of the binding agent to be added evenly on the ground. The construction materials are then homogeneously mixed into the soil by Wirtgen soil stabilizers. Final compaction by single-drum compactors additionally optimizes the soil properties. This method is particularly suitable for: the production of foundation layers for roads of all construction classes in road and path construction, the production of homogenized soils serving as backfill, the construction of dams, embankment walls and site access roads, subsoil improvement in road and path construction, as well as the development of industrial sites and estates, the processing of soils averse to treatment for subsequent soil consolidation, the production of replacement material in the fill-in area of mains supply networks. 6// 7

8 Illustrations are non-binding and may include customized fittings. Subject to technical changes. Performance data depend on operational conditions. No EN-10/08 by Wirtgen GmbH Printed in Germany Wirtgen GmbH Reinhard-Wirtgen-Strasse Windhagen Germany Phone: +49 (0) / Fax: +49 (0) / Internet: info@wirtgen.com