Detalis of seismic house from Finale Emilia new construction with Porotherm BIO PLAN 45
Behind a seismic house from Finale Emilia new construction with Porotherm BIO PLAN 45

Brick buildings for seismic prone areas

House built with Wienerberger clay blocks in the Italian region of Emilia Romagna that withstood the earthquake in May 2012.

Earthquake-resistant construction

The main objective of earthquake-resistant construction is to protect people and buildings during seismic activities.

Earthquake-resistant construction covers a wide range of activities to design, outfit and/or renovate buildings to make them capable of withstanding earthquakes up to a specific magnitude.

We have addressed this challenge and developed a variety of solutions for earthquake-prone areas. Among others, we have been involved in international research projects on the dimensioning, design and construction of brickwork structures in seismically threatened zones. These many years of research led to the development of a number of products, including a special type of brick whose properties make it particularly well-suited for earthquake-prone areas.

Porotherm seismic clay block

Extensive research formed the basis for this development

The patented Porotherm seismic clay block is a special brick whose properties guarantee higher relevant masonry strength and make it particularly well suited for earthquake-prone areas. It has a specially shaped vertical mortar pocket with a unique mortar window that forms a tooth connection between the block and the mortar in the butt joint. This creates an excellent bond with the mortar and increases mechanical strength.

Buildings constructed with these clay blocks are substantially more resistant to the types of horizontal displacements that occur during an earthquake. This has been indicated by various analyses in the test series: “Seismic Test Program of special designed clay blocks due to earthquake resistance by Wienerberger consisting real scale shaking table-, cyclic shear-, diagonal tension- and compression tests“.

Shaking table tests on real scale buildings

Testing our products

We constantly develope and test our products, in order to provide the best quality and highest safety for our customers. A full-scale seismic testing of modern unreinforced insulation filled clay blocks, has been conducted in form of so called shaking table tests.

The requirements of clay block masonry building constructions changed drastically during the last decades. Besides mechanical strength, also thermal insulation is becoming more and more important. Following this trend Wienerberger has successfully developed a series of insulation filled clay blocks.

New product developments run through a series of tests concerning their strength. In order to test its loadbearing capacity under seismic events, Wienerberger initiated an applied research project together with external European experts. In the course of this research, shaking table tests on real scale buildings have been conducted, as these tests deliver most reliable results. 

For this purpose, two mock-ups with different geometries were tested on 3-D shaking tables, using a series of seismic records with increasing intensity. After analysing the data, comparative calculations and the comparison with current standards, the results have been reviewed, which confirmed the excellent performance of the products tested.

The results

Even after more than 50 shakes with increasing ground accelerations (seismic inputs), the buildings tested, showed excellent seismic behaviour. The strength of the two models was even higher than predicted by calculations that have been conducted before the tests. In conclusion, this research confirmed that insulation filled clay blocks can be used in seismic areas without hesitation and that - following the relevant standards – buildings constructed with Wienerberger insulation filled clay blocks provide safety even in the case of earthquakes.