Designing a concrete pavement for a distribution centre off the Athboy Road is a very different proposition from one near the River Boyne’s floodplain. Around the IDA Business Park the glacial tills are dense and consistent, which gives you a solid subgrade straight away. Down closer to the river the alluvial silts and soft clays can drop your CBR values sharply, and that changes the entire slab thickness calculation. Before we commit to a rigid pavement section we map the subgrade with test pits to pick up on any buried organic layers or pockets of softer material that the boreholes might miss. Navan’s underlying geology is mostly Dinantian limestone, but the overburden is what really governs the pavement design — and it varies a lot more than most people expect across the town.
A rigid pavement in Navan lives or dies by its subgrade drainage — soak the CBR samples and design for the wet season, not the dry.
Methodology and scope
Local considerations
Navan sits in the Boyne valley, and the climate here means the subgrade spends a good part of the year near saturation. A rigid pavement acts as a structural element that bridges softer spots, but if the support underneath isn’t uniform you get pumping at the joints and eventually faulting that wrecks the ride quality. We’ve seen it happen on rural access roads where the drainage details were skimped. The biggest risk on a local project is ignoring the variability of the tills and alluvium across the site — one corner of the slab might be on competent gravel while the other sits on a lens of lacustrine clay that consolidates slowly. Our approach is to tie the slab design directly to a geotechnical investigation that includes dynamic cone penetration and soaked CBR profiling, so the concrete thickness and reinforcement are matched to the actual subgrade stiffness rather than a textbook assumption.
Explanatory video
Applicable standards
I.S. EN 13877-1:2013 — Concrete pavements, TRL Report RR 87 — Rigid pavement design for roads, TR34 4th Edition — Concrete industrial ground floors, I.S. EN 1992-1-1 (Eurocode 2) — Concrete structures, NRA HD 26/06 — Pavement and foundation design
Associated technical services
Highway and street rigid pavement
Design of jointed plain concrete pavements for local roads and national routes around Navan, including tie-bar and dowel bar schedules, subbase specifications, and longitudinal joint detailing per NRA standards.
Industrial ground floor slabs
TR34-compliant slab design for warehouses, distribution centres, and manufacturing facilities. We model racking leg loads, reach truck wheel loads, and curling stresses to define slab thickness, joint layout, and reinforcement requirements.
Port and heavy-duty yard pavements
Rigid pavement sections for container yards, bus depots, and waste transfer stations where point loads and chemical exposure demand high-performance concrete mixes and solid joint sealing systems.
Typical parameters
Frequently asked questions
What is the typical rigid pavement design for a Navan warehouse floor with heavy racking?
For a typical distribution centre near Navan, the slab design depends on the racking leg loads and the VNA truck axle weights. On a CBR of 5% or better — common on the glacial tills around the IDA Park — we normally arrive at a 175 mm to 200 mm thick jointed plain concrete slab with dowelled contraction joints at 6 m centres and a 150 mm cement-bound granular subbase. The concrete is specified as C32/40 with a minimum 28-day flexural strength of 4.5 MPa. The actual thickness is confirmed by Westergaard analysis and TR34 back-calculation once the soaked CBR values are in.
How much does a rigid pavement design cost for a project in Navan?
The design fee for a rigid pavement in Navan typically falls between €1,940 and €5,180, depending on whether it is a single access road or a full industrial yard with multiple loading zones. The scope includes subgrade evaluation, soaked CBR testing, Westergaard or TR34 analysis, joint layout drawings, and a construction specification. Larger projects with variable ground conditions across the site tend toward the upper end of that range.
Why does the subgrade need to be tested if the concrete slab is 'rigid'?
A rigid pavement spreads loads through slab bending, but it still relies on uniform subgrade support. If one section of the slab sits on limestone till and another on soft alluvium — a common situation along the Boyne valley in Navan — the differential movement causes pumping and eventual joint faulting. We measure the modulus of subgrade reaction (k-value) and soaked CBR to ensure the slab design accounts for the weakest areas, not the best.
What joint spacing do you recommend for concrete pavements in Ireland?
For Irish climatic conditions, and specifically for Navan where winter saturation is common, we generally specify contraction joint spacing at 24 to 30 times the slab thickness for jointed plain concrete pavements. That usually works out to 4.5 m to 6.0 m centres for a 200 mm slab. The joints are dowelled to maintain load transfer, and we specify sealants compatible with the temperature range and potential exposure to de-icing salts on highway applications.