ASPIRE is a quarterly magazine published by PCI in cooperation with the associations of the National Concrete Bridge Council. The editorial content focuses on the latest technology and key issues in the Concrete Bridge Industry.
Issue link: http://www.aspiremagazinebyengineers.com/i/296646
C R E AT I V E C O N C R E T E C O N S T R U C T I O N 28 | ASPIRE , Fall 2013 T w o b r i d g e s w e r e r e p l a c e d r e c e n t l y o v e r t h e e a s t a n d w e s t b r a n c h e s o f t h e Fox R i v e r i n d o w n t o w n A u r o r a , I l l . , the state's second largest city. The original b r i d g e s w e r e t h r e e - s p a n , f i l l e d s p a n d r e l arches constructed in 1909 of cast-in-place concrete. The bridges connect historic Stolp Island to the rest of Aurora, and were listed on the National Register of Historic Places. Historic pr eser vation criteria mandated that the completed appearance be similar to that of the original construction including arches, concrete railing, and lighting (as indicated on photographs from archives). To r e p l i c a t e a h i s t o r i c a p p e a r a n c e w i t h modern techniques, three spans of precast, p r e s t r e s s e d c o n c r e t e d e c k b e a m s , p r e c a s t concrete fascias in the shape of the original ar ches, pr ecast concr ete outlooks at each p i e r ( a l s o i n t h e s h a p e o f t h e o r i g i n a l outlooks), and precast concrete railings were specified. Period lighting (again based on archive photographs) was also installed. The original piers and abutments were removed to the waterline and reconstructed with cast- in-place concrete to the bearing elevations for the precast concrete elements. D e s i g n w a s c o m p l i c a t e d b y e x t e n s i v e utility conf lict s, lack of drawings for the existing bridges, and the abutments being integral with historic building foundations dating to the 1840s. The project was let for b i d i n S e p t e m b e r o f 2 0 1 1 b y t h e I l l i n o i s Depar tment of Transpor tation. Seven bids ranging from $6.8 million to $8.5 million w e r e r e c e i v e d . T h e c o n t r a c t wa s a wa r d e d on November 18, 2011. The city of Aurora held a grand re-opening and ribbon cutting ceremony for the new bridges on December 12, 2012. While the schedule for this high-profile project caused initial concerns among city o f f i c i a l s a n d b u s i n e s s o w n e r s , t h e u s e o f precast concrete architectural and structural e l e m e n t s a n d d r y w e a t h e r, a l l o w e d t h e contractor to meet an aggressive, one-year construction schedule. _______ Robert Davies is a senior professional with HR Green Inc. in McHenry, Ill. Reconstruction of Downer Place Bridges by Robert Davies, HR Green Inc. New precast, prestressed concrete deck beam bridge over the East Branch Bridge, as constructed in 2012. All photos: HR Green Inc. West Branch Bridge, constructed in 2012. AspireBook_Win14.indb 28 12/10/13 12:54 PM