Laboratory Investigation of Lignocellulosic Biomass as Performance Improver for Bituminous Materials

Lignocellulosic biomass has gained increasing attention as a performance modifier for bituminous material due to the vast amount available, its low cost and its potential to improve the durability of pavement. However, a comprehensive study concerning both the binder and mixture performance of modified bituminous material with lignocellulose is still limited. This research aims to evaluate the feasibility of applying lignocellulose as bitumen modifier by rheological, chemical and mechanical tests. To this end, two lignocellulosic biomass modified bituminous binders and corresponding mixtures were prepared and tested. The chemical characterization revealed the interaction between lignocellulosic biomass and bitumen fractions. Rheological test results have shown that lignocellulosic modifiers improve the overall performance of bituminous binder at high, intermediate and low temperatures. The findings obtained by mixture mechanical tests were identical to the binder test results, proving the positive effect of lignocellulosic biomass on overall paving performance of bituminous materials. Although lignocellulosic modifier slightly deteriorates the bitumen workability, the modified bitumen still meets the viscosity requirements mentioned in Superpave specification. This paper suggests that lignocellulosic biomass is a promising modifier for bituminous materials with both engineering and economic merits. Future study will focus on field validation and life cycle assessment of bituminous pavement with lignocellulosic biomass.

AIR POLLUTION AND THE FILTRATION PROCESSING SYSTEMS FOR THE BITUMINOUS MATERIAL PLANTS

It is known that particulate matters of different granulations are one of the most important air and environmental pollutants, in general. This paper presents a prototype system for filtering particulate matter from extinguishing gases of a bitumen preparation plant using a "jet pulse" method for filter bags cleaning. For such type of filter plant, due to technological reasons, there is the need to create a shock wave which is required for the cleaning of the filter bags. The shock wave is generated by electromagnetic valves, whereas the tactile of the valve is determined by special controller depending on the type of filter, bags and air pollution. The result obtained through the use of special types of controllers allows the life span of the electric fan and the prevention of their overheating and damage.

Bituminos Insulations Durability of Underground Metallic Pipelines II. Laboratory study on the aging of bituminous material

The structural and physicochemical changes that lead to the aging of the bituminous insulation of underground metallic pipelines were determined through various investigations (XRD, dielectric spectroscopy and thermal analysis � coupled techniques TG + DTA + DTG). The resistance to moulds of the bituminous insulation was evaluated by using specific microbiological methods and the dominant microbiological species found in the soil where the investigated bituminous material was exposed for 19 years were identified. The measurements carried out on samples taken from site showed that the bituminous material used in the anti-corrosive isolation of steel pipes has a very low resistance to microorganisms; thus, the dielectric qualities of bitumen deteriorate substantially (tg� increases 3-4 times). The exposure of the bituminous insulation to different climatic conditions and to solar radiation (UV-IR) leads to a decrease in the dielectric losses in the insulation and to an increase in crystallinity and thermo oxidative reactivity of bitumen, thus leading to a significant decrease in the material�s resistance to the action of fungi.