Equipment World Digital Magazine
Issue link: https://read.dmtmag.com/i/953148
EquipmentWorld.com | March 2018 51 A fter Hurricane Harvey and more than 40 inches of rain swamped the Houston area, the floodwaters slowly reced- ed to reveal one positive sign: the Texas DOT freeway system within the city was intact. Survival of that infrastructure points to the high resiliency of continuously reinforced concrete paving (CRCP) after flooding and other disasters, says Elizabeth Lukefahr, executive director of the Texas Concrete Pavement As- sociation. "When the waters receded, other than cleaning up debris, there was no repair of any (CRCP) section of Texas DOT's pavements in the city that were flooded," says Lukefahr. For many of those pavements, it was the third time they had flooded in 15 years. In a state already committed to CRCP as its primary concrete pave- ment, the freeways' ability to weather the flood brought a fresh look at why spending more upfront to install CRCP makes sense, says Lukefahr. With Texas, Illinois and California leading CRCP use, other states are beginning to incorporate it, such as Virginia, Oklahoma and New Mexico. Indiana recently used CRCP – which requires less concrete thickness com- pared to jointed plain – to rebuild the interstate pavement under a bridge that needed higher clearance because road technology | by Joy Powell | JoyPowell@randallreilly.com CRCP roadways proved resilient after Hurricane Harvey – and states are taking note I n Texas, roads are being torn apart by the heavy loads of energy-bearing trucks, giving impetus for a new research project. Mike Plei, an indepen- dent CRCP consultant from Illinois, has teamed with the Cement Council of Texas and researchers at the University of Texas at El Paso to per- form a CRCP finite element analysis, which measures the strength of a road's layers. "Elastic layer theory allows testing and analysis to see if local materials and possibly recycled materi- als can be used given the expected wheel loads, envi- ronment and individual layer strengths," Plei says. The layers start with a thin asphalt interlayer under the concrete slab, Plei explains. Next is an aggregate base or a treated base. The treated base can be suitable soil treated with cement or lime. That's all placed on existing soils. There can be a lot of choices for the layers, and most states have set treat- ments that have performed adequately, he says. "The lower layers are a lot cheaper, so if you can make them stronger, then you can reduce the expensive layers on the top," Plei says. New 'elastic layer theory' testing aims to cut con- struction costs while strengthening roads Source: TxDOT. Freeways in the downtown Houston area with continuously reinforced concrete pavement (CRCP) remained intact after Hurricane Harvey. "It is the joint area where many distresses occur in concrete pavement. This could certainly be one of the reasons why CRCP outper- forms jointed concrete pavement," says TxDOT spokesman Danny Perez.