PRECISION OF BITUMINOUS BINDER RHEOLOGY TESTS IN THE 2nd RILEM ROUND ROBIN TEST

摘要

RILEM Technical Committee 182 PEB "Performance Testing and Evaluation of Bituminous Materials" organised the second round robin test on binder rheology. The round robin test consisted in measurements of binders properties in dynamic shear rheometer DSR (stiffness modulus and phase angle) and in bending beam rheometer BBR. Testing of four binders of significantly different rheological characteristics was performed: plain bitumen, two SBS ? modified binders (one low and one high modification) and one EVA - modified binder. All binders were tested under three conditions: original, RTFOT aged and RTFOT and long term aged (PAV or RCAT). The objectives of this round robin test were: 1. to evaluate precision of both rheology test methods, 2. to compare results of various dynamic rheometers (mainly DSR but other types were used as well), 3. to evaluate influence of short term and long term ageing on test precision, 4. to develop recommendations for binder testing procedures: stifmess modulus and phase angle in dynamic loading test and stifmess modulus and m-value in low temperature creep test The main conclusions of this round robin test were that: 1. Acceptable repeatability and reproducibility can be achieved with DSR and BBR-testing on all types of binders - plain and polymer-modified - also in all stages of ageing. 2. Better in-laboratory and inter-laboratory precision in the dynamic rheometer measurements is obtained if the test procedure is precisely defined and followed. With respect to mis, the AASHTO-TP5 method can be recommended as DSR test procedure. 3. The ASTM BBR-test method can be recommended as test procedure for BBR testing.