CÚPU LA DE LA SALA DEL SIGLO EN BRES LAU, 1911-
ZEISS FACTOR\', JENA, ALEMAN IA, 1925. OYCKER-
MERCADO DE BAS IL EA, SU IZA,1929. HANS E. RY H l-
1913. MAX BERG. DYCKERHO FF ANO W I DMAN
HOFF ANO W I DMAN
NER, F. DISCH INGER Y A. GÓENNER
T2
INTERNATIONAL CONTEXT: FROM REINFORCED CONCRETE SPATIAL ROOFS TO MODERNIST ARCHITECTURE' S THIN SHELLS
Th e adve nt of rein forced co ncrete in the earl y twe ntieth ce ntury revo lutionised c ivil w orks and buildin g. En gineers w orl d-wid e soon rea lised th at they co uld ca pitali se o n th e strength and formal ve rsatility of thi s new materi al and its unquesti onab le preeminence over iro n in term s of fire perfo rm ance to build bri dges and roofs w ith ve ry long spans. lnitia ll y (1900- 1920), rein forced co ncrete spa ti al roofs imitated th e spa ti al w rought iron frames popul ar in the nineteenth ce ntury, based on lattices or co ntinuous seri es of arches or deep bea ms. Co nstructi on on w hat is intern atio nall y regard ed as th e first reinfo rced co ncrete thin shell was co ncluded in Jena, Germ any, in 1925. From th at time on, w ith th e di scovery of a technologica l language specifi c to thi s new materi al, th e aim was to further develop the thin shell model. Shortly th ereafter, in 1929, the first ln te rn ati onal Con gress of M odern Architec ture co nsolida ted th e new "ai r" that was bringing radi ca l change to ali disciplines: architecture, engineering, mu sic, pai nting, sculpture, poetry... In the decades that fo ll owed, thin co ncrete shell s also beca me th e ul timate symbo l of th at new paradigm (" less is more"), co nsti tuting th e core of a broa d legacy of new, effective and ess entially bare structural form s. . O ne of the first roofs to be made of rein fo rced co ncrete covered th e tin y Bürkli platz Pavilio n built by Ro bert M aill art in 1908, w ho in ve nted his mu shroom-li ke slab th at sa me year. Just one yea r later, in 1909, the Swa nson Brothers built th e roof over the M elbourne Publi c Library, an octagonal dome measuring 34.8 metres in diameter, at th e tim e th e largest such rein fo rced co ncrete stru ctu re ever buil t. In 1913 its record was approp ri ated by the Jahrhunderh ale (Cente nnial Hall) at Bres lau, Po land, w hose 65-metre di ameter roof was designed by architect M ax Berg, engineered by W illi Gehl er and GüntherTrauer and built by th e pio neer German fi rm Dyckerhoff and Widm an. Fun ct ionall y speak ing, th e primary characteri stic of these large rein fo rced co ncrete roofs was that they imitated their predecesso rs, spatial w rought iro n roofs. Sho rtl y after lldefo nso Sá nchez de l Río Pi són undertook hi s engineerin g ca reer in 1922, he was des ignated muni cipal engin eer of th e City of Oviedo. Th at app ointment ca rn e in 1924, w hen th e wo rld ' s first thin shell was under co nstru cti on at Jena, Germany, autho red by Walte r Bauersfe ld and built by Dycker hoff and Widm an under the o rders of that fi rm's chi ef engin eer, Franz Di schin ger. Th at feat fo ll owed o n Eu ge ne Freyss in et' s des ign, in 1923 , fo r hi s famous hanga rs at Orly: cy lindri ca l ba rrel va ul ts w ith a parabo li c cross-secti o n and co rru gated surface, 144 metres lo ng and spa nning a di stance of 75 metres . Th ese events we re to change th e desti ny of rein fo rced co ncrete spatial roofs in the deca des th at fo ll owed. Give n the cli fficulty inherent in engineering th ese in cipient thi n shell s, in th e nineteen twe nties, at the outset of hi s ca reer, Sá nchez del Río cleve loped hi s own meth ocl fa r rein fo rcecl concrete roof cl esign. He basecl their stru cture on geometri c shapes th at coulcl be simpl y built and cli mensioned with fra mes co nsistin g of co ntinuous ribs (bea ms or arches) set on their narrow side and lightweight severy-like elements in between to minim ise the overa ll we ight of the roof. Thi s was th e model he used in his fa mous ea rl y " umbrella"- like roofs, as ·w e ll as in th e roofs over wate r ta nks ancl the si ngul ar roof over th e Pa la de Siero M arket (1929), w ith its two intersecting cy lindri ca l barrel va ults, fo r w hi ch he designed a hi ghl y ori ginal arch that spans 50 metres. Th e co nstruction of thi s inn ovative roof conc urred w ith three legendary stru ctures in the history of thin co ncrete shells: the Frankfurt Ma rket Hall (1926- 1927), designed by Martín El sasser, Fra nz Dischinger and Ulri ch Finsterwa lder; th e Leipzig Ma rket (1927- 1929), cl es ignecl by Hubert Ritter, Franz D ischinger and Hubert Rüsch and the Basel M arket (1929) an octagonal dome 60 metres in diameter and onl y 8 cm thick, des igned by Hans E. Ryhiner, Franz Di schinger and A lfred A. Goenn .
20
I LDEFONSO SÁNCHEZ DEL RÍO PISÓN. El INGENIO DE UN LEGADO
elr.'JDACIÓN JUANhLO TURRIAl\O