The metric S.I. system is used throughout. The basic unit of stress, and hence, modulus of elasticity and stiffness, is the Pascal (Pa) which is 1 N/m2. Multiples of this are used for convenience viz.: 1 MPa = 1 x 106 N/m2, 1 GPa = 1 x 109 N/m2. All strains are quoted in micro-strain, 1 micro-strain = 1 x 10-6 µm/m. In all cases, logarithmic terms are to base 10.
Most Falling Weight devices have a load pulse duration of about 25 ms. However, the KUAB falling weight deflectometers use a pulse duration of approx. 60 milliseconds. A conversion equation is provided to convert KUAB deflections to a pulse duration of to 25 ms.
In pavement evaluation surveys, the structural condition is deduced from Falling Weight Deflection response. The recorded deflections are converted into a pavement model to assess the dynamic pavement performance.
The structural thickness design of a flexible pavement is based on a calculating strains and stresses at critical points in the pavement structure. Pavers® allows a pavement engineer to define or use calibrated performance models and failure criteria for all pavement layers and subgrade in his pavement design projects. By adjusting pavement layer thicknesses until the allowable number of passes matches the forecasted number, a structural pavement design is made.
Pavers® enables the determination of a technical load carrying capacity expressed in terms of PCN or PCR of an airport pavement. The PCN and PCR nunmer can be based on a number of departures of a single aircraft or on a mix of traffic. The worked examples explain the method presented in CROW’s Guideline on PCN Assignment
Once the traffic on the terminal is assessed, the thickness of a cemented base for a container terminal pavement with concrete blocks can be determined quite easily.
Since the flexible and rigid models in Pavers have the same User Interface, a jointed rigid concrete pavement can be designed quite easily with the slab-on-grade model using the same traffic data as in the flexible design. This is one of the many features of Pavers®, and is unique in the design software for intermodal container terminal pavement.
Airport Pavement Design has never been so easy! The Pavers ® design module for rigid or flexible aircraft pavement thickness determination requires a designer to enter a number of input parameters and then returns a pavement thickness.
A summary list of the steps to follow in a thickness assessment of flexible pavement is explained in a worked example.
De berekening van een gebonden fundering was nog nooit zo eenvoudig! De rekenmethode sluit aan bij de SAG/VNC en vult de leemte van ASCON (alleen geschikt voor ongebonden funderingen) in.
Met Bound Base ™ wordt de laagdikte van een gebonden fundering bepaald. De benodigde dikte onder een elementen, asfalt of betonverharding hangt af van specifieke ontwerpcriteria:
- weerstand tegen herhaalde belasting (vermoeiing op basis van spanning en/of rek onderin de fundering & verbrijzeling aan de bovenzijde).
- een toevallig optredende zware last die tot plotselinge breuk leidt (éénmalige rek tot breuk).
- Reflectiescheurvorming bij asfaltverhardingen.
