Rutting assessment of crumb rubber modifier modified warm mix asphalt incorporating warm asphalt additive

Warm Mix Asphalt (WMA) as a green technology, permits production of asphalt mixtures at lower temperatures compared to conventional HMA; emissions and energy consumption reduction, were among the key success of this technology, thus, enhancing social, economic, and environmental sustainability. But due to the reduced production temperature, WMA are more prone to rutting, to improve the rutting resistance of WMA mixtures and minimize pollution resulting from waste rubber tire. Therefore, the effect of wet processed Crumb Rubber Modifier (CRM) on rutting depth of WMA mixtures incorporating 2.5% Sasobit by weight of base binders were assessed in the laboratory. In this study, the asphalt mixtures were fabricated in accordance with Superpave, using; crush granite aggregate of 9.5mm NMAS and the four binders that were produced by blending the PG 64 binder with different contents of 40 mesh size CRM (0%, 5%, 10%, and 15%, by weight of the base binder). Rutting depths of the mixtures were assessed on 150mm diameter and 70mm thick cylindrical samples using wheel tracker, the wheel tracking test were carried out at 45oC and 60oC, in accordance with BS 598 Part 110 (1998). Based on the results of wheel tracking tests, CRM could improve the resistance of the WMA mixtures to rutting. It was also found from statistical Analysis of Variance (ANOVA), that the two influence factors; CRM, and the test temperature both having p-values less than the assumed significance at 95% confidence level, therefore they have significant effect on rutting in WMA

Diverse sustainable materials for the treatment of petroleum sludge and remediation of contaminated sites : a review

Activities in the petroleum industry unavoidably generates huge amount of petroleum sludge that contain hazardous constituents. Numerous treatment techniques are proven to reduce toxicity, sludge volume, and extract petroleum products. Their efficiency is determined by the sludge properties. These treatment technologies can lessen the hazardous elements in sludge and alleviate their negative environmental and human health impacts. However, only a few, can strike a compromise between meeting strict environmental regulations and consuming notable quantity of water, energy, and chemicals. Now, there are no waste-free and cost-effective technologies available for petroleum sludge treatment. Therefore, this review was designed to highlight the several waste, plants, and other materials that have been utilized during petroleum sludge or petroleum contaminated site treatment for resource recovery and to ensure environmental safety. The application of various additives to remediate petroleum sludge contaminated areas has been proven to be a practical and environmentally beneficial alternative. The review found that reusing remediated soils for bioremediation activity on soil contaminated with oil sludge was efficient. The review further revealed that phytoremediation by sowing plants in the soil can remarkably boost microorganism's growth and TPH elimination rate. Also, in planted treatments using Zea mays L., Secale cereale L., Festuca arundinacea, Onobrychis viciifolia, Vertiver zizanioide, Cajanus cajan, Medicago sativa, Lolium perenne, Ttrifolium pratense etc. the most probable number were significantly higher than in unplanted treatments. It was also discovered that there is a commercial potential for the use of plants as sources of biosurfactant for use in accelerated TPHs degradation. Biosurfactant supplementation in the phytoremediation of metals and petroleum hydrocarbons co-contaminated soil was effective. The review suggests the use of composite materials for petroleum sludge treatment