THE EFFECT OF DISSOLVED PLASTIC POLYMER MODIFICATION ON RUTTING AND FATIGUE RESISTANCE PROPERTIES OF WARM BITUMEN BLEND

Recently, large amounts of waste polymers are being generated in Nigeria. One of the waste polymers is plastic bottles. Hot Mix Asphalt (HMA) are produced at high temperatures with high energy consumption and environmental hazard. The purpose of using Warm Mix Asphalt (WMA) is to reduce the production and laying temperature and emission of greenhouse gases. Therefore, this research investigated the effect of Dissolved Plastic Bottle (DPB) on the rheological, rutting and fatigue resistance properties of warm bitumen blend thereby reducing the environmental hazard associated with the Waste Plastic Bottles (WPB) disposal and consequently improving pavement service life. WPB was obtained from different waste generation points in Adeleke University, Ede, Nigeria. The obtained WPB was shredded and converted to dissolved form using pyrolysis machine @ 4500C. 500g of 60/70 penetration grade bitumen was heated in an oven with 3% (15g) sasobit until it becomes fluidal. The bitumen was modified with 0 - 17% by weight of the bitumen at 2% interval. Mixing was continued for 1hour to produce homogenous bituminous mixtures. Rheological tests were then conducted on the prepared samples using the Brookfield programmable rheometer. The results indicated that addition of DPB improves the rheological properties of absolute viscosity, phase angle, complex shear modulus, rutting and fatigue resistance of modified binder at both 135°C and 165°C. Therefore, DPB can be used to improve bitumen rheological properties and subsequently resist rutting and fatigue on traffic roads. This can best be achieved upon 7% and 5% modification levels at 135°C and 165°C respectively

Measurement and Comparison of Total Electron Content for Assessment of Ionospheric Models during April 7, 2000 Geomagnetic Storms

Ionospheric modelling is a major approach to predicting the behavior of the ionosphere particularly in regions where Global Positioning Systems (GPS) are not readily available. Hence, the objective of this paper is to measure and compare Total Electron Content (TEC) for Assessment of Ionospheric Models during April 7, 2000 Geomagnetic Storms. Measured Total Electron Content (TEC) from experimental records (April 5 - 9, 2000) were compared with those predicted by the improved versions of the International Reference Ionosphere (IRI-2012 and IRI-Plas2015) and the NeQuick models. The mean values of TEC in five days of the months were plotted against the hours of the same day and the root mean square error of the models which shows their deviations from the GPS data were used to observe the diurnal variations in TEC and the performances of the ionospheric models respectively. The data obtained confirmed that TEC has their highest values during the midnight period and lowest values during the sunset period at the Australian stations and we also confirmed that European stations had their highest TEC values during the daytime and their lowest values during the night time. We affirmed that the North American station in USA had its highest TEC values during the night time and lowest values during day time. The Asian station had its highest TEC values during the day time and lowest values during the midnight period. However, NeQuick, IRIPlas2015, and NeQ-IRI produced better estimate of TEC than the IRI-2001 and IRI-2001COR at all locations during the phases of the geomagnetic storm