Analytically designed - agreed by construction contract: asphalt pavements in the area of conflict between theory and reality

Abstract

In recent years, new construction contract (functional and concession) forms were developed in German. For these
types of contracts, but also for variant solutions under conventional tenders the possibility exists to abstain from a
standardized structure design according to the RStO (guideline) and instead make an individual design. Therefore
the guidelines for the analytical design of the construction of traffic areas with asphalt pavement have been
developed and announced. By using the method of analytical design the layer thicknesses of the asphalt construction
is primarily defined in dependence of the material properties of the used asphalts. To determine the required sizing
relevant asphalt properties, these are essentially fatigue and stiffness, additional material investigations are
necessary. The effort for these investigations significantly exceeds the effort for a initial type testing. When using a
standardized construction for asphalt pavements, it is sufficient to settle in the contractual settlement compositional
features and void content and compaction of the final layer and to check out during construction.
Prior to the contractual agreements two key questions must be answered: First, how the material properties change
in phase of initial testing in the laboratory, the production of the asphaltmixes and the effects of construction
(asphalt-paver, rollers). This question was investigated in research-projects in which parallel to the classical contract
management the required investigations have been made. The previous evaluations provide clues as to what asphalt
properties do not change much, or where relatively safe can be inferred from the results of the initial type testing of
the expected outcome of the built-layer and in which properties of this connection is not as stringent.
The second question concerns the nature and extent of tests, which are necessary to check out the construction work.
The procedure according to the ZTV-Asphalt (guideline) requires a test check each 6.000 m² produced surface. Due
to the large number of cores to be removed and to be tested (about 15 per section) this procedure is not practicable
and would already result to a variety of weaknesses in the new construction. In order to find a workable and
mutually acceptable solution, possible solutions are considered in various research-projects. One of these
possibilities to check out the performed construction work shall be presented in the paper and the results are
discussed. The defined test grid in the ZTV-Asphalt (site-specific assessment criteria) will be maintained. However
the full extent of testing to determine the design relevant properties of asphalt was not carried out for each field of
test grid. Rather a reasonable allocation of the required number of asphalt tests to be carried out was made on
several sections (and at one point the entire scope of investigation was carried out). In combination of all test results
so there can be an assessment of the construction work in relation to the underlying design. This represents a
reduction of investigation costs, labor and time effort but also less damage to the asphalt layers newly produced
while maintaining the same quality analyzes of the obtained results.

Original document

The different versions of the original document can be found in:

• https://zenodo.org/record/1485100 under the license http://creativecommons.org/licenses/by-nc-nd/4.0/legalcode

• https://zenodo.org/record/1485100,

http://dx.doi.org/10.5281/zenodo.1485099 under the license http://creativecommons.org/licenses/by-nc-nd/4.0/legalcode

• https://zenodo.org/record/1485100,

http://dx.doi.org/10.5281/zenodo.1485100 under the license http://creativecommons.org/licenses/by-nc-nd/4.0/legalcode

DOIS: 10.5281/zenodo.1485099 10.5281/zenodo.1485100