A laboratory study of the effect of fiberglass additive on the behavioural properties of rap asphalt mixtures

The increase in the amount of reclaimed asphalt pavement (RAP) and environmental concerns for bitumen production have contributed to the use of RAP in road construction and maintenance. The use of higher than 15% of RAP adversely affects the physical and rheological properties of the asphalt binder and the mechanical properties of mixtures. Therefore, the use of bitumen and asphalt mixture improver were necessary to reduce the negative effects generated with the use of RAP. This paper aims to study the effect of fiberglass (FG) (0.5%, 1.0%, 1.5%, and 2%) on the mechanical properties of asphalt concrete containing 25%, 50% RAP and 9% waste engine oil. The performance of RAP asphalt mixtures incorporated with FG was evaluated using the Marshall stability test, moisture susceptibility test, and immersion wheel rutting test. The results indicated that the use of FG and RAP materials to rejuvenated asphalt mixtures resulted in an increase in the values of Marshall stability and rutting resistance. Moreover, the study revealed that increasing the content of RAP material and FG results in increased resistance of asphalt to moisture damage. This paper concluded that using 0.15% of FG and 50% RAP materials gives the best results

Evaluating the performance of reclaimed asphalt pavement incorporating pelletrap as a rejuvenator

In the recent years, the use of reclaimed asphalt pavement (RAP) in the pavement has become inevitable for economic and environmental reasons. However, the brittleness property of aged asphalt in the RAP restrict its usage in a high percentage. Nevertheless, the rejuvenators are introduced into the mixtures to reverse the effect of ageing processes, decrease the stiffness and increase the workability of RAP mixture. In the present research, various percentages of PelletRAP rejuvenator were added to 100% of RAP mixtures. The performance characteristics of rejuvenated mixtures were investigated via resilient modulus (MR), dynamic creep, and wheel tracking tests. The results showed that when the PelletRAP was included into the mixture, the MR values and the creep stiffness modulus (CSM) decreased, while the permanent creep, the creep strain slope (CSS) and the rutting depth increased. However, all the rejuvenated mixtures exhibited better results than that of virgin mixture. Such a trend of findings suggested that PelletRAP can be used as a rejuvenator without a negative effect on the high-temperature performance of asphalt mixtures

The influence of PelletRAP™ rejuvenator on the mechanical properties of reclaimed asphalt pavement

In the last decade, the use of reclaimed asphalt pavement (RAP) resulted from asphalt milling process has been widely increased for economic and environmental reasons. However, RAP mixtures have undesired characteristics, such as higher stiffness and low flexibility. In this case, the rejuvenators should be used for restoring the properties of RAP which were lost during service life. In the present research, the mechanical properties of 100% RAP incorporating various percentages of PelletRAP™ rejuvenator were evaluated via stability, flow, stiffness, indirect tensile strength (ITS), moisture damage and Cantabro loss measurements. The results showed that the rejuvenated mixtures containing 4% of PelletRAP™ exhibited better performance in terms of stability, cracking and moisture damage resistance, as well as durability, compared with virgin mixtures. Thus, it can be concluded that 100% RAP can be renovated and re-used in the pavement if it is mixed with an appropriate prescription of PelletRAP™. The proposed of incorporating PelletRAP™ with RAP is beneficial in the improvement of sustainability and cost-efficiency of the asphalt mixtures industry

A comparative assessment of the physical and microstructural properties of waste garnet generated from automated and manual blasting process

Cold mix asphalt (CMA) is an eco-friendly sustainable asphalt mixture, mostly for asphalt surface treatments (ASTs). However, material compatibility and poor adhesion leading to high voids, moisture damage susceptibility, and weak early strength remain challenging. Efforts to solve this limitation is beamed towards binder improvement and modification with modifiers, adhesion promoters, or polymers. Other forms of AST mixture improvement entail supplementary cementitious reinforcing or pozzolanic agents in the form of by-products. In this study, the physio-mechanical and microstructural desirability of spent garnet for use as fine aggregate in CMA was explored. Spent garnet is a by-product of abrasive blasting, often produced in large quantities and disposed of in landfills. Often, spent garnet waste gets contaminated with toxic elements either during usage or in landfills. This study aimed to investigate the properties of Automatically (AG) and Manually generated (MG) spent garnet grades. The physio-mechanical, morphologic, and chemical parameters of spent garnet were assessed to achieve this aim. The result compared with relevant specifications on cold mixtures plus Jabatan Kerja Raya (JKR) requirement. Moreover, crystallinity and composition were studied using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and X-ray Fluorescence (XRF). The presence of toxic heavy metals that often contaminate spent garnet deposits in landfills was evaluated too. Results suggested that both AG and MG's high sand equivalent and least water absorption of 98 %, 89 %, and 0.14 %, 0.23 % accordingly, and can replace sand in CMA. However, MG spent garnet is not desirable for chemically sensitive materials. The AG garnet was found to be Pyrope while the MG spent garnet is largely Almandine garnet – the strongest form of garnet, including traces of other garnet forms

Effect of polymer-modified bitumen and reclaimed asphalt pavement on the physical properties of bitumen

The high cost of road construction due to the energy required for new material production and the environmental impact necessitates the use of reclaimed asphalt pavement (RAP) and other waste materials. This paper examined the effect of using RAP with a PET additive as a rejuvenator. PET additive (2%) was added to the virgin binder (VB) of 60/70 penetration grade to form a Polymer modified bitumen (PMB). RAP percentages used were 30, 40, and 50%, respectively. The physical properties were examined using the penetration, softening point, and ductility. The results show that the physical properties of RAP were improved by utilizing Rap binder (RB) and PMB mix ratio. The penetration and ductility values increased by 46.4% and 66.7%, respectively, with the PMB (30): RB (70) ratio blend, compared to RB: VB blend. This suggests a reduction in brittle behavior and less stiffness with the addition of PMB in the blend, enhancing the flexibility of the RAP. Although both mixtures blended with RB exhibited softening points within the acceptable range, improved performance was observed with RB/PMB mix blend over RB/VB blend when used in hot asphalt mixtur

