Development of an accelerated durability assessment procedure for high modulus base (HMB) materials

Title: Development of an accelerated durability assessment procedure for high modulus base (HMB) materials
Author(s): G. D. Airey, R. C. Elliott
Paper category : conference
Book title: Sixth International RILEM Symposium on Performance Testing and Evaluation of Bituminous Materials
Editor(s): M. N. Partl
Print-ISBN: 2-912143-35-7
e-ISBN: 2912143772
Publisher: RILEM Publications SARL
Publication year: 2003
Pages: 160 - 166
Total Pages: 7
Nb references: 15
Language: English

Abstract: There has been a general trend in the UK to use progressively stiffer roadbase materials, due to their expected "long life" performance. However, recent concerns over the dura-bility of these materials has led the UK Highways Agency (HA) to temporarily suspend the use of 15 and 25 penetration grade bitumen and establish a research programme to investigate the long-term durability of High Modulus Base (HMB) material. This paper describes the development and initial results of a high pressure, moisture/ageing test procedure that has been used to assess the durability of HMB materials. The procedure, which is performed on 100 mm diameter cores, has been successfully used to distinguish differences in durability among binders and aggregate types. Early results indicate vast differences in durability (retained stiffness modulus) performance between limestone and granite aggregate and minor differences between 15 penetration grade bitumens. Tests on the recovered binder from asphalt mixtures that have been subjected to satu-rated pressure ageing have shown comparable rheological properties to those obtained for standard pressure aged binders. Any loss of stiffness modulus or strength for the moisture aged asphalt mixtures can therefore be attributed to a loss of the cohesive and/or adhesive properties of the mixture rather than any unexpected "softening" of the binder.

Online publication: 2003-03-02
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/2912143772.018