CONSTRUCTION SEGMENT – RESPONSIBILITY ON BUILDING SITES
The construction industry inevitably has an impact on the environment. In view of this, the challenge faced by all construction companies is to keep any such impact to a minimum. BAUER Spezialtiefbau GmbH operates an EMAS-certified environmental management system and submits itself to environmental auditing procedures. The companies in the Construction segment are also committed to collaborative, efficient working practices in the execution of their projects, which further helps to conserve resources.
The two affiliates of BAUER Spezialtiefbau GmbH – SCHACHTBAU NORDHAUSEN GmbH and SPESA Spezialbau und Sanierung GmbH – specialize in construction and related areas. Schachtbau's operations include infrastructure engineering, mining, and machinery and plant manufacture. In the environmental technology field, the company plans and constructs turnkey biogas plants, among others. Spesa specializes in the maintenance and restoration of historical monuments, the renovation of technical structures, and concrete remediation. It has to date worked on many highly interesting restoration projects.
In order to meet the demands of environmental sustainability, the relevant issues must be integrated into quotation and planning procedures well before construction work begins. Ecological considerations also play a key role in determining which methods and techniques are offered and ultimately deployed on specific projects – especially as ecologically sustainable projects can often also entail economic benefits, such as by reducing transport volumes. And across all our many projects worldwide, we ensure compliance with national environmental standards as a minimum.
Works in water protection and nature conservation areas are subject to special demands. In anchoring works, biodegradable anti-corrosion compounds (grease) can be used to treat the pre-stressing steel strands of removable anchors in order to prevent possible environmental pollution.
The most-used materials on our construction sites are steel and concrete. These materials are very durable, and so almost never have to be disposed of. In some construction engineering processes structural steel components are installed temporarily and removed again when the works are complete. They can then frequently be used on subsequent projects. Where disposal is necessary, steel is a very valuable raw material gained from the recycling process.
Some construction engineering processes employ flushing fluids to transport the soil to the surface. Special filtering and separation systems are used in such situations to treat the fluids so that they can be re-used or at least disposed of in an eco-friendly manner. Group subsidiary MAT Mischanlagentechnik GmbH has long-standing experience and know-how in the manufacture of mixing, conveying and separating plant.
TEST WINNER
Another key consideration in construction engineering operations is the efficient and environmentally sustainable transportation of equipment, construction materials and soil to and from the site. This demands detailed logistical planning. Employing construction techniques which use less material than others is a particularly effective means of reducing the number of trips and so cutting emissions which impact on the environment.
TWO EXAMPLES OF ECOLOGICALLY SUSTAINABLE FOUNDATION ENGINEERING
BAUER SILICATE GEL LWS
Silicate soft gel injection is among the most successful construction techniques employed by the BAUER Group worldwide. BAUER Spezialtiefbau GmbH has already installed more than 350,000 m2 of base seal with great success. In this process, encased excavation pits are provided with a horizontal barrier layer in order to prevent groundwater incursion. After precise mixing, the LWS solution is injected into pre-drilled or vibro-compacted grout casings.
In developing the BAUER silicate gel LWS, the company placed a new, much stronger focus on aspects of environmental compatibility and economical use of resources. As part of this approach, we paid particular attention to the issues of energy balance and CO2 reduction (see table). In a research partnership with the Freiberg Mining Academy, extensive testing was carried out in order to optimize the material composition and flow of the LWS solution.
The new BAUER silicate gel LWS is far superior to other base sealing techniques in terms of environmental sustainability, without losing out on robustness or reliability. As the grouting can be carried out round-the-clock, daily output rates are doubled, so greatly speeding up completion. The product has been patented, and has been approved by the competent construction supervisory authorities. Its environmental compatibility has also been affirmed by a number of tests carried out by independent organizations. It therefore more than meets the demands of sustainable foundation engineering.
THE MIXED-IN-PLACE (MIP) PROCESS
In recent years especially, dams and dykes on many rivers have proved to be no longer adequately sealed or stable in withstanding extreme flooding. In many cases, they had not been adequately serviced or upgraded as necessary for a long time, resulting in ruptures or undermining. Checks carried out as a result of these events revealed the urgent need to reinforce or provide additional sealing for the structures in question.
In the mixed-in-place process the existing soil is mixed together with a binding agent. A triple auger is used to break up the soil and work in the suspension. Overcutting the individual barrettes creates a retaining wall in the dam or dyke which prevents seepage through or flow beneath the structure. Bauer's engineers were able to call upon more than 20 years' experience in projects employing this technique.
The mixed-in-place process offers great benefits for the environment:
- Using the existing in-situ soil conserves resources
- The process is very eco-friendly, as it generates less noise and fewer emissions than other techniques.
- The closed suspension circuit means that no impurities of the dyke slopes occur.
- Transport volumes are much less than when installing a pile or diaphragm wall.