Bitumen plays a significant role in our daily lives, primarily used in road construction. The main source of bitumen is oil refineries, and bitumen from Qayyarah is considered an important resource in Mosul. The oil from Qayyarah is a heavy crude with an aromatic origin, and the high-productivity bitumen can be extracted from it, reaching up to 48% and more than a thousand tons daily. However, it fails the indirect tensile strength tests of the asphalt mixtures used in road paving. We attempted to improve its engineering properties, particularly by increasing the indirect tensile strength, using three treatment methods for Qayyarah bitumen, so it remains competitive in the Iraqi market by utilizing cheap and readily available materials like elemental sulfur, low-density polyethylene waste, and C9 petroleum resin, each mixed in two different ratios for processing to reduce industrial operation costs. Our goal was to help Qayyarah bitumen succeed in the engineering mixtures, with the added ratios being 1% and 2% for elemental sulfur, low-density polyethylene, and petroleum resin C9. The results were excellent, showing a clear improvement in the indirect tensile strength test of the asphalt mixtures, an increase in their load-bearing capacity (Marshall test), and homogeneity in Scanning Electron Microscope (SEM) images. The prepared samples did not suffer from phase separation and were within the allowable range.

The tensile strength (σ t) of a rock plays an important role in the reliable construction of several civil structures such as dam foundations and types of tunnels and excavations. Determination of σ t in the laboratory can be expensive, difficult, and time-consuming for certain projects. Due to the difficulties associated with the experimental procedure, it is usually preferred that the σ t is evaluated in an indirect way. For these reasons, in this work, the adaptive network-based fuzzy inference system (ANFIS) is used to build a prediction model for the indirect prediction of σ t of sandstone rock samples from their physical properties. Two ANFIS models are implemented, i. e. ANFIS-subtractive clustering method (SCM) and ANFIS-fuzzy c-means clustering method (FCM). The ANFIS models are applied to the data available in the open source literature. In these models, the porosity, specific gravity, dry unit weight, and saturated unit weight are utilized as the input parameters, while the measured σ t is the output parameter. The performance of the proposed predictive models is examined according to two performance indices, i. e. mean square error (MSE) and coefficient of determination (R2). The results obtained from this work indicate that ANFIS-SCM is a reliable method to predict σ t with a high degree of accuracy.

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.

The tensile strength of rocks plays a noteworthy role in their failure mechanism, and its determination can be beneficial in optimizing the design of the rock structures. Schistose rocks due to their inherent anisotropy in different foliation directions show a diverse strength at each direction. The purpose of this work was to compare and assess the tensile strength of phyllite, which was obtained in direct and indirect tensile tests in different foliation directions. To this end, several phyllite specimens with different foliation angles (0º , 30º , 45º , 60º , and 90º ) related to the loading axis (β ) were prepared. Finally, the direct tensile test, diametrical and axial point load tests, Brazilian test, and Schmidt hammer test were conducted on 188 samples. The results of the experimental tests revealed that the maximum and minimum tensile strengths in direct tensile testing tension were directly related to the angles of 0º and 90º . Also it was observed that the Brazilian tensile strength overestimated the tensile strength. Furthermore, an exponential correlation was introduced between the direct tensile strength and the Brazilian tensile strength.

In recent years, vast extent and severity of permanent deformations has created some concerns regarding the effects of this type of failure on performance of asphalt pavements. To investigate the rutting of asphalt mixtures, it should be noted that these mixtures are multiphase combination of aggregates, binder and voids. Arrangement of aggregate particles (aggregates skeleton) in the internal structure of hot mix asphalt has an important role in mechanical performance of the mixture, especially on its rutting resistance. In most regulations for asphalt mixtures' design, only macroscopic parameters such as void content and binder volume, along with mechanical characteristics, such as rutting resistance, are used as the main criteria for quality control. But so far, visual analysis and micro-properties of asphalt mixtures (internal structure of the pavement) have not been considered much. In this article, micro-effectiveness properties of asphalt mixtures such as number of contacts, length of contacts and orientation of contacts for rutting performance of 16 types of mixture (two types of gradation, two types of binder, two types of aggregates and two types of filler) were considered. In this research, the results of rutting resistance (flow number) and micro parameters (as number of contact, length of contact and orientation of contact), determined by image processing (by using iPas2 software), and indirect tensile strength were compared. The analysis showed that rutting performance depends to a large extent on micro characteristics of asphalt mixtures and these properties could be used as a control tool in design of asphalt mixtures.

