We still see contractors in Celbridge assuming a 150 mm lean mix will fix everything. It won't. The Liffey floodplain silts along the R403 approach shift more than you'd expect, and without a proper CBR road test to calibrate the subgrade modulus, even a 250 mm unreinforced slab can curl and crack within two winters. Our team approaches rigid pavement design from the bottom up: we start with the soil, not the concrete. By combining the plate-bearing derived k-value with a realistic Westergaard edge-loading model, we size joint spacing and dowel bars that actually match what's under the slab. For the heavy truck traffic turning into the industrial estates off the M4 link, this difference isn't academic, it's the margin between a floor that serves twenty years and one that spalls after five. We run our own lab, so the numbers you get come from the same people who pulled the cores.
A rigid pavement's performance is decided in the first 300 mm below the slab, not in the concrete specification printed on the office wall.
