Bituminous Slurries Research Articles

Study on the influence of spent-catalysts microphysical properties on FCC/asphalt interface interaction

Abstract This research aims to quantify the interfacial interaction mechanism between the fluid catalytic cracking (FCC) spent catalyst and asphalt. The two types of spent-catalysts, three types of mineral powders, and their bituminous slurries are selected to complete the tests of microscopic morphological, specific surface area, surface energy, fourier transform infrared spectroscopy, specific adhesion work, and interaction parameter C-value for FCC-spent-catalysts in laboratory. The results indicate that: (1), the physical properties of FCC-spent-catalyst compared with mineral powder when the particle size ranging from −2.2 to 5.4 μm between FCC-spent-catalysts and mineral powder, the specific surface area of FCC-spent-catalyst was 100 to 900 fold that of mineral powder, while the alkali value of FCC-spent-catalysts was 2 to 8 fold that of mineral powder; no significant difference was observed in surface energy; (2), the mixture system did not produce new functional groups after FCC-spent-catalyst addition to the asphalt mixture system; (3), the adhesion work of FCC-spent-catalyst was close to that of mineral powder, the specific adhesion work was 74 to 763 fold that of mineral powder when they have the similar particle size; (4), the interaction parameter C-value between FCC-spent-catalyst and asphalt was higher than the interaction between mineral powder and asphalt at identical test temperatures. This study demonstrates that the FCC-spent-catalyst have the potential to improve the in-service performance of the pavement under high-temperature and moisture damage in terms of a larger specific surface area and stronger.

Repair of a minor bridge in the state of failure with an atypical design using prestressed bridge meshes and bitumen slurry

This article discusses methodological approaches to the repair and maintenance of minor bridges with the atypical design that are in the state of failure, that doesn’t have design documentation, as well as regulatory and methodological documents for the maintenance work organization and technology. Such bridges, although in small numbers, are present on territorial and municipal road networks, for example, in the Orenburg region. The bridge floor turned out to be hydrophobic. Precipitation cannot penetrate under the asphalt concrete layer due to the loosened bitumen presence, meanwhile, the water that was under the asphalt concrete layer during the summer month came out through the asphalt concrete layer pores through pore pressure. A month after the emergency repair work, under the influence of high summer temperature and mechanical load from passing vehicles, the consolidation processes associated with the evaporation of water were completed, and the loosened bitumen turned into a film state. In the limit of a cold wet asphalt mix based on dispersed viscous bitumen, the conventional hot asphalt concretes properties are achieved. Setting smooth, durable, and waterproof coating allows for minimizing the passing traffic dynamic effects, significantly slowing down the destructive processes in the bridge’s bearing elements. For the first time, a minor bridge in the state of failure with an atypical design was repaired by grouting the soil ground around the bridge supports with a liquefied bitumen slurry to a 0.5 m depth, which made it possible to ensure its equal strength. At the same time, the dispersion degree for this project was 1–10 microns due to the bituminous slurry preparation specifics. New is the setting of a hydrophobic double-layered bridge floor without a waterproofing layer from a cold wet asphalt concrete mixture based on dispersed viscous bitumen and the use of a bridge mesh. The possibility of using bitumen-cement-concrete nonshrinking mixtures in the repair of the bridge masonry is shown. The bridge floor geometry was selected for the shockless mode of the existing traffic flow, with the account of the velocity squared of traffic, the bridge floor height, the sum of curvature radii, and the vehicle wheel. The possibility of using bitumen-cement-concrete non-shrinking mixtures in the repair of the masonry of a bridge structure is shown. A new result is also the reinforcing system construction for a bridge floor made of cold wet asphalt concrete based on prestressing of a metal bridge mesh that is flexible with tension in displacement increments.

Slurry surfacing: a review of definitions, descriptions and current practices

Cold bitumen emulsions (CBE) are currently used worldwide for both non-structural (cold surface treatments) and structural (cold bituminous mixtures) paving applications. Among non-structural applications, bituminous slurry surfacings (BSS) allow to improve surface properties and extend the pavement’s life. However, selection of constituents, mix design, application and quality control procedures for BSS are mostly based on local experience and empirical tests. Thus, the use of BSS is associated to higher technical risks with respect to the use of traditional hot-mix technologies.
 In this context the RILEM Technical Committee 280-CBE TG2 “Multiphase characterisation of cold bitumen emulsion materials” aims to collect worldwide theoretical knowledge and experiences on BSS and to inspire new standards, specifications and guidelines encompassing the wide set of existing practices. This paper summarizes the first part of the literature review carried out as part of the TC workplan and focuses on the definition, the description and the application method for BSS. National standards, construction specifications and best practice documents from North America, South America, Europe and Australia are analysed and compared.

Noise Reduction Properties of an Experimental Bituminous Slurry with Crumb Rubber Incorporated by the Dry Process

Nowadays, cold technology for asphalt pavement in the field of road construction is considered as an alternative solution to conventional procedures from both an economic and environmental point of view. Among these techniques, bituminous slurry surfacing is obtaining an important role due to the properties of the obtained wearing course. The functional performance of this type of surfaces is directly related to its rough texture. Nevertheless, this parameter has a significant influence on the tire/road noise generation. To reduce this undesirable effect on the sound performance, new designs of elastic bituminous slurries have been developed. Within the FENIX project, this work presents the acoustical characterization of an experimental bituminous slurry with crumb rubber from wasted automobile tires incorporated by the dry process. The obtained results show that, under controlled operational parameters, the close proximity sound levels associated to the experimental slurry are considerably lower than those emitted by a conventional slurry wearing course. However, after one year of supporting traffic loads and different weather conditions, the evaluated bituminous slurry, although it conserves the original noise reduction properties in relation to the conventional one, noticeably increases the generated sound emission. Therefore, it is required to continue improving the design of experimental surfaces in order to enhance its long-term performance.

Developing anthracite coal water slurry fuel

Abstract : Public law has directed the Department of Defense (DOD) to increase the use of coal, particularly anthracite, at steam generating facilities. This study evaluates the feasibility of producing slurry fuel from anthracite coal and examines the combustion characteristics of the anthracite/water fuel slurry. The T-Process, a proprietary process developed by Otisca Industries, Ltd., Syracuse, NY, was used to produce anthracite-based coal water slurries for testing and combustion. Although it is feasible to manufacture anthracite water fuel, the slurries used in this research would not bum well without substantial amounts of natural gas cofiring. Stable combustion with reduced support fuel can probably be achieved by chemically or physically modifying the factors that affect combustion. Additional research to determine the differences between anthracite and bituminous slurries, to increase the residence time for anthracite slurries, and to manufacture slurries with oil rather than water needs to be conducted to help the DOD meet anthracite purchase/consumption targets.