McKinney sits on the geologic boundary where the Eagle Ford Shale meets the Austin Chalk, creating a mosaic of moderately expansive clay and weathered limestone within the same city block. At our lab just off US-75, we regularly see PI values jump from 18 to 42 between two borings 200 feet apart. Rigid pavement design here cannot rely on a textbook section copied from Houston or Dallas. The concrete slab must bridge small subgrade volume changes while resisting curling stresses from Collin County’s 95°F summer temperature swings. Our team runs the PCA thickness method on every project, adjusting the modulus of subgrade reaction with site-specific CBR and resilient modulus data.
For streets in the Craig Ranch area where fill depths exceed five feet, we routinely pair the pavement analysis with a CBR road test to validate compaction uniformity before specifying the concrete section, and we reference footing investigations when the pavement ties directly into building slabs to avoid differential movement at the interface.
A rigid pavement slab is only as reliable as the subgrade it floats on—skip the soil investigation and you’re guessing on k-value.
Methodology and scope
The subbase becomes the real protagonist in rigid pavement performance. We specify a minimum 4-inch cement-treated base where the sulfate content in the native soil exceeds 0.3%, which is surprisingly common in pockets near Wilson Creek. Our mix designs always incorporate TxDOT Class P concrete with a maximum w/c ratio of 0.45, and we verify flexural strength at 28 days using third-point loading per ASTM C78. For joint sealant selection, we default to silicone in heavy-truck lanes and preformed compression seals in collector streets.
Local considerations
McKinney’s population has doubled since 2010, pushing new subdivisions into marginal ground that older developments bypassed. The city’s average elevation of 630 ft masks localized low areas where the water table sits within four feet of finished grade during wet winters. When a rigid pavement section is placed over poorly drained clay without a capillary break, the slab bottom stays saturated, and curling combined with pumping at the joints erodes the subbase within three to five years. We saw this firsthand on a retail center off Eldorado Parkway: the original pavement design ignored the perched water condition, and joint faulting reached 0.4 inches by year four. Our forensic investigation pointed to a missing edge drain detail and an undersized dowel basket. Since then, every rigid pavement design we produce for McKinney includes a drainage analysis tied to the geotechnical profile, not just a standard cross-section.
Applicable standards
ACI 330R-08 (Guide for Design and Construction of Concrete Parking Lots), PCA EB109 (Thickness Design for Concrete Highway and Street Pavements), AASHTO 1993 / MEPDG (Mechanistic-Empirical Pavement Design Guide), ASTM C78 (Flexural Strength of Concrete), TxDOT Item 360 (Concrete Pavement)
Associated technical services
Subgrade Characterization & k-Value Testing
Site-specific borings with CBR, resilient modulus, and plate load tests where required, feeding directly into the PCA and AASHTO design procedures.
Jointing & Reinforcement Plans
Detailed joint layout drawings with dowel sizing, tie bar schedule, and sealant specification matched to the local temperature range and traffic category.
Forensic Evaluation & Rehabilitation Design
Distress surveys and FWD testing on existing rigid pavements, followed by full-depth repair or overlay design with bond-breaker recommendations.
Typical parameters
Frequently asked questions
What is the typical cost range for a rigid pavement design package in McKinney?
For a standard commercial lot or residential street segment, the geotechnical investigation and pavement design package runs between US$1,860 and US$6,320, depending on the number of borings, the need for plate load or FWD testing, and whether the project requires MEPDG-level analysis.
How do you account for the expansive clays east of Highway 75 in rigid pavement design?
We run Atterberg limits and sulfate tests on every sample from the upper five feet. When the PI exceeds 25 or the sulfate content surpasses 0.3%, we specify a cement-treated subbase, reduce joint spacing, and add a moisture barrier detail at the slab edge to minimize differential heave.
Do you use the AASHTO 1993 method or the MEPDG for thickness design?
We use both. For most municipal and commercial projects, the PCA method supplemented by AASHTO 1993 is sufficient and cost-effective. For high-ESAL corridors or when the owner requires a performance-based warranty, we switch to MEPDG inputs using climatic data from the McKinney National Airport weather station.
What type of concrete mix do you specify for McKinney pavements?
We default to a TxDOT Class P mix with a maximum water-cement ratio of 0.45 and minimum 28-day flexural strength of 570 psi. For industrial yards or heavy truck lanes, we may push the flexural strength target to 650 psi and require a limestone coarse aggregate to reduce the thermal expansion coefficient.
How quickly can you turn around a rigid pavement design after the field investigation?
Once the borings are complete and the lab results are in, the pavement design report—including thickness calculations, joint layout, and subbase specification—is typically delivered in 10 to 14 business days.