a collaboration between ondřej císler of AOC architects and petr tej of klokner institute at CTU in prague sees the fabrication of the ultra-lightweight concrete ‘bridge over the dřetovice stream.’ the project is situated across a walking trail leading to a cemetery outside the czech village of vrapice. the picturesque wildness of its natural context serves to contrast the urban atmosphere of the village. the meadowed landscape surrounding the bridge is subject to constant changes due to the floods. the design of the bridge is driven by the ethereal concept as a ‘portal between the world of the living and the dead’ and investigates the limits of its extremely lightweight and technologically advanced material.

aoc concrete bridge
all images by boysplaynice



ondřej císler at AOC architects and petr tej of klokner institute at CTU in prague make use of advanced concrete casting technology in the development of the bridge over the dřetovice stream. with a ten meter span, the structure is fabricated of freeze-resistant, fiber-reinforced, ultra-high performance concrete (UHPC). the subtlety of the form together with the length of its span is overcome with a doubly-curved geometry, stabilizing the construction and easily bracing the bridge in both directions. with a cross-sectional width of 1.5 meters and a total material usage of 1.4 cubic meters, the bridge weights approximately 3.5 tons.

aoc concrete bridge



during the verification of the structural design and the concrete casting technology, a prototype was built and subjected to load testing. pigment was added into the concrete mixture, surface patina etched and the key details hand sanded. opposite the bridge is ‘the guardian,’ a sculpture designed by the studio of jan hendrych. among other fields, the artist is a leading expert on baroque sculpture within the context of bridges and landscapes. the sculpture is based on the original baroque archetypes and situated within the landscape to complete the entire spatial composition of the bridge.

aoc concrete bridge aoc concrete bridge aoc concrete bridge aoc concrete bridge aoc concrete bridgeaoc concrete bridge 



project info:


project title: bridge over the dřetovice stream

architecture: AOC architects, klokner institute at CTU in prague

lead designers: ondřej císler (AOC architects) and petr tej (klokner institute at CTU in prague)

location: kladno, vrapice, czech republic

material: ultra-high performance concrete

client: city of kladno

sculpture: jan hendrych

casting technology: jiří kolísko

manufacturer: kš prefa

area: 19.5 square meters

completion: 2019

photography: boysplaynice