Evaluating the Friction Characteristics of Pavement Surface for Major Arterial Road

The performance of the pavement in terms of vehicle safety and tire wear is affected by the friction behavior of the pavement. To highlight the main characteristics that affect the production of better friction resistance of the pavement surface in this work. The micro-texture and macro-texture of the asphalt surface of Baghdad Airport highway were studied using two methods: (sand patch method and the British pendulum test). The sand patch was examined by drawing sand grains of a specific volume, while the micro-texture was analyzed using a BPT under dry and wet surface conditions. All data obtained from the two examinations were analyzed and modelled statistically using SPSS 25 software. Results show that skid resistance of pavement surface increase with the increase of MTD, this increase may be due to the increase of coarse aggregate which lead to increase the roughness of the pavement surface, this increase ranged between (96 - 91%). MTD decreases with the increase of traffic flow due to the friction between the road surface and the vehicle tires leading to increase of smoothness of the road surface. This is mean that MTD is highly affected by the traffic flow and this effectiveness ranged between (84-97%). Skid resistance also is highly affected by the traffic flow with an effectiveness ranged between (81-94%) for both pavement conditions. According to the regression analysis for friction and other parameters, it can be concluded that surface friction values are highly affected by cumulative traffic (asphalt mix deterioration) over time. Doi: 10.28991/cej-2021-03091775 Full Text: PDF

Facies Analysis and Sedimentary Architecture of Hybrid Event Beds in Submarine Lobes: Insights from the Crocker Fan, NW Borneo, Malaysia

Hybrid event beds represent the combined effect of multiple geological processes, which result in complex depositional geometries and distinct facies distribution in marine environments. Previous work on hybrid event beds highlights the classification, origin, and types of hybrid facies. However, in the present study, we discuss the development of hybrid event beds in submarine lobes with an emphasis on the analysis of proximal to distal, frontal to lateral relationships and evolution during lobe progradation. Detailed geological fieldwork was carried out in the classical deep-marine Late Paleogene Crocker Fan to understand the relationship between the character of hybrid bed facies and lobe architecture. The results indicate that hybrid facies of massive or structureless sandstone with mud clasts, clean to muddy sand, and chaotic muddy sand with oversized sand patch alternations (H1–H3) are well developed in proximal to medial lobes, while distal lobes mainly contain parallel to cross-laminated clean to muddy hybrid facies (H3–H5). Furthermore, lateral lobes have less vertical thickness of hybrid beds than frontal lobes. The development of hybrid beds takes place in the lower part of the thickening upward sequence of lobe progradation, while lobe retrogradation contains hybrid facies intervals in the upper part of stratigraphy. Hence, the development of hybrid beds in submarine lobe systems has a significant impact on the characterization of heterogeneities in deep-marine petroleum reservoirs at sub-seismic levels.

Pengaruh Kadar Filler Fly Ash dalam Campuran AC-WC dengan Pasir Pantai Takisung sebagai Agregat Halus Ditinjau dari Aspek Ketidakrataan dan Properties Marshall

Penggunaan fly ash sebagai filler dan pasir pantai sebagai agregat halus dinilai dapat mengurangi kerusakan perkerasan jalan Asphalt Concrete-Wearing Course (AC-WC). Kandungan silika pada fly ash memiliki daya ikat kuat, sehingga dapat memperbaiki Properties Marshall pada campuran. Gradasi pasir pantai yang seragam dapat memperbaiki nilai ketidakrataan. Berdasarkan ulasan di atas penelitian ini bertujuan menganalisis pengaruh kadar filler Fly Ash dengan pasir Pantai Takisung sebagai agregat halus dalam campuran terhadap aspek ketidakrataan dan Properties Marshall, sekaligus menganalisis kadar filler optimum ditinjau dari aspek Properties Marshall. Langkah awal penelitian yaitu pengumpulan data (primer dan sekunder). Berdasarkan data, ditentukan proporsi setiap fraksi dalam campuran sesuai dengan variasi kadar filler. Selanjutnya pencarian KAO dengan agregat halus menggunakan Pasir Pantai Takisung dan dilanjutkan dengan membuat campuran dengan variasi kadar filler fly ash 0%, 3%, 4%, dan 5%. Sebelum sample direndam dan diuji Marshall maupun Volumetrik, sample diuji nilai ketidakrataan dengan menggunakan metode Sand Patch dan pendekatan berat. Hasil penelitian menunjukkan penggunaan pasir pantai sebagai agregat halus dengan filler fly ash dapat memperbaiki nilai ketidakrataan pada permukaan. Penambahan filler fly ash dapat memperbaiki nilai Properties Marshall campuran pasir pantai terutama aspek stabilitas dan MQ. Nilai ketidakrataan yang didapat sebagai berikut; sample pasir sungai = 3,82 m/km, sample pasir pantai = 3,49 m/km, sample kadar filler 3% = 2,63 m/km, kadar filler 4% = 2,54 m/km, kadar filler 5% = 2,59 m/km. Kadar filler optimum yang didapat yaitu 3,3%. Pada kadar filler tersebut didapat nilai Properties Marshall; Stabilitas = 1197,62 kg, flow = 2,32 mm, VFWA = 66,74 %, VMA = 15,01 %, VIM = 4,99 %, dan MQ = 517,02 kg/mm, yang kesemuanya masuk spesifikasi yang telah ditentukan.

