{"id":2886,"date":"2024-12-30T14:43:32","date_gmt":"2024-12-30T14:43:32","guid":{"rendered":"https:\/\/prairieprod.vcnastaging.com\/?p=2886"},"modified":"2024-12-30T14:43:32","modified_gmt":"2024-12-30T14:43:32","slug":"driving-the-future","status":"publish","type":"post","link":"https:\/\/www.prairie.com\/fr\/driving-the-future\/","title":{"rendered":"Driving the Future"},"content":{"rendered":"

Of all the riding surfaces owned and maintained by the\u00a0Illinois Tollway<\/a>, bridges are by far the most vulnerable to decay.<\/p>\n

\u201cThese unsupported spans are up in the air, facing extreme stresses every day,\u201d explains Tollway Deputy Program Manager for Materials\u00a0Steve Gillen<\/strong>. \u201cHeavy salting in cold weather drives damage, too. Chloride finds its way through even the tiniest cracks, corroding steel reinforcement and accelerating bridge failure.\u201d<\/p>\n

Ultimately, that\u2019s bad news for the 1.4 million drivers who ride the Tollway system daily \u2013 and suffer frustrating delays whenever spans must be rebuilt.<\/p>\n

Pushing for a solution<\/h2>\n

\"\"<\/p>\n

More than a decade ago, Tollway engineers sought to develop a new high-performance concrete (HPC) mix for exclusive use in maintaining the system\u2019s 642 bridge decks.<\/p>\n

\u201cOur first mixes focused on minimizing permeability to chloride,\u201d says Gillen, \u201cbut we experienced even more cracking. So we shifted our thinking, choosing stain\u200bless steel reinforcement to minimize corrosion, and aimed for maximum crack control.\u201d<\/p>\n

The Tollway partnered with\u00a0CTLGroup<\/strong>\u00a0in Skokie, Illinois, to develop performance-based specifications and produce trial batches of the first anti-crack mixes. As work continued, they formed a technical review panel of contractors and suppliers (including Prairie experts) and representatives of the\u00a0Illinois Department of Transportation<\/strong>.<\/p>\n

Proprietary mix cures from the inside out<\/h2>\n

Working with CTL\u2019s specs, Prairie\u2019s mix development team explored a range of solutions. The resulting P2P mix will deliver 75 to 100 years of service, up to 3 times the current lifespan of bridges in the Tollway system.<\/p>\n

Prairie\u2019s proprietary formula uses saturated lightweight fines to help the concrete cure from the inside out, explains Prairie Regional Sales Manager\u00a0Rich Shadle<\/strong>.<\/p>\n

\u201cThe fines are a coarse, manufactured sand that\u2019s light and highly absorbent,\u201d Shadle notes. \u201cThey are pre-wetted and added to the mix. Following placement they release moisture, acting as an internal curing agent to control natural shrinkage as the deck hardens.\u201d<\/p>\n

Figuring out precisely the right amount of fines to add to the ternary blend \u2013 composed of cement, fly ash, slag and other cementitious materials \u2013 was crucial, Shadle says. \u201cWe sought the ideal mixture proportioning to balance the water supplied by the pre-wetted fines with that demanded by the hydrating cement paste in the mixture.\u201d<\/p>\n

Joint-free spans will resist decay<\/h2>\n

Crews from\u00a0Dunnet Bay Construction<\/strong>\u00a0of Glendale Heights, Illinois rebuilt 3 Tollway bridges this season using the new mix. All spans are part the Jane Addams Memorial Tollway (I-90) between Elgin and Rockford.<\/p>\n

The new decks were designed without joints to minimize deterioration at those stress points. \u201cUsing the concept of integral abutment bridges, we placed jointless spans of up to 550 feet,\u201d says Gillen. Most Tollway bridge lengths are only several hundred feet, he notes.<\/p>\n

Prior to the pours, experts at CTL worked with Prairie\u2019s Yard 14 to test and certify the new mix. Yards 14 and 19 provided more than 1,000 yards for the subsequent projects, including the Powers Road crossroad bridge, a 350-foot span just west of the Elgin toll plaza (shown in photos).<\/p>\n

\u201cAir entrainment was also crucial to ensure durability ,\u201d says Prairie\u2019s Technical Services Director and QC expert\u00a0Steve Fleming<\/strong>. \u201cEach load at Powers Road was tested for compliance with the 5% to 8% requirement, and we tested several loads after placement since, due to site restrictions, workers used a collapsible conveyor system instead of pumping the concrete.\u201d<\/p>\n

Innovation for a stronger infrastructure\u200b\u200b<\/h2>\n

\"\"<\/p>\n

Prairie is proud to serve as the Tollway\u2019s partner in developing better mixes for bridge and road construction, Fleming says. \u201cWe appreciate the Tollway\u2019s leadership in pushing for innovative solutions that can be used by other road and bridge builders to improve our infrastructure.\u201d<\/p>\n

With the largest QC staff in its service area, Prairie is well-positioned to meet the needs of Tollway contractors going forward, he adds. \u201cWe also have the greatest number of plants and trucks near the various sites,\u201d he says, \u201cso we look forward to more projects as the Tollway\u2019s 12-year renewal project moves forward.\u201d<\/p>","protected":false},"excerpt":{"rendered":"

Of all the riding surfaces owned and maintained by the\u00a0Illinois Tollway, bridges are by far the most vulnerable to decay. \u201cThese unsupported spans are up in the air, facing extreme stresses every day,\u201d explains Tollway Deputy Program Manager for Materials\u00a0Steve Gillen. \u201cHeavy salting in cold weather drives damage, too. Chloride finds its way through even […]<\/p>","protected":false},"author":1,"featured_media":2887,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[],"class_list":["post-2886","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorized"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.prairie.com\/fr\/wp-json\/wp\/v2\/posts\/2886","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.prairie.com\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.prairie.com\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.prairie.com\/fr\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.prairie.com\/fr\/wp-json\/wp\/v2\/comments?post=2886"}],"version-history":[{"count":0,"href":"https:\/\/www.prairie.com\/fr\/wp-json\/wp\/v2\/posts\/2886\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.prairie.com\/fr\/wp-json\/wp\/v2\/media\/2887"}],"wp:attachment":[{"href":"https:\/\/www.prairie.com\/fr\/wp-json\/wp\/v2\/media?parent=2886"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.prairie.com\/fr\/wp-json\/wp\/v2\/categories?post=2886"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.prairie.com\/fr\/wp-json\/wp\/v2\/tags?post=2886"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}