Investigation of Mixing and Compaction Temperatures of Modified Hot Asphalt and Warm Mix Asphalt

The determination of mixing and compaction temperatures through the Equiviscous method has been defined as the standard method and it is designed for the base bitumen (unmodified bitumen) based on the viscosity measurements. The implementation of the Equiviscous method for the modified bitumen resulted in high mixing and compaction temperatures which may not be required during the construction of the asphalt mixtures. This study aims to investigate several alternative methods proposed in the literature named as high shear rate method, zero shear viscosity method, steady shear flow method, and phase angle method. Besides, the obtained mixing and compaction temperatures results are compared with the standard (equiviscous) method. For this purpose, 50/70 penetration grade bitumen modified with 5 % elastomeric type – Styrene Butadiene Styrene (SBS), and 1.5 % Reactive Elastomeric Terpolymer type – Elvaloy (RET) has been used. The study also aims to measure the applicability of the proposed alternative methods for the warm mix asphalt involving organic and chemical additives. The results have shown that for the polymer modified bitumen, the application of all proposed methods in the literature resulted in lower mixing and compaction temperatures compared to the Equiviscous method. While for the warm mix asphalt, the implementation of the steady shear flow method resulted in lesser temperatures compared to the Equiviscous method

Effects of Warm Mix Asphalt Additives on Aging Characteristics of Bituminous Mixtures

In recent decades, the utilization of the warm mix technologies in pavement constructions is increasing rapidly with rise in public environmental awareness. The durability of a pavement highly depend on the behavior of the pavement against aging induced failures. Therefore this study encompasses the evaluation of short- and long-term aging characteristics of four kinds of Warm Mix Asphalt (WMA) additives. Additives distinctly assessed in this study, consist of two non-foaming (organic and chemical) and two foaming(synthetic and natural zeolite) additives. In order to appraise the proportion of hardening of mixtures containing dierent kinds of additives, indirect tensile strength (ITS) values of both short- and long-term aged specimens were determined. Based on relative aging indices derived from the ratio of ITS values of aged and unaged specimens, comparisons were made between the additives assessing the impact of their utilization on aging characteristics of WMA

Comparison of pavement surface texture determination by sand patch test and 3D laser scanning

A modern highway must be capable of proving traffic safety, comfort to passengers as well as efficient and economical transportation. In view of the increase in the number of traffic accidents due to the developments in automotive industry, the traffic safety has gathered too much consideration in recent years. Skid resistance, on which road safety depends, is closely related to the pavement surface texture. The deterioration due to the traffic loads, especially polishing effect, involves a change in surface texture. In recent years, efforts are needed to develop more advanced technologies for evaluating pavement surface texture. In this study, the 3D laser scanner was utilized to quantify the mean profile depth (MPD) of a pavement at a static location. The surface texture of asphalt concrete pavements was scanned at 31 different locations and the results have been compared with the results of sand patch test. It was found that there is a good correlation between MPD as measured by 3D laser scanning and the m ean texture depth (MTD) as measured by volumetric method (sand patch test)

Post-COVID-19 pain syndrome: A descriptive study in Turkish population

Background: The new type of corona virus has a wide range of symptoms. Some people who have COVID-19 can experience long-term effects from their infection, known as post-COVID conditions. The authors aimed to investigate prolonged musculoskeletal pain as a symptom of the post-COVID-19 condition. Methods: This is a descriptive study on the patients who were diagnosed with COVID-19 in a university hospital, between March 2020 and March 2021. Patient records and an extensive questionnaire were used to obtain relevant demographic and clinical characteristics, including hospitalization history, comorbidities, smoking history, duration of the pain, the area of pain, and the presence of accompanying neuropathic symptoms. Results: Of the diagnosed patients, 501 agreed to participate in the study. Among the participants, 318 had musculoskeletal pain during COVID-19 infection, and 69 of them reported prolonged pain symptoms as part of their a post-COVID condition which could not be attributed to any other cause. The mean duration of pain was 4.38 +/- 1.73 months, and the mean pain level was 7.2 +/- 4.3. Neuropathic pain symptoms such as burning sensation (n = 16, 23.2%), numbness (n = 15, 21.7%), tingling (n = 10, 14.5%), stinging (n = 4, 5.8%), freezing (n = 1, 1.4%) were accompanied in patients with prolonged musculoskeletal pain. Conclusions: Patients with COVID-19 may develop prolonged musculoskeletal pain. In some patients, neuropathic pain accompanies it. Awareness of prolonged post-COVID-19 pain is crucial for its early detection and management

