compatibility of ultra high performance concrete as repair material
compatibility of ultra high performance concrete as repair material
compatibility of ultra high performance concrete as repair material
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
2.1.3.4 Environmental Impact <strong>of</strong> UHPCAs previously described, the use <strong>of</strong> UHPC allows building cross sections with the samebearing capacity <strong>as</strong> those <strong>of</strong> reinforced <strong>concrete</strong> with significant reduction <strong>of</strong> dimensions.Consequently, it seems re<strong>as</strong>onable to state that the use <strong>of</strong> UHPC reduces theenvironmental impact <strong>of</strong> the construction industry. Nonetheless a further analysis needsto be done in order to draw that conclusion due to the fact that to yield 1 yd 3 <strong>of</strong> UHPC,large amounts <strong>of</strong> cement and superpl<strong>as</strong>ticizer need to be used. The Global WarningPotential (GWP), which is a relative me<strong>as</strong>ure that compares the greenhouse g<strong>as</strong>, isusually used for a realistic environmental analysis. Several researchers have compared, interms <strong>of</strong> GWP, UHPC constructive solutions against others conventional alternativessuch <strong>as</strong> a steel girder bridge with a c<strong>as</strong>t-in-place <strong>concrete</strong> deck (Perry 2011) or a layer <strong>of</strong>normal <strong>concrete</strong> with waterpro<strong>of</strong>ing membrane (Denarié et al. 2009b). Their analysisshowed that a reduction <strong>of</strong> raw <strong>material</strong>s consumption and <strong>of</strong> the emissions <strong>of</strong> CO 2 canbe achieved by using UHPC. Denarié et al. (2009b) stated that if durability <strong>of</strong>rehabilitation is taken into consideration, a UHPC, developed with common <strong>material</strong>s,would produce around the 50% <strong>of</strong> GWP <strong>of</strong> that <strong>of</strong> conventional solution (normal <strong>concrete</strong>with waterpro<strong>of</strong>ing membrane). In addition, UHPC will further incre<strong>as</strong>e the service lifein order <strong>of</strong> magnitude <strong>high</strong>er than normal <strong>concrete</strong>.2.2 Rehabilitation <strong>of</strong> Concrete StructuresTransportation agencies are spending a significant portion <strong>of</strong> their budgets to <strong>repair</strong>infr<strong>as</strong>tructures that have failed prematurely due to rapid deterioration. There is anincre<strong>as</strong>ing need to develop better <strong>repair</strong> techniques that guarantee the success <strong>of</strong> therehabilitation and keep the number <strong>of</strong> repeat interventions to a minimum. Currently, thereis a wide range <strong>of</strong> solutions that have been used for the rehabilitation <strong>of</strong> <strong>concrete</strong>structures that are yielding excellent results for some specific applications, but still thereis a need to develop a <strong>material</strong> capable <strong>of</strong> extending the service life longer than 20 yearsin harsh environmental with a minimum <strong>of</strong> maintenance. UHPC with its remarkablecharacteristics <strong>as</strong> a <strong>repair</strong> <strong>material</strong> for <strong>concrete</strong> structures in harsh environmental16
Change language