Effect of polymer-modified bitumen and reclaimed asphalt pavement on the physical properties of bitumen

The high cost of road construction due to the energy required for new material production and the environmental impact necessitates the use of reclaimed asphalt pavement (RAP) and other waste materials. This paper examined the effect of using RAP with a PET additive as a rejuvenator. PET additive (2%) was added to the virgin binder (VB) of 60/70 penetration grade to form a Polymer modified bitumen (PMB). RAP percentages used were 30, 40, and 50%, respectively. The physical properties were examined using the penetration, softening point, and ductility. The results show that the physical properties of RAP were improved by utilizing Rap binder (RB) and PMB mix ratio. The penetration and ductility values increased by 46.4% and 66.7%, respectively, with the PMB (30): RB (70) ratio blend, compared to RB: VB blend. This suggests a reduction in brittle behavior and less stiffness with the addition of PMB in the blend, enhancing the flexibility of the RAP. Although both mixtures blended with RB exhibited softening points within the acceptable range, improved performance was observed with RB/PMB mix blend over RB/VB blend when used in hot asphalt mixtur

Effect of Polymer-Modified Bitumen and Reclaimed Asphalt Pavement on The Physical Properties of Bitumen

The high cost of road construction due to the energy required for new material production and the environmental impact necessitates the use of reclaimed asphalt pavement (RAP) and other waste materials. This paper examined the effect of using RAP with a PET additive as a rejuvenator. PET additive (2%) was added to the virgin binder (VB) of 60/70 penetration grade to form a Polymer modified bitumen (PMB). RAP percentages used were 30, 40, and 50%, respectively. The physical properties were examined using the penetration, softening point, and ductility. The results show that the physical properties of RAP were improved by utilizing Rap binder (RB) and PMB mix ratio. The penetration and ductility values increased by 46.4% and 66.7%, respectively, with the PMB (30): RB (70) ratio blend, compared to RB: VB blend. This suggests a reduction in brittle behavior and less stiffness with the addition of PMB in the blend, enhancing the flexibility of the RAP. Although both mixtures blended with RB exhibited softening points within the acceptable range, improved performance was observed with RB/PMB mix blend over RB/VB blend when used in hot asphalt mixture

SPARC 2018 Internationalisation and collaboration : Salford postgraduate annual research conference book of abstracts

Welcome to the Book of Abstracts for the 2018 SPARC conference. This year we not only celebrate the work of our PGRs but also the launch of our Doctoral School, which makes this year’s conference extra special. Once again we have received a tremendous contribution from our postgraduate research community; with over 100 presenters, the conference truly showcases a vibrant PGR community at Salford. These abstracts provide a taster of the research strengths of their works, and provide delegates with a reference point for networking and initiating critical debate. With such wide-ranging topics being showcased, we encourage you to take up this great opportunity to engage with researchers working in different subject areas from your own. To meet global challenges, high impact research inevitably requires interdisciplinary collaboration. This is recognised by all major research funders. Therefore engaging with the work of others and forging collaborations across subject areas is an essential skill for the next generation of researchers

17-allyamino-17-demethoxygeldanamycin treatment results in a magnetic resonance spectroscopy-detectable elevation in choline-containing metabolites associated with increased expression of choline transporter SLC44A1 and phospholipase A2

Abstract Introduction 17-allyamino-17-demethoxygeldanamycin (17-AAG), a small molecule inhibitor of Hsp90, is currently in clinical trials in breast cancer. However, 17-AAG treatment often results in inhibition of tumor growth rather than shrinkage, making detection of response a challenge. Magnetic resonance spectroscopy (MRS) and spectroscopic imaging (MRSI) are noninvasive imaging methods than can be used to monitor metabolic biomarkers of drug-target modulation. This study set out to examine the MRS-detectable metabolic consequences of Hsp90 inhibition in a breast cancer model. Methods MCF-7 breast cancer cells were investigated, and MRS studies were performed both on live cells and on cell extracts. 31P and 1H MRS were used to determine total cellular metabolite concentrations and 13C MRS was used to probe the metabolism of [1,2-13C]-choline. To explain the MRS metabolic findings, microarray and RT-PCR were used to analyze gene expression, and in vitro activity assays were performed to determine changes in enzymatic activity following 17-AAG treatment. Results Treatment of MCF-7 cells with 17-AAG for 48 hours caused a significant increase in intracellular levels of choline (to 266 ± 18% of control, P = 0.05) and phosphocholine (PC; to 181 ± 10% of control, P = 0.001) associated with an increase in expression of choline transporter SLC44A1 and an elevation in the de novo synthesis of PC. We also detected an increase in intracellular levels of glycerophosphocholine (GPC; to 176 ± 38% of control, P = 0.03) associated with an increase in PLA2 expression and activity. Conclusions This study determined that in the MCF-7 breast cancer model inhibition of Hsp90 by 17-AAG results in a significant MRS-detectable increase in choline, PC and GPC, which is likely due to an increase in choline transport into the cell and phospholipase activation. 1H MRSI can be used in the clinical setting to detect levels of total choline-containing metabolite (t-Cho, composed of intracellular choline, PC and GPC). As Hsp90 inhibitors enter routine clinical use, t-Cho could thus provide an easily detectable, noninvasive metabolic biomarker of Hsp90 inhibition in breast cancer patients