THE CONCRETE BRIDGE MAGAZINE

SUMMER 2016

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/697527

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F H WA 46 | ASPIRE Summer 2016 O wners acr oss the United States and C a n a d a a r e r e c o g n i z i n g t h e v a l u e p a i r i n g u l t r a - h i g h - p e r fo r m a n c e c o n c r e t e ( U H P C ) c o n n e c t i o n s t e c h n o l o g y a n d p r e f a b r i c a t e d b r i d g e e l e m e n t s t o b u i l d r o b u s t s t r u c t u r e s . S t r u c t u r a l c o n n e c t i o n s m u s t p e r f o r m a t l e a s t a s w e l l a s t h e connected element s, but traditional field- c a s t c o n n e c t i o n s h a v e a t t i m e s p r o v e d t o b e d i f f i c u l t t o f a b r i c a t e , d i f f i c u l t t o i n s t a l l , e x p e n s i v e , a n d s u s c e p t i b l e t o u n d e r p e r f o r m a n c e . T h e e x c e p t i o n a l m e c h a n i c a l a n d d u r a b i l i t y p r o p e r t i e s o f UHPC open doors to field-cast connections t h a t s i m p l i f y c o n s t r u c t i o n w h i l e s i m u l t a n e o u s l y d e l i v e r i n g a s t r u c t u r e a n t i c i p a t e d t o m e e t l o n g s e r v i c e l i f e demands. A d v a n c e s i n c o n c r e t e t e c h n o l o g y, i n c l u d i n g f i b e r r e i n f o r c e m e n t , s u p e r p l a s t i c i z e r s , p a r t i c l e p a c k i n g , a n d s u p p l e m e n t a r y c e m e n t i t i o u s m a t e r i a l s , began to be packaged together into a new g e n e r a t i o n o f c e m e n t i t i o u s c o m p o s i t e m a t e r i a l s i n t h e 1 9 7 0 s a n d 1 9 8 0 s . C o m m e r c i a l i z a t i o n i n t h e 1 9 9 0 s b r o u g h t to market a new class of materials referred t o a s U H P C . Av a i l a b l e t o d a y p r i m a r i l y f r o m m a j o r c o n s t r u c t i o n m a t e r i a l s s u p p l i e r s , b u t a l s o l i k e l y a v a i l a b l e s o o n a s a l o c a l l y s o u r c e d p r o d u c t , U H P C i s gaining widespread attention in American a n d C a n a d i a n m a r k e t s a s a f i e l d - c a s t g r o u t . M a r k e t c o n d i t i o n s a n d o w n e r e x p e c t a t i o n s i n o t h e r p a r t s o f t h e w o r l d are creating alternative focal point s, such as using pr efa bricated UHPC component s for cur tain walls and fa├žades, pedestrian bridges, urban furniture, and even security applications. Deployment of UHPC Connections Deployment s of UHPC connections have shown significant grow th in recent years, w i t h m o r e t h a n 1 3 0 b r i d g e s a l r e a d y i n s e r v i c e . T h e f i r s t b r i d g e s t o e n g a g e t h i s c o n c e p t w e r e c o n s t r u c t e d i n O n t a r i o s t a r t i n g i n 2 0 0 5 , a n d i n N e w Yo r k S t a t e star ting in 2009 (Fig. 1 and see ASPIRE TM Fa l l 2 0 0 9 ) . D o z e n s o f n e w d e p l o y m e n t s are happening each year, with experienced o w n e r s m o v i n g t o i n s t i t u t i o n a l i z e t h e t e c h n o l o g y a n d n e w o w n e r s e n c o u r a g i n g first installations. A s shown in Fig. 2, the e a r l y a d o p t e r s h a v e c o n t i n u e d t o p r e s s for ward with use of this technology as the broader community comes on board. The robustness of the UHPC connections h a s r e s u l t e d i n a f e w h i g h p r o f i l e d e p l o y m e n t s w h e r e i n o w n e r- d e f i n e d r e q u i r e m e n t s s t i p u l a t e d t h a t t h e o v e r a l l f i n i s h e d s t r u c t u r e n e e d e d t o h a v e a n e x c e p t i o n a l l y l o n g s e r v i c e l i f e . T w o o n g o i n g e x a m p l e s i n c l u d e t h e r e d e c k i n g o f t h e 3 . 5 - m i l e - l o n g P u l a s k i S k y w a y i n N e w a r k , N . J . , a n d t h e c o n s t r u c t i o n o f t h e N i p i g o n R i v e r B r i d g e b y t h e O n t a r i o Ministr y of Transpor tation on the Trans- Canada Highway. Two upcoming examples a r e t h e r e h a b i l i t a t i o n o f t h e F r a n k l i n Avenue Bridge over the Mississippi River in Minneapolis, Minn., and the Major Deegan Expressway in New York City. FHWA Every Day Counts Support T h e Fe d e r a l H i g h w a y A d m i n i s t r a t i o n 's ( F H W A ' s ) E v e r y D a y C o u n t s ( E D C ) pr ogram, now in it s six th year, is gear ed t o w a r d a d v a n c i n g e f f e c t i v e , p r o v e n , market-ready technologies into widespread u s e . F H WA's Tu r n e r- F a i r b a n k H i g h w a y R e s e a r c h C e n t e r b e g a n i n v e s t i g a t i n g t h e u s e o f U H P C i n 2 0 0 1 , l e a d i n g t o t h e e v e n t u a l d e v e l o p m e n t a n d d e l i v e r y o f o p t i m a l s o l u t i o n s t h a t a r e i n u s e t o d a y. Given the level of market adoption in 2014, it was decided to include UHPC connections a s o n e o f t h e 1 1 t e c h n o l o g i e s w h o s e deployment is being suppor ted via EDC in 2015 and 2016. The EDC program provides stakeholders w i t h t h e a s s i s t a n c e t h e y n e e d t o s u c c e s s f u l l y d e m o n s t r a t e , i n t e g r a t e , a n d i n s t i t u t i o n a l i z e a t e c h n o l o g y i n t o t h e i r t o o l b o x o f s o l u t i o n s . F o r U H P C connections, the deployment suppor t team is delivering workshops across the countr y, is facilitating site visits to ongoing projects, i s s u p p l y i n g e x p e r t t e c h n i c a l a s s i s t a n c e , a n d i s d e l i v e r i n g t h e s u p p o r t c o n t e n t ( f o r e x a m p l e , d e s i g n a n d c o n s t r u c t i o n guidance) needed by the adopting entity. A d m i t t e d l y, t h e s t r o n g i n t e r e s t i n U H P C connections technolog y has str etched the capacity of the deployment team, but the team is looking for ward to continuing to m e e t s t a k e h o l d e r n e e d s t h r o u g h o u t 2 0 1 6 and beyond. Fundamental Principles The fundamental mechanical principle u n d e r g i r d i n g t h e p e r f o r m a n c e o f U H P C connections is the fact that increasing the tensile resistance of concrete will allow it to better engage the connectors originating from a prefabricated concrete element. The tensile splitting and pullout behaviors that commonly limit the capacity of field-cast c e m e n t i t i o u s c o n n e c t i o n s a r e m i t i g a t e d Pairing Prefabricated Bridge Elements with UHPC Connections by Dr. Benjamin A. Graybeal, Federal Highway Administration Figure 1. Ultra-high-performance concrete connections were used in the bridge over the Canandaigua Outlet in New York. Photo: Federal Highway Administration.

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