A Novel Camera-Based Measurement System for Roughness Determination of Concrete Surfaces

Determining the roughness of technical surfaces is an important task in many engineering disciplines. In civil engineering, for instance, the repair and reinforcement of building component parts (such as concrete structures) requires a certain surface roughness in order to ensure the bond between a coating material and base concrete. The sand patch method is so far the state-of-the-art for the roughness measurement of concrete structures. Although the method is easy to perform, it suffers from considerable drawbacks. Consequently, more sophisticated measurement systems are required. In a research project, we developed a novel camera-based alternative, which comes with several advantages. The measurement system consists of a mechanical cross slide that guides an industrial camera over a surface to be measured. Images taken by the camera are used for 3D reconstruction. Finally, the reconstructed point clouds are used to estimate roughness. In this article, we present our measurement system (including the hardware and the self-developed software for 3D reconstruction). We further provide experiments to camera calibration and evaluation of our system on concrete specimens. The resulting roughness estimates for the concrete specimens show a strong linear correlation to reference values obtained by the sand patch method.

How concrete removal techniques affect the bonding between concrete and repair mortar

Many bonding failures between the substrate and repair mortar are attributed to too aggressive removal of the contaminated concrete and incorrect use of repair materials. To this end, in this study the effect of concrete removal techniques on substrates of different compositions and, as a result, on the bonding with repair mortar has been investigated. Substrate surfaces of different concrete compositions, micro-concrete (MC) and crushed stone concrete (CC), were treated by using three commonly used techniques: grit blasting (GB), jack-hammering (JH), and hydrodemolition/water-jetting (WJ). Automated Laser Measurements (ALM), sand patch tests and surface tensile strength measurements were applied to characterize the substrate surface. According to the results, the co-lateral effects of removal techniques such as WJ are dependent on the concrete mix composition. Moreover, WJ- and JH- treated samples achieved a lower surface tensile strength and bond strength compared to GB-treated slabs.

Performance Evaluation of Slurry Seals Containing Reclaimed Asphalt Pavement

Preventive pavement maintenance methods such as slurry seals are cost-effective treatments that increase the longevity of pavements. The incorporation of recycled materials such as reclaimed asphalt pavement (RAP) into asphalt pavement helps to further reduce costs and energy consumption. The present research studied the feasibility of incorporating RAP into slurry seal mixtures or RAP slurry seals. Two slurry seal mixtures containing cement and hydrated lime as fillers were tested. The first mixture comprised slurry seal made with virgin aggregate and the second used RAP as the aggregate. The wet track abrasion test (WTAT) and loaded wheel test (LWT) were conducted to evaluate the performance of the mixtures. Wet cohesion and friction tests (sand patch and British pendulum) were performed on the selected slurry seal mixtures with the best performance under WTAT and LWT. The results show that it is possible to prepare slurry seal containing RAP. Although the curing time relative to the virgin aggregates increased by 1 h for RAP aggregate, the wear value in the WTAT decreased by half. Lateral displacement and the British pendulum test results improved considerably for slurry seals made with RAP aggregates. The results of the sand patch test on WTAT samples showed that slurry seals made with RAP should be lightly rolled after lay-down to improve their friction life. Cost analysis indicates that the use of RAP as an aggregate in slurry seal decreased costs by up to 14%. RAP slurry seal showed better overall performance with lower cost than the virgin slurry seal.

Determination of Surface Roughness Parameters by Optical Profilometry and Sand Patch Test

In cases when two concrete parts are cast against in different times are not connected by dowels, main contributors to the resistance are cohesion and friction. Shear resistance of the interface is highly dependent on surface treatment and its roughness. In this paper, besides the review of available methods of surface roughness determination, the optical profilometry will be introduced and described. Optical profilometry represents non-contact and non-destructive method for characterizing surface topography. Furthermore, results obtained by abovementioned method will be compared with Sand Patch Test, in order to determine its usability and limitations.

Korelasi Skid Resistance dengan Kedalaman Tekstur pada Permukaan Perkerasan Lentur

Skid Resistance is the force generated between the pavement surface and vehicle’s tires to resist the vehicle advance motion when braking. In this research the correlation between skid resistance value and texture depth on the pavement surface will be determined. The skid resistance value determined by using the British Pendulum Tester (BPT) and to determine the texture depth used Sand Patch Method. The research is conducted directly on a macro textured surface with two methods. The first method is applied on Ngumban Surbakti Road where the samples tested with the same distance from the edge of the pavement along the road; The second method is applied on Jend. Sudirman Road where the samples tested with specific distances from the edge of the pavement until the median. From the results of the analysis, there are some conclusions: (1) there is a positive correlation between the texture depth and skid resistance with a coefficient of determination (R2) = 0.028 on Ngumban Surbakti Road and (R2) = 0.191 on Jend. Sudirman Road;(2) the increase of skid resistance value is directly proportional to the increase of surface texture depth value; and (3) the different methods did not cause significant yield differences.