جستجوی مقالات مرتبط با کلیدواژه "asphalt rutting" در نشریات گروه "عمران"

The present research was conducted with the aim of investigating the effect of the type of filler on the mechanical properties of the stone mastic asphalt (SMA). For this purpose, five types of fillers, including silica filler (SF) as the base filler in the control sample, Portland cement (OPC) and limestone powder (LSP) as common fillers, and recycled glass powder (RGP) and calcium carbide waste (CCR) as recycled fillers, were used in their pure form or combined with each other. In order to investigate the resistance of the samples against rutting, the Marshall test was used to obtain the Marshall strength (MS) and especially the Marshall coefficient (MQ). Also, resistance to cracking and moisture sensitivity were also evaluated by performing the Indirect Tensile Strength (ITS) test in dry and saturated conditions and obtaining the Tensile Strength Ratio (TSR). The results have shown that the samples containing recycled fillers had the best performance in improving the properties of SMA asphalt. such that the use of the combination of recycled fillers, in addition to improving the properties of SMA compared to samples containing silica fillers, The values of MS, MQ, ITS, and TSR have increased by 36, 19, 24, and 31%, respectively, compared to the best results obtained using common fillers. Therefore, the use of RGP and CCR compounds as fillers in SMA asphalt, in addition to helping to protect the environment, natural resources and economic savings, can also be technically very effective in improving the service life of asphalt mixtures.

Rutting is one of the most important deteriorations in flexible pavements and a significant amount of annual maintenance and rehabilitation funds are spent for its repair. Permanent deformations increases, which leads to increasing rut depth, can cause irrepairable problems in asphalt pavements. On the other hand, in Marshall method, which is known as the main method of asphalt mixtures mix design in Iran, the lack of a simple test to determine specimen resistance to permanent deformation is sensible. Although there are many devices to measure the rutting nowadays, but none of them have the ability to be used at site level. In addition, prevalent methods of evaluating rutting potential of asphalt mixtures are usually expensive and time consuming. The abovementioned factors necessitate development of a simple laboratory method that not only enjoys an acceptable precision but also is able to predict specimens rutting performance with low cost within the short time. In this research, one type of aggregate, one type of gradation, two types of bitumen, one type of filler, and three bitumen contents were used to prepare Marshall asphalt mixture specimens. After performing the main tests on specimens, IDT test results and Marshall parameters were used to develop a mathematical model to estimate specimen Wheel Track apparatus rut depth. The presented model measures rutting resistance using a combination of indirect tensile strength test results and Marshall parameters. The model is validated using artificial neural network, which makes it possible to evaluate rutting potential while OBC is being determined in a laboratory. Therefore, not only is there no need for expensive instruments of rutting test, but also a remarkable time saving in mix design procedure is achievable.