Viscoelastic Properties, Rutting Resistance, and Fatigue Resistance of Waste Wood-Based Biochar-Modified Asphalt

The purpose of this study is to explore the viscoelastic properties, rutting resistance, and fatigue resistance of waste wood-based biochar-modified asphalt. The biochar with 2%, 4%, and 8% mixing amounts and two kinds of particle size, 75–150 μm and <75 μm, were used as modifiers of petroleum asphalt. Meanwhile, in the control group, a graphite modifier with a particle size of 0–75 μm and mixing amount of 4% was used for comparison. Aged asphalts were obtained in the laboratory by the Rolling Thin Film Oven (RTFO) test and the Pressure Aging Vessel (PAV) test. The viscoelastic properties, rutting resistance, and fatigue resistance of biochar-modified asphalt were evaluated by phase angle, critical high temperature, and fatigue cracking index by the Dynamic Shear Rheometer (DSR) test. In addition, the micromorphology of biochar and graphite was compared and observed by using the scanning electron microscope (SEM). The results show that increasing the mixing amount of biochar gave a higher elastic property and significantly better rutting resistance of the modified asphalt at high temperature. Compared with graphite, the biochar has a rougher surface and more pores, which provides its higher specific surface area. Therefore, it is easier to bond with asphalt to form a skeleton network structure, then forming a more stable biochar–asphalt base structure. In this way, compared to graphite-modified asphalt, biochar-modified asphalt showed better resistance to rutting at high temperature, especially for the asphalt modified with biochar of small particle size. The critical high temperature T(G*/sinδ) of 4% Gd, 4% WD, and 4% Wd was 0.31 °C, 1.57 °C, and 2.92 °C higher than that of petroleum bitumen. In addition, the biochar asphalt modified with biochar of small particle size had significantly better fatigue cracking resistance than the asphalt modified with biochar of large particle size. The fatigue cracking indexes for 2% Wd, 4% Wd, and 8% Wd were 29.20%, 7.21%, and 37.19% lower by average than those for 2% WD, 4% WD, and 8% WD at 13–37 °C. Therefore, the waste wood biochar could be used as the modifier for petroleum asphalt. After the overall consideration, the biochar-modified asphalt with 2%–4% mixing amount and particle size less than 75 μm was recommended.

Evaluation of Susceptibility of Asphalt Binders to Rutting through MSCR Test

Using modified asphalt binder is one of the most effective methods to solve the rutting problem of asphalt pavement, but the traditional G ∗ / sin δ parameter is not enough to characterize the rutting resistance of modified asphalt in field use. In order to accurately evaluate the high temperature performance of asphalt and establish the relationship between the rutting resistance of binder and mixture, two kinds of matrix asphalt and three kinds of modified asphalt were selected for DSR and MSCR tests. G ∗ / sin δ , nonrecoverable creep compliance Jnr, recovery rate R, and other parameters were used to characterize the permanent deformation resistance of the binder, and the correlation between these parameters and the results of rutting test was analyzed. The results show that Jnr3.2 can accurately characterize the permanent deformation resistance of asphalt, while the stress sensitivity index Jnrdiff is not applicable to all types of modified asphalt. In contrast, Jnrslope can better reflect the stress sensitivity of asphalt, and Jnrslope is significantly correlated with the results of rutting test.

Mathematical modeling of improving the characteristics of bitumen for asphalt concrete by modifying

A significant increase in traffic intensity and increased axle loads of vehicles on the roads led to the fact that asphalt concrete is not able to provide the required durability of road surfaces. The durability of asphalt concrete pavements is directly related to the quality of the materials used, primarily bitumen. Bitumen is most susceptible to changes under the influence of traffic loads and weather conditions. At the same time, bitumen largely determines the condition of the road surface. The behavior of bitumen can be changed by modifying it with additives. The novelty of bitumen modification lies in the fact that the addition of polymer to bitumen makes it possible to obtain a road surface that is resistant to cracking at low temperatures and to provide fatigue strength at high temperatures. Rutting resistance is also achieved. An important role in the choice of the modifier is played by economic issues related to the rise in the cost of coating, as well as the need to use additional equipment, the stability of the modified binder during storage and transportation, etc. Carbon nanotubes (CNTs) were used as a modifier for asphalt concrete mixtures. During the experiment, a significant improvement in the main indicators of asphalt concrete mixtures was revealed, as well as the maximum permissible deviations for the amount of binder in the asphalt concrete mixture and for the main indicators were observed. Moreover, the most important thing that has been achieved is a significant increase in rutting resistance by rolling a loaded wheel.

Experimental Evaluation of Moisture Damage and Rutting Resistance for SBS Modified Warm Mix Asphalt Incorporating Recycled Asphalt Concrete

The efforts embedded in this paper have been devoted to designing, preparing, and testing warm mix asphalt (WMA) mixtures and comparing their behavior against traditional hot mix asphalt mixtures. For WMA preparation, the Sasobit wax additive has been added to a 40/50 asphalt binder with a concentration of 3%. An experimental evaluation has been performed by conducting the Marshall together with volumetric properties, indirect tensile strength, and wheel tracking tests to acquire the tensile strength ratio (TSR), retained stability index (RSI), and rut depth. It was found that the gained benefit of reduction in mixing and compaction temperatures was reversely associated with a noticeable decline in Marshall properties and moisture susceptibility indices designated by TSR, and RSI, and even the rut resistance was adversely affected. Modification of WMA mixtures by 3% of Styrene-Butadiene-Styrene (SBS) polymer coupled with replacement of virgin ingredient by 50% of recycled asphalt concrete granted a 20% and 15% growth in Marshall stability and tensile strength, respectively. Moreover, both TSR and IRS indices have risen to 87% and 90%, respectively associated with a 39% increase in rutting resistance ability.

Improving Rutting Resistance of Flexible Pavement Structure By Using Waste Plastic

On these days traffic is increasing faster rate on roads then various type of defects are produced on road that is rutting, raveling etc A pavement structure have different layers purpose to transfered traffic loads to the sub grade. Rutting is one of the pavement distresses that effects the performance of road pavements. Waste plastic is the type of materials to use for improving the performance of flexible pavements against rutting. In this study utilization of waste plastic water bottles, cold drink bottles, polythene bags, parcel package polythene and films. This waste material clean and shredded small particles (1-3cm) sizes. Aggregate heated 170-200° and mix particles with different percentage (3%, 5%, 7%) properly coated on hot aggregate. This plastic waste coated aggregate is also mixed with hot bitumen. And perform some laboratory test (impact value test, moisture absorption test, marshal value test) on the sample and check the property of rutting resistance.

Use of local crumb rubber as modifier, to improve the rutting resistance of bitumen

Bitumen is a critical component in asphaltic pavements and is often the cause of many road failures. The commercial modifiers that are being used to enhance the properties of bitumen are quite expensive; therefore, this article is dedicated to explore the potential of local crumb rubber as bitumen modifier. Two grades of bitumen pen grade (60/70 and 80/100) were modified with local crumb rubber. Rheological properties of modified and unmodified bitumen were evaluated using Dynamic Shear Rheometer. The results indicated an increase in the rutting resistance of bitumen. This indicates that Local crumb rubber can be used to enhance the properties of bitumen.