Effect of Iterlene adhesion promoters on pavement bitumen properties

Abstract

Problem. Moisture is one of the most important factors of impact on asphalt quality. Water strips bitumen films from the mineral material surface. This process causes peeling on the pavement surface that leads to potholes appearing and a pavement disintegration as a result. The low adhesion between bitumen binder and mineral surface is a key factor of this process. The most common way to increase adhesion is modification of bitumen with adhesion promoters (antistripping agents) which are presented in a wide range of varieties that expands as the volume of their use in road industry grows. Goal. The goal of this research is to estimate the effect of the Iterlene additives of various chemical compositions (amine, polyphosphoric and silane) on pavement bitumen properties. Methodology. The commonly used in Ukraine’s road industry bitumen BND 70/100 is used for modification with two concentrations of Iterlene IN/400-L Green, Iterlene PE-31 and Iterlene SL/100-Plus. The quality of obtained binders is estimated with actual national standard DSTU 4044 and SOU 45.2-00018112-067. Results. With the obtained data it is found that adhesion promoters Iterlene have almost no influence on the standard qualitative indices of bitumen. Meanwhile the chosen additives change bitumen adhesion to various degrees. The most effective in this way is the additive of silane type Iterlene SL/100-Plus. Its minimal required concentration raises adhesion value up to 97 %. The less effective is the amine type of additive Iterlene IN/400-L Green. Its maximal required concentration leads to adhesion increasing up to 85 % only. Originality. In this research work the evaluation is performed of the thermal stability of the Iterlene additives of various chemical types on the adhesion changing after hardening by RTFOT and TFOT methods. It was found that adhesion of bitumen with Iterlene IN/400-L Green additive after hardening by both methods returns to initial values of adhesion of non-modified bitumen. The highest thermal stability is inhered for Iterlene SL/100-Plus additive. For the bitumen with maximal required concentration of this additive the adhesion value after hardening by both TFOT and RTFOT methods does not change at all. Practical value. By the results of the Rolling Bottle Test, it was found that 70 – 80 % of granite surface stays covered with binder modified by Iterlene SL/100-Plus after 24 hours of test time. Meanwhile this adhesion promoter does not (or almost does not) increase adhesion in the case of limestone grains in this test.