LWAgeolight is an internordic project aiming at developing technical solutions for the use of LWA for insulation and lightweight fill in roads and railways.
The project had focused on the following topics: LWA in combination with geosyntehtic reinforcement, LLP-Light Loadspreading plate, mechanically stabilised LWA, surface icing, required material properties and test methods for LWA, publication of results and implementation of results at European level through CEN.
LWAgeolight includes laboratory testing, numerical analyses, model tests and field tests. Thermal, physical and mechanical properties of different types of LWA are determined as basis for design and product control purposes.
- The project has proved that LWA with mechanical stabilisation (compaction) can be used as light weight fill and insulation material in roads and railways. The compaction typically will result in a volume reduction of 10-12 % with a corresponding increase in unit weight compared to loose state. Compacted LWA has high stiffness and resistance to permanent deformations provided the stress level is not causing crushing of the grains.
- LWAgeolight has verified that LWA in combination with geosynthetic reinforcement increases the stability of the reinforcement will increase the resistance to plastic deformations (e.g rutting). Reinforcement on top of the LWA should be of a grid type where the aperture size is correlated with the grain size of the granular material.
- The LLP method has proven to provide beneficial effects to level out deformations and settlements e.g. in connection with bridge abutments. Different types of light aggregate concrete (LAC) can be used for the LLP which can result in a density varying from 520-1310 kg/m 3 . The results from the project verify that dependent on the type of LAC and the layout of the plate the LLP can have a capacity for bending moment varying from about 50-150 kNm/m and a shear force capacity varying from 30 to more than 80 kN/m.
- The Isolitest part of the LWAgeolight project has provided a proposal for a Nordtest method with requirements and related test methods for verification of characteristic properties of LWA. The Nordtest method is currently being circulated on national level for comments and is forwarded as basis for a new work item in CEN. The use of insulation in road may give increased risk of surface icing.
- The LWAgeolight project has evaluated the risk for surface icing and has proposed a method for determining the required level of documentation of the surface icing risk by use of LWA as frost insulation in roads.