Papers by Author: Shao Peng Wu

Abstract: Servicing in the natural environment, asphalt pavement is often exposed to the various aqueous solution, however, the effect of different media aqueous solution on road performance of asphalt mixtures remains ambiguous. In this study, the influences of water, acid, alkali and salt solution on volume of air voids (VV), tensile strength rate (TSR), low temperature performance of 70^# asphalt mixtures and SBS modified asphalt mixtures were investigated through freeze-thaw cycles test, void ratio test, Lottman test and Three-point Bending Fracture (TBF) test. The results indicated that freeze–thaw cycles influenced the road performance of asphalt mixtures significantly, increased the air void of asphalt mixtures, and reduced tensile strength ratio and failure strain of asphalt mixtures. Compared with the distilled water, the damage of acid, alkali and salt solution on the road performances of asphalt mixtures were more serious, especially alkali solution to tensile strength rate and failure strains in low temperature, and salt solution to VV. The moisture corrosion resistance of SBS modified asphalt mixtures is better than that of 70^# asphalt mixtures.

Abstract: In this study, three typical tires from bicycles, passenger-cars and trucks were collected and ground into crumb rubber modifiers (CRM) with different particle sizes to modify the asphalt binder. The composition and surface morphology of the three CRMs were analyzed by thermogravimetric analysis (TG-MS) and scanning electron microscopy (SEM). The rheological properties of the binder were evaluated using a dynamic shear rheometer (DSR) and a bending rheometer (BBR). The results show that the main rubber compositions in the bicycle tire (B), the passenger tire (P) and the truck tire (T) are butyl rubber (IIR), styrene-butadiene rubber (SBR) and natural rubber (NR), respectively. Adding CRMs improve rheological properties of base binder. Due to the differences between the composition and the structure, the rheological properties of the P CRM and T CRM containing more SBR and more NR are better at high temperatures and lower temperatures, respectively. And finally the CRM resources and particle size determine the rheological properties of modification effect of base binder. The results can be used to guide the classification and disposal of waste tires. According to the expected modification effect of the asphalt binder, the productions of asphalt pavement construction are enhanced by the high quality products of CRMs.

Abstract: Currently, many inorganic materials are investigated for modifying asphalts, but biomass ash is rarely applied to the modification of asphalt. In this present work, rice-husk-ash, as a representative of the biomass ashes, was added as a modifier to evaluate the related performance. The result showed that the basic performance, aging resistance, and high-temperature performance of modified asphalt has been improved, which proves that biomass ash can be used as an asphalt modifier for resource reuse.

Abstract: Steel slag, a kind of industrial waste, has been considered applying in road construction as aggregate based on abundant indoor tests. The permanent deformation performance of asphalt mixture with Basic Oxygen Furnace (BOF) slag is evaluated by test with UTM-25 and simulation with equations at different temperatures and various stress levels in this study. Results show that the permanent deformation behavior of BOF base asphalt mixture is relatively sensitive to temperature and it can be perfectly modeled with proper equations, otherwise, strain per load cycle of specimen is responsible for mixture failure instead of accumulated permanent strain.

Abstract: With the self-diagnosis function of the self-monitoring asphalt concrete, we can evaluate the health status of pavement according to feedback on the electrical signals when it is under variation load. In this paper, indirect tensile test and flexural modulus test were used to study the low-temperature properties of self-monitoring asphalt concrete. The test results show that the performance of self-monitoring asphalt concrete has a strong sense of temperature. The result of low-temperature properties provides a reference for the further study of self-monitoring asphalt concrete.

Abstract: Self-monitoring asphalt concrete has a good strain and damage self-sensing behavior. We can evaluate the structural health and service life of asphalt concrete by the monitoring of damage. In this paper, some construction technology research, including electrode arrangement, temperature control, mixing technology, transportation requirements, compaction technology, has done through the paving of self-monitoring asphalt concrete test section. The results of research provide a reference and guidance for construction of self-monitoring asphalt concrete in future.

Abstract: There is an important effect on road safety with no lighting facilities near the wild road. With the piezoelectric materials embedded in the asphalt concrete as the smart aggregates, the piezoelectric asphalt concrete transforms the vibrational energy of road surface into electrical energy, to supply the road lighting facilities or be stored up. In this study, the electrical energy of piezoelectric-embedded asphalt mixture by using UTM and wheel tester. The results show that PMnS-PZN-PZT ceramic doped with 0.45wt% Fe2O3 (4mm×8pieces) be embedded in the AC-10 asphalt concrete which can obtain well road performance and micropower electrical energy.

Abstract: The effect of substitution of recycled aggregate by natural aggregate on related properties of blended aggregate (without asphalt and mineral filler) and asphalt mixture was investigated in this paper. Demolition waste obtained from Wenchuan earthquake-damaged buildings was used as recycled aggregate in AC-25 asphalt mixture. The absorption, specific gravity and strength of both blended aggregate and asphalt mixture were tested. Results indicate that fine recycled aggregate is not suitable to be used in asphalt mixture because of its high absorption. The substitution of recycled aggregate by natural limestone aggregate can decrease the asphalt absorption and increase the effective specific gravity and indirect tensile strength of asphalt mixture. The quantitative relationship between related properties of blended aggregate and asphalt mixture was obtained. It was concluded that the substitution of recycled aggregate by natural aggregate is a feasible way to use recycled aggregate in asphalt mixture.

Abstract: Abstract: The anti-aging asphalt modified by Supramolecular Ultra Violate(UV) Light Resistant material which is Layer double hydroxides (LDHs)was prepared in this paper, by using mechanical mixing, LDHs by various mass ratio were added into different typical asphalts. Taking the influence of the factors into account, including mechanical dispersing technologies, reaction conditions(temperature and time), content of the LDHs, the mutual consistent of LDHs among asphalt and storage stability was studied by segregation process and microstructure analysis (X-ray diffraction、Scanning Electron Microscope). Then after thin-film-oven-test (TFOT) and the artificial accelerated UV aging tests to simulate long-term UV aging, basic properties tests were conducted in this paper. The results showed that the UV anti-aging properties of the asphalt were greatly improved. Key words: LDHs; preparation manners; UV anti-aging

Abstract: Two classification methods for fine recycled aggregate used in asphalt concrete were investigated in this paper, respectively classifying by fine recycled aggregate properties and asphalt concrete properties. When classifying by fine recycled aggregate properties, all test results of fine recycled aggregate properties can meet the technical requirements of China with obvious differences in quality. When classifying by asphalt concrete properties, fine recycled and natural aggregate was respectively used to prepare asphalt concrete with the same gradation, the same asphalt, the same limestone mineral filler and the same coarse natural aggregate. Some related properties of asphalt concrete were discussed to classify fine recycled aggregate. It is proposed in this paper that fine recycled aggregate should be classified into three types by asphalt concrete properties and the proposed classification criterion is given.