Requirements for aggregates to be used in SMA are catalogued in Chapter 5. When differences among densities of aggregates used for composing an SMA aggregate * 2.36 mm in the United States, 2.0 mm in Europe. [30] NMAS stands for nominal maximum aggregate size—a sieve one size larger than the first sieve retaining more than […]
Рубрика: Stone Matrix Asphalt. Theory and Practice
Afterword
A few years ago, at the beginning of the work on this book about SMA, I did not suppose it would take on such imposing proportions. Meanwhile, over the course of work on the publication, it turned out that the quantity of accessible materials on SMA was really spectacular, and the range of SMA-related subjects […]
Additional Tests of Asphalt Mixture Characteristics
The previous deliberations on FPC use a basic level applied to the standard EN 13108-21 regarding tests of the mixture composition. Meanwhile methods of testing other properties of an asphalt mixture are discussed in Annex D (and are very informative). Collected results should be declared and used to support the procedure of extended validation of […]
Control of Production Variability
The standard EN 13108-21 contains a second element of FPC—namely, the control of production variability. This control is applied through the determination of the running mean deviation from the target and is described in Item A.5 of the standard. It involves monitoring systematic trends at the production stages of asphalt mixtures to prevent permanent one-sided […]
Determination of Compliance of a Tested Sample with a Recipe
After extraction, the result of each sample is compared with admissible deviations on test sieves and soluble binder content. A mix may be regarded as compatible with a recipe when all its components are within admissible tolerances. Table 14.2 depicts an excerpt of Table A.1 of Annex A of the standard demonstrating admissible deviations from […]
Analysis of Mixture Composition
Each sample is subjected to extraction testing, resulting in a gradation of the aggregate mix and a content of soluble binder. The sieving operation should be conducted using a set of sieves as in Table 14.2. The standard stipulates testing the aggregate gradation through five sieves (plus possibly a sieve for oversize particles 1.4D). The […]
Control of Compliance with an SMA Mix Recipe
14.8.3.1 determination of the Operating compliance Level The principle of fixing frequencies of control testing depends on the number of deviations found and has been adopted in the standard EN 13108-21. With an established level of requirements (X, Y, or Z), the frequency of sampling is variable, depending on the production accuracy of the asphalt […]
G eneral Guidelines for a Control System of Production Homogeneity
The guidelines for controlling production homogeneity are made up of the following two parts: • Control of compliance with a recipe, accomplished by establishing an operation compliance level (OCL), which is a variable index that estimates the production accuracy and indicates the appropriate mixture test frequencies • Control of production variability through determining a running […]
FACTORY PRODUCTION CONTROL EN 13108-21
In the European system of standardization of asphalt mixtures according to the series of standards EN 13108, the issues of control and quality assurance have been deliberated in EN 13108-21:2006 Bituminous Mixtures—Material Specifications— Part 21: Factory Production Control (with Amendment AC/September 2008). This standard contains an outline of requirements regarding the system of quality assurance […]
EVALUATION OF CONFORMITY
Asphalt mixtures are construction products and the standards EN 13108-1 to 13108-7 are harmonized with the Construction Products Directive 89/106/EEC. The system “2+” has been adopted to evaluate conformity of asphalt mixtures. It consists of the following: • Initial type testing of each mix produced by its manufacturer • Certification of a Factory Production Control […]