I think it should be 'postensada'.

Architect Barry Kendell from Sheppard Robson was keen to use stone on the new build element of the redevelopment of No1 Southampton Row in London but also wanted the floor-height mullions to be elegantly slender. To satisfy both requirements, the stone was produced as post-tensioned columns, which also had the added advantage of speeding up the construction of the stonework on site. With sandstone and limestone used in the retained facade, the planners did not insist on any particular stone being used and Cadeby magnesian limestone from Yorkshire was suggested by the stone contractors, Grants of Shoreditch, and selected. The columns stand on transoms of the same stone that transfer the weight back to the floor plate via corbel plates.

http://www.stonespecialist.com/news/market-intelligence/site...

--------------------------------------------------
Note added at 45 mins (2016-12-03 00:05:44 GMT)
--------------------------------------------------

La Sagrada Família de Barcelona iniciarà en octubre la construcció de la torre de María amb la tècnica de la pedra postensada, un mètode que s’usarà per a les sis torres centrals i que consisteix a unir panells prefabricats de pedra amb una estructura interna d’acer inoxidable, ha explicat l’arquitecte director de la basílica, Jordi Faulí.

http://www.vilaweb.cat/noticies/la-sagrada-familia-iniciara-...

--------------------------------------------------
Note added at 50 mins (2016-12-03 00:10:54 GMT)
--------------------------------------------------

Damian Eley’s talk will describe how Arup is helping to complete Gaudi’s masterpiece by developing the design of six great new spires using post-tensioned stone masonry.

http://uk.uli.org/event/innovators-disrupters-sagrada-famili...

This October, the Sagrada Familia will embark upon a final ten-year transformation for ultimate completion in 2026, marking the centenary of Antoni Gaudí's death.

For the first time in a project of such magnitude, construction workers will be using post-tensioned concrete, combining pre-made panels of stone weighing up to 24 tons and measuring some five metres in height.

Their latest project is the Torre de María, where this groundbreaking technique will be used for the first time. After the Torre de Maria, work will begin on the Torre de Jesucristo, the tower of Jesus Christ and the building's central spire, which will stand an imperious 140 metres above the ground and change the cityscape forever.

http://www.easyvoyage.co.uk/travel-headlines/gaudi-s-vision-...