Researchers at the Indian Institute of Technology, Roorkee (IITR) have found that thermocol or expanded polystyrene (EPS) can withstand seismic forces on buildings up to four stories high.

Researchers tested a large-scale building and a number of wall elements constructed from thermocol sandwiched between two layers of concrete at the Department of Earthquake Engineering’s National Seismic Test Facility (NSTF), IIT Roorkee.

This was developed under the Science and Technology Infrastructure Improvement Fund (FIST) program of the Indian government’s Department of Science and Technology (DST), a statement from the Department of Technology said on Monday. Science and Technology.

Adil Ahmad, the researcher who conducted the tests, assessed the behavior of the constructions under lateral forces, as the earthquake causes a force mainly in the lateral direction.

The project was completed with a detailed computer simulation of a realistic four-storey building. Overseeing the research, Yogendra Singh, professor at IITR, informed that the analysis shows that a four-story building constructed with this technique is able to withstand seismic forces, even in the most seismic area of ​​the country, without no additional structural support.

The researchers attributed this earthquake-resistant ability to the fact that the EPS layer is sandwiched between two layers of concrete, with reinforcement in the form of welded wire mesh.

The researchers said that the force applied to a building during an earthquake is due to the effect of inertia and therefore depends on the mass of the building. Thermocol resists earthquakes by reducing the mass of the building.

In this technique, the EPS core and the wire mesh reinforcement are produced in the factory. The skeleton of the building is first erected from the core and factory-made reinforcing panels, then concrete is sprayed onto the core of the skeleton. This technique does not require any formwork and can therefore be built very quickly, the researchers said.

In addition to resisting earthquakes, the use of an expanded polystyrene core in the concrete walls of a building can result in thermal comfort. The core provides the necessary insulation against heat transfer between the interior and exterior environment of the building.

It can help keep the interior of the building cool in hot and warm environments in cold weather. India suffers from a great variation in temperature in different parts of the country and during different seasons of the year. Therefore, thermal comfort is a critical consideration along with structural safety.

“The technology also has the potential to save building materials and energy, with an overall reduction in the carbon footprint of buildings. It replaces a large part of the concrete volume of the walls and the floor / roof.

This replacement of concrete with extremely lightweight EPS not only reduces mass, thereby decreasing the seismic force acting on a building, but also decreases the load on the natural resources and energy required to produce cement concrete, the statement added. .