Assessment of Asphalt Binders and Hot Mix Asphalt Modified with Nanomaterials

In the recent times, asphalt binder modification has emerged an inevitable alternative in the paving industry to ensure better performing pavements against the distresses caused by common factors such as; moisture susceptibility and high-temperature sensitivity of asphalt binders. Nanomaterials, as asphalt-modifiers, have proved to be the most promising materials in the industry owing to their higher active surface area and small particle size. This study was devoted to assessing the modification influence of three different types of nanomaterials, including nano-Bentonite, nano-CaCO3, and ZycoTherm, on the properties of asphalt binder and HMA. Conventional and rheological tests on asphalt binders, as well as, Marshall mix design and modified Lottman test on laboratory-prepared HMA specimens were conducted in order to signify the influence of nanomodification. The research findings suggested that nanomaterials can potentially enhance the high-temperature susceptibility resistance, storage stability, and rheological properties of asphalt binder samples. Mix design results revealed that the optimum binder contents decreased and Marshall stabilities were slightly improved with nanomodification. Moreover, the modified Lottman test results indicated that 0.1 % of ZycoTherm increased the TSR by 22 % as compared to the control mixture that infers its efficiency in terms of improving the HMA resistance against the moisture-induced damages

Salter-Harris Type III and Type IV Combined Fracture of the Distal Femoral Epiphysis: A Case Report

Distal femoral physeal fractures are not common but have a high rate of complications. They generally follow one of the patterns described in the Salter-Harris classification. We present a case of combination of Salter-Harris type III and type IV injury. Our case was a 15-year-old boy who had a motor vehicle accident. There was swelling, ecchymosis, severe pain, and valgus deformity, because of medial proximal fracture fragment, on the left knee. We deemed that Salter-Harris type III and type IV combination fracture in our case has not been previously reported. We prepared this paper in consideration of its contribution to the literature

Ground Deformations Observed After 23.10.2011 M\u3csub\u3ew\u3c/sub\u3e 7.2 VAN Earthquake (Turkey)

A destructive earthquake with a moment magnitude of 7.2 occurred in the north of the Van province (Turkey) on 23rd October 2011 at 13:41 local time and caused approximately 600 deaths and more than 4000 injuries. Many damaging aftershocks were recorded for more than a month after the main shock including a triggered earthquake (Mw 5.6) located in the southern district of Van, namely Edremit, on November 9th, 2011 which caused additional damage and casualties. After the Mw 7.2 Van earthquake, earthquake-induced ground deformations such as liquefaction and lateral spreading were extensively observed around the shores of Lake Van and in the floodplains of rivers. The Karasu River floodplain, which is one of the major streams in the region, severely suffered from liquefaction and lateral spreading. In this study, a brief overview of the Mw 7.2 Van earthquake as well as earthquake-induced ground deformations is presented. Then, the results of field reconnaissance on liquefaction and lateral spreading features observed in the Karasu River floodplain are explained. Furthermore, subsurface characteristics of liquefied layers are documented considering the data obtained from a borehole drilled just on top of the sand boil after the earthquake. The borehole data indicate that the liquefaction occurred in a sandy zone with very shallow groundwater level in the Karasu River floodplain

Adjustment disorder after botulinum toxin injection in an adolescent palatal myoclonus case: The importance of informed consent in the treatment of neuropsychiatric disorders in children and adolescents

No Abstrac

Investigation of Different Laboratory Aging Methods of Bituminous Mixtures

The predicted performance and service life of the pavement depend largely on the properties of bitumen used in the mixtures. The most important feature of bitumen, which has profound effect on the performance of the road is durability. The durability of bitumen is expressed as the resistance to aging. In this study, the bituminous mixture aging was performed instead of bitumen aging in order to represent the aging in the field in the best possible way. The aim of this paper is to evaluate different proposed laboratory aging methods (NCHRP 09-52, NCHRP 09-54 and RILEM) in relation with the current Standard AASHTO R30 (Standard Practice For Mixture Conditioning of Hot Mix Asphalt standard) and to make comparison with the samples performance taken from the field in terms of Indirect Tensile Strength (ITS). The level of aging has also been compared with the samples taken from recently constructed pavement surface and from the five years old pavement surface. Results depicted that, laboratory aging methods revealed the field aging properties on the unaged bitumen. Based on the results, 2 hours forced draft oven aging at 135°C is recommended as short term aging condition because, 2 hours or 4 hours short term forced draft oven aging did not yield significant variation in terms of ITS values. Additionally, 120 hours (5 days) oven aging of compacted samples at 85°C can be recommended as long term aging condition

Effects of pavement surface deformations on traffic flow

Pavement surface deformations have a significant effect on speed profile of vehicles and traffic flow conditions. These deformations limit driving properties and increase vehicle operation and maintenance costs. Additionally, they cause many problems such as accidents, slower movement speeds, capacity loss and severe discomfort states. There are many factors having an effect on road capacities and they vary according to different road and traffic flow conditions. In this study, it is aimed to investigate and develop models to estimate shockwave and bottleneck forming, capacity loss and speed reduction, which occurred on examined road links caused by pavement deformations. For the prediction of road capacity, flow–density (q–k) relationship, bottleneck and shockwave analysis methods were used. In the scope this study, deformed road links were divided into three sections; Section A – before deformation zone, Section B – deformation zone, and Section C – after deformation zone. All three sections were investigated and empirical results were obtained. According to analysis results, it was found that pavement surface deformations have a negative effect on the level of road service capability. Obtained results also showed that there are significant reductions in capacity relatively by up to 44 and 26% would result from surface deformations on deformed lanes and non-deformed adjacent lanes