The rapid growth of traffic, especially heavy vehicles passing by repeated loading, poor quality asphalt mix and not reaching different the required density of asphalt pavement can cause asphalt damage. One of the most important types of flexible pavement failures, is permanent deformation, which are known by the name rutting. Rutting is done by aggregation of Permanent deformation and irreversible through the pavement layers under traffic loading repeated. Through the all different layers involved in rutting, permanent deformation in the surface layer of pavement is allocated to the main contribution of rutting, thus Provide an appropriate mix design, attention to the potential risk of permanent deformation asphalt mixtures that weakness indication shear resistance in the asphalt is essential to be considered. On the other hand the specified flow number is beginning marker for Shear deformation in asphalt mixtures is known as a marker for evaluation of asphalt mixtures rutting. In this study, we have tried to build the asphalt samples with Marshall method, that including range of the aggregates, asphalt, aggregate, filer and bitumen percentage with the development of a relationship between obtained flow number from the dynamic creep test, tensile strength from indirect tensile test and the parameters of the Marshall mix design while providency administrative costs, predicted the mixture rutting status, without spending extra time. The accuracy of this model was confirmed by the artificial neural network, makes it possible to prevented produce concrete with low shear resistance in the laboratory and before factory manufacture. Thus, considerable savings in future time and costs there would be in mix design.

There has been a dramatic growth in asphalt recycling and reclaiming as a technically and environmentally preferred way of rehabilitating deteriorated pavements over the last couple of decades. One of the latest asphalt recycling techniques is cold in-place recycling using foamed bitumen. In recent years, there have been a number of successfully implemented cold in-place asphalt recycling projects in Iran; and it seems that the utilization of this method is gaining more acceptances amongst the road authorities and the contractors. At the same time, endeavors to evaluate the performance properties of foamed bitumen mixes were started and are still in progress. The present research, studies the mechanical and the performance properties of foamed bitumen mixes. In the first phase of the project, the effect of aggregate grading, bitumen and cement content and compaction efforts, on resilient modulus and indirect tensile strength (ITS) of 144 foamed bitumen specimens (of various curing conditions) has been investigated and analyzed. In the next phase, the effect of above parameters on resilient modulus and unconfined compressive strength (UCS) of 108 different samples was studied. Results indicate that for the tested materials, changing the aggregate grading from coarse to fine didn’t have a significant effect on resilient modulus, ITS, UCS and the moisture susceptibility of the specimens. Also the effect of increasing bitumen content from two to four percent is negligible. On the contrary, adding one percent cement and increasing it to two percent considerably improved the moisture susceptibility and the mechanical properties of the mixes. Based on the obtained data, a regression model between resilient modulus and ITS of the foamed bitumen mixes was developed to facilitate the prediction of the resilient modulus based on the corresponding ITS values.

Strength measurement of rock requires testing that must be carried out on test specimens with particular sizes in order to fulfill testing standards or suggested methods. Often, the coring process breaks up the weaker core pieces, and they are too small to be used in either index tests or conventional strength tests such as point load index (Is) and Brazilian tensile strength (BTS). One of the index tests to indirectly determine the rock strength is the block punch index (BPI) test, which requires flat disc specimens without special treatment. This study aimed to evaluate the applicability of the BPI test for predicting the uniaxial compressive strength (UCS), BTS and IS of the sandstones by empirical equations. Also, we have compared the performance of the BPI and IS for predicting the UCS and BTS. It was experimentally shown that BPI is a reliable method for predicting the UCS, BTS and Is of the sandstones under study. Moreover, the results indicate that BPI could be utilized with same importance as Is for predicting the UCS, while predicting the BTS by Is appears to be more reliable than BPI.