Fort Worth started as a modest army outpost on the Trinity River bluffs, but the city really took shape when the railroads arrived in 1876 and turned it into a livestock shipping hub. That early growth laid down a patchwork of streets over the Eagle Ford shale and the expansive clays of the Woodbine Formation, soils that have been swelling and shrinking under Texas heat ever since. Concrete pavements here face a different set of demands than what you'd design for Dallas or Arlington. The subgrade isn't just something to pave over; it's an active layer that moves with every rainstorm and drought cycle. Our lab has spent years working with rigid pavement design in this specific geology, and we've learned that getting the slab thickness right depends entirely on understanding what lies beneath. When a contractor calls us about cracking in a warehouse floor or a municipal road showing faulting at the joints, we start with the soil, because in Fort Worth, the concrete is only as good as the ground it rests on.
In Fort Worth's expansive clays, a rigid pavement isn't just a concrete slab. It's a structural layer that has to breathe with the soil beneath it.
Technical details of the service in Fort Worth
Demonstration video
Risks and considerations in Fort Worth
We use a portable falling weight deflectometer and a nuclear density gauge on-site, because the kind of subgrade variability you find in Fort Worth doesn't show up in a single test pit. One corner of a site might sit on weathered shale with decent bearing, while the other end is gumbo clay that you can roll into a ball in your hand. The biggest risk we see isn't the traffic loading. It's the differential movement that happens when moisture gets under the slab edges through poorly sealed joints. Once water infiltrates the subbase, the clay swells unevenly, and you start seeing corner breaks and step faulting that no amount of steel reinforcement can fix after the fact. That's why our rigid pavement design reports always include a drainage evaluation and joint sealing specification tied to the local rainfall intensity data from the Fort Worth watershed. When a client tells us they want to skip the subgrade preparation to save schedule, we show them photos of what a Tarrant County parking lot looks like after two wet seasons without it.
Our services
Every rigid pavement design we deliver for Fort Worth projects includes three core technical phases, because skipping any one of them leads to the kind of premature failures we've seen too many times in this region.
Subgrade Characterization and Stabilization Design
We sample the upper four feet of subgrade across the full pavement footprint, run Atterberg limits and sulfate content tests, and design a lime or cement stabilization mix that targets a minimum 50 psi unconfined compressive strength after seven days of curing.
Concrete Mix Verification and Joint Layout
Our lab casts flexural beams from the proposed mix design and breaks them at 7 and 28 days per ASTM C78. We also produce a jointing plan with dowel and tie bar schedules, accounting for the slab geometry and the expected temperature gradient in the Fort Worth climate zone.
Construction Phase Quality Control Testing
During placement, we run slump, air content, and unit weight tests on every truck, plus in-place density on the stabilized subbase using a nuclear gauge. We also pull cores at 28 days when the specification requires verification of in-situ strength.
Frequently asked questions
What kind of subgrade preparation does a rigid pavement need in the Fort Worth area?
The preparation depends on the plasticity index of the native soil. For clays with PI values above 25, which cover much of the city, we typically recommend removing the top 12 to 18 inches and replacing it with a lime-stabilized layer compacted to 95% of modified Proctor density. The lime percentage is determined by Eades and Grim pH testing in our lab, usually falling between 4% and 6% by dry weight for the local Eagle Ford-derived soils.
How much does rigid pavement design and testing cost for a typical commercial project in Fort Worth?
For a standard commercial parking lot or warehouse slab in the Fort Worth area, the complete package of subgrade investigation, mix design verification, and construction-phase testing generally falls between US$2,130 and US$5,530. The range depends on the number of borings, the size of the slab area, and how many days of field testing are required during the concrete pour.
Do you use the AASHTO 93 method or the MEPDG for rigid pavement thickness design?
We primarily use the AASHTO 1993 design guide because it remains the standard referenced by most Texas municipalities and commercial specifications. However, we calibrate the key inputs, specifically the subgrade resilient modulus and the joint load transfer coefficient, using local performance data rather than national defaults. For larger TxDOT projects where MEPDG is specified, we can run the AASHTOWare Pavement ME software using site-specific traffic spectra and Fort Worth climate files.
What causes joint faulting in rigid pavements, and how do you prevent it?
Joint faulting happens when water infiltrates through unsealed joints, saturates the subbase, and erodes fine material from under the leave slab. When heavy axle loads hit the approach slab, it deflects downward and pumps the water and fines out, gradually creating a step. We prevent it by specifying adequate dowel bars, a dense-graded and stabilized subbase, and a hot-pour joint sealant installed as soon as the saw cuts are clean and dry, before the first rain event hits the fresh pavement. More info.