Formulating Highway Paving Asphalts from the Vacuum Residue of a Paraffinic Crude

Many specifications of paving asphalts are closely related to their colloidal stability, which is, however, determined by their exact chemical compositions. The Yumen vacuum residue (YVR), the bottoms of a paraffinic crude oil is unfit for the production of highway paving asphalts directly, Neither are the de-oiled asphalts of the YVR. In this research a blending method and an optimal process of solvent de-asphalts are adopted to investigate the feasibility of formulating highway-paving asphalts from YVR. Results show that highway paving asphalts are formulated by blending solvent de-oiled asphalts with one or more of the materials including YVR, decanted oil from FCC process, and furfural extracts from lubricating base stocks. Further investigations indicate that adding oil decanted from FCC process to the solvent de-asphalting process can increase the de-asphalted oil production, improve the de-oiled asphalts quality, and thus optimize the refinery processes. The methodology of this research can be extended even to refineries processing non-paraffinic crude oils.

Modification of FCC slurry oil and deoiled asphalt for making high-grade paving asphalt

With the rapid development of modern industry,high-grade paving asphalt is massively required to meet the demands for modern transportation.As one of additives,natural asphalt is indispensable since it can improve the performance of paving asphalt in all aspects.However,the application of non-renewable natural asphalt is increasingly restricted by its limited reserves.It is imperative to find alternative approaches to produce high-grade paving asphalt.Fluid catalytic cracking(FCC)slurry oil is an ideal soft component for producing paving asphalt due to its high content of aromatics and resins.However,its bad ageing resistance limits its application to only low-grade paving asphalt.In the present work,a novel approach for producing high-grade paving asphalt was investigated using chemically modified FCC slurry oil and deoiled asphalt(DOA).The FT-IR and NMR results showed that dehydrogenation and condensation reaction occurred during the ageing process.From a series of aliphatic alcohols and aldehydes,propanal was selected as a proper modifier to improve the ageing resistance of FCC slurry oil.The propanalmodified slurry oil possessed more substituted aromatic units and less aromatic hydrogen atoms than other modified slurry oils,thus showing better ageing resistance.With the increase of length of aliphatic chains in modifier,the modified slurry oil contained more and longer alkyl substituent group on aromatics.Compared with the cross-linked oil(slurry oil modified by cross-linking agent),modified slurry oil possessed similar ageing resistance but higher flowing ability.Also,the effect of operation conditions on the kinematic viscosity of modified slurry oil were investigated.Blended with modified slurry oil,the penetration ratio of asphalt product increased from 53.7 to 66.2,which met the standard of 70#paving asphalt.Both the microscopic observations and FT-IR results indicated that modification process effectively reduced the oxidation degree of asphalt product,thus increasing the ageing resistance.Consequently,with aid of this process,high-grade paving asphalt was readily produced from low value oil from downstream products of refinery,instead of the depleting natural asphalt.

Progression of e-ticketing implementation for state transportation agencies for asphalt materials

E-ticketing,which has been promoted by the Federal Highway Administration(FHWA)“every day counts”(EDC)initiative,utilizes software applications to digitally track and store information regarding highway construction materials paid by state transportation agencies(STAs)by weight in unit bid contract structures.STAs often face implementation barriers such as institutional inertia,or the resistance by stakeholders to adopt changes from the status quo,including new technologies.The purpose of this paper is to determine the progression of STA e-ticketing policy adoption,specifically with a focus on asphalt paving operations,due to the COVID-19 pandemic.To accomplish this research effort,previous FHWA data,National Cooperative Highway Research Program(NCHRP)data,and other literatures are reviewed to determine an implementation baseline.Additional data is collected from the American Association of State Highway and Transportation Officials Committee on Con-struction to gain current feedback from STAs and their highway contractor partners after the COVID-19 pandemic.Additionally,a case study featuring the Kentucky Transportation Cabinet(KYTC),the Kentucky Association of Highway Contractors(KAHC),and the Plantmix Asphalt Industry of Kentucky(PAIKY)is performed to provide more in-depth analysis.The major finding includes a statistically significant result indicating increased imple-mentation of e-ticketing for asphalt operations within the last two years,along with noting benefits including employee safety,task loading,and project documentation along with concerns regarding cellular connectivity and procurement responsibilities.These findings indicate the importance of STAs investing in partnership with con-tractors to improve stakeholder buy-in before proceeding towards e-ticketing adoption.

Preparation of low-cost waterproofing materials

To address the need for producing a cheap,single-component,hot-applied compound joint sealant with high quality for sealing joints and cracks in concrete and flexible pavements without using primer for installation,a hot-applied modified asphalt sealant was produced by blending up about 30% starch into 20% citric acid.The starch and the asphalt cement were mixed at a temperature of above 160 ℃.Thus the waterproofing asphalt was manufactured to protect the surface of various shapes and types from water leakage using the citric acid.Results indicate that this sealant complies with the requirements of ASTM D-1191,D-6690-06a and D-7116-05.The citric acid is a kind of reliable materials for asphalt cement,which can be widely used in paving and waterproofing construction materials,and this offers profound engineering and economic advantages.