Building and Construction

Construction industry offers wide range of application options for composites

hausbau.jpgBe it GFRP or CFRP, the construction industry is one of the most important fields of application for composites. One reason can be found in the diverse range of applications. Whether it’s profiles or pipes, cable ducts or light wells, formwork or bridge parts: composites are used in a variety of structural components. Taking place from 6 to 8 November in Stuttgart, COMPOSITES EUROPE will show how they can be deployed. Supplementing the exhibitors’ offerings will be a comprehensive programme with guided tours to the appropriate exhibitors and different lectures.

Though light in weight, composites have excellent mechanical strength, and they’re resistant to corrosion and fatigue, have low thermal conductivity and allow for great design freedom. Most of the time, moreover, large amounts of material are needed, simply because of the quantity required, on the one hand, and the size and/or volume of the components, on the other. On Wednesday at the trade fair, COMPOSITES EUROPE will present the factors that must be taken into account when using composites in the construction industry, the issues and requirements the industry is currently thinking about, and the providers who are already successfully engaged in the construction sector. On 7 November, experts will address these and other topics in lectures at the Composites Forum as well as at the Lightweight Technologies Forum. In addition, a guided tour will take interested visitors to the stands of various exhibitors from this segment.

A third of total GFRP production goes to construction

One third of the volume of GFRP produced in Europe last year went to the construction industry, according to the “Composites Market Report 2017”. The industry purchased about 380,000 tonnes out of a total of 1,118,000 tonnes. The figure from the year before was 373,000 tonnes. That means the user industry’s market share remained stable and matched the level of previous years. According to the study, the great importance of GFRP manufacturing for the economy as a whole is one reason why it tends to parallel the trajectory of the GDP in the long run. A boom in the construction sector directly impacts suppliers and thus the industry overall. In addition, GFRP components are already well established as a construction material in certain areas.

The importance of CFRP-based fibre-reinforced composites for the construction sector is significantly lower, but their growth prospects are much better. The construction industry purchased about 6,000 tonnes, or about 5 per cent of the total global quantity produced in 2017 of nearly 127,000 tonnes. However, experts forecast – very cautiously – that demand will double to 12,000 tonnes by 2022. The construction sector with its comparatively huge quantities and immense requirements stands out for the tremendous amount of potential applications it offers. However, the fact that the material is preferred in several fields even now shows that the conservative assessment presented here will be far exceeded.

Lightweight construction steadily gaining in significance

Coordinated by the Fraunhofer Institute for Systems and Innovation Research and published by Leichtbau BW GmbH, the study “Leichtbau – Trends und Zukunftsmärkte” [1](Lightweight Construction – Trends and Future Markets) also highlighted these excellent future prospects. The authors examined publications and patent applications for their lightweight-construction relevance. Because of its relevance, they looked at the construction sector as an additional user market. Long-term developments and trends are emerging, particularly for fibre-reinforced plastics and reinforced concrete as well as for various hybrid materials.

Looking at long-term trends, topics such as fatigue strength, mechanical properties such as pressure and impact resistance, load-bearing and bonding strength, density, economic viability, and thermal conductivity are joining weight reduction as factors associated with lightweight construction. Besides thermal conductivity (insulation), composite materials are mentioned particularly frequently in this context. When it comes to close-to-market medium-term developments such as patents, a content analysis similarly shows that an astonishing amount of plastics and composites are being developed as compared to metal-based lightweight construction materials. The expert report came to the conclusion that lightweight materials will play an even greater role in the construction sector, especially in the long run.

This assessment was shared by the authors of a report published by the VDI Centre for Resource Efficiency titled “Bestandsaufnahme Leichtbau in Deutschland”[2] (Taking Stock of Lightweight Construction in Germany). They found that lightweight materials play an important role in the construction sector and expect their use to increase in coming years. Among other areas, lightweight construction principles are applied in new designs such as facade constructions. Furthermore, it is becoming apparent that the use of FRP, in particular GFRP, will increase.

Legal framework prevents GFRP bridges

New application possibilities for composites in construction frequently fail because of legal framework conditions. Take bridge building, for example, where, depending on the country, permitting requirements or a lack of standardisation prevent the “serial use” of composites. Intensive efforts to develop GFRP bridges are currently underway in the US, Japan, Switzerland and the Netherlands, in particular. While GFRP bridges are now part of the standard repertoire in the Netherlands, they’re still the exception in Germany, according to the “Composites Market Report 2017”.

Using GFRP for bridges and roadways offers numerous benefits, experts say, because the material is immune to both frost damage and de-icing salts. Another benefit is significantly reduced weight. According to Carbon Composites e.V., a plastic bridge has only about 40 per cent of the weight of a steel composite and less than 30 percent of that of a prestressed concrete bridge. Plus, it can be prefabricated in significantly larger dimensions and lifted into position by crane. For starters at least, the road and traffic management office of the German federal state of Hessen began testing GFRP in a pilot project in 2008. A one-lane road bridge of 22 metres in length traverses federal highway B 455 near the town of Friedberg.

Construction with 20 percent market share in continuous processes

Bridges, however, aren’t the only exciting fields of application for GFRP structures. For example, light wells, cable ducts and manhole covers are also manufactured from the material using compression (SMC) or injection moulding (BMC) processes. Open processes are used for the production of facade elements. With continuous processes, too, the construction industry is a key buyer with a market share of about 20 per cent. Examples include pultruded GFRP profiles, which are growing at a strong 6 per cent clip in Europe right now, according to the “Composites Market Report 2017”. Interesting applications in this area include window profiles, reinforcing bars, carrier or cable duct systems, railings, and steps. GFRP pipes and tanks produced by spinning or winding processes are also relevant for plant and pipeline construction and for the oil and gas and chemical industries.

The construction industry offers promising application areas for CFRP, as well. For instance, CFRP strips are glued to concrete surfaces to strengthen buildings. According to Carbon Composites e.V., such corrosion-resistant reinforcements have already been used thousands of times worldwide to renovate objects or get them ready for new tasks. Reinforcing buildings via CFRP strips in this way offers significant advantages in terms of economic viability, ease of processing and optical appearance. They increase the tensile, compressive and flexural strength of load-bearing components, with only marginal changes to construction dimensions and weight. By now, the method is used not only for reinforced concrete but also for wood.

[1] “Leichtbau – Trends und Zukunftsmärkte”by Leichtbau BW GmbH (published in 2014)

[2] “Bestandsaufnahme Leichtbau in Deutschland” by VDI Centre for Resource Efficiency (published in 2015)