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Investigation of drying shrinkage effects on sloped concrete-concrete composites
Published in Günther Meschke, Bernhard Pichler, Jan G. Rots, Computational Modelling of Concrete and Concrete Structures, 2022
D. Daneshvar, K. Deix, A. Robisson, Behrouz Shafei
Moreover, during the lifetime of concrete overlays, standing surface water is a major concern. Ponding of water on the overlay surface can result in slippage, hydroplaning, and icing in winter, while facilitating the gravitational ingress of standing water into the reinforced concrete substrate (Smith et al. 2014). A sufficient transverse slope, however, can ensure the proper drainage of surface water from the overlay and minimize its associate issues. To drain off the surface water, a transverse cross slope is typically considered for the overlay. The American Association of State Highway and Transportation Officials (AASHTO) policy on geometric design of highways and streets recommends a cross slope of 2% for usual conditions to mitigate the risk of hydroplaning. Depending on the rainfall and application, a lower or higher cross slope can also be implemented (AASHTO 2011).
Closed Drainage Systems
Published in Saeid Eslamian, Faezeh Eslamian, Flood Handbook, 2022
Water depth is an important factor to determine whether hydroplaning occurs because an empirical formula for the initiation of hydroplaning for a vehicle's speed is a function of the tire tread depth, pavement texture depth, water film depth, and tire pressure (Young et al., 1993). A minimum cross slope of 2% is recommended and has little effect on driver stability and pavement friction (Gallaway et al., 1979).
Pavement Drainage Structures
Published in G.L. Sivakumar Babu, Prithvi S. Kandhal, Nivedya Mandankara Kottayi, Rajib Basu Mallick, Amirthalingam Veeraragavan, Pavement Drainage, 2019
G.L. Sivakumar Babu, Prithvi S. Kandhal, Nivedya Mandankara Kottayi, Rajib Basu Mallick, Amirthalingam Veeraragavan
The minimum grade for a gutter is 0.2% for curbed pavements. For sag vertical curves, a minimum of a 0.3% slope should be maintained within 15 m of the level point in the curve. In a very flat terrain, the slopes can be maintained by a rolling profile of the pavement. For one lane, the minimum pavement cross-slope is 0.015 m/m, with an increase of 0.005 m/m for additional lanes. Slopes of up to 2% can be maintained without causing driver discomfort, whereas it may need to be increased above 2% for areas with intense rainfall.
Estimation of water film depth for rutting pavement using IMU and 3D laser imaging data
Published in International Journal of Pavement Engineering, 2021
The slope of transverse profile depends on the title of survey vehicle related to the pavement surface, while it is irrelevant to cross slope. Because cross slope is important for pavement drainage evaluation, transverse profile should be rotated to coincide with cross slope. Pavement deformation appearing on wheel path affects slope extraction. Therefore, the inner and the outer edge of profile is used to determine the rotation axis. Figure 6(d) shows the rotated transverse profile in horizontal level, and Figure 6(e) shows the calibrated transverse profile combining with cross slope. The calibrated transverse profile is used for pavement rutting measurement, and its coordinates are established as shown in Equation (4). where f: the ith point on transverse profile, xi: the lateral position of the ith point on transverse profile, mm; yi: the height of the ith point on transverse profile, mm.
Placement of ultra-high performance concrete for inclined-surface pavement
Published in Road Materials and Pavement Design, 2021
Tae Yong Shin, Jae Hong Kim, Kyung-Taek Koh, Gum-Sung Ryu, Kejin Wang
Roadways and pavements in civil infrastructures are often designed with various types of slopes in order to meet topographical, environment and safety requirements. Some typical slopes, as illustrated in Figure 1, are (1) running slope – this is in the driving (longitudinal) direction, designed based on a given topographical environment, and typically no more than 17%; (2) cross slope – this is perpendicular to the driving (transverse) direction, serves as an essential component for road surface drainage, and is commonly set at 2.0%; and (3) slope of super-elevation – this is generally 5–8% in the transverse direction, and is designed to prevent slippage of vehicles around curves based on the designed driving speed and the roadway curvature (AASHTO, 2001; Dispenza, 2014).
Hydraulic Performance of Vertically Depressed And Non-Depressed Grate
Published in Urban Water Journal, 2019
Sarah Alia Md Wakif, Nuridah Sabtu
Figure 4 shows the comparison of the hydraulic efficiency between a depressed and a non-depressed gully grate for an intermediate system. Overall, results obtained showed that the efficiency of a non-depressed (normal) gully grate for all bed levels is higher compared to a depressed inlet. However, slope 1:50 behaved differently where the difference between a depressed and non-depressed gully grate is minimal. Both longitudinal and cross slopes influence the behaviour of the surface runoff towards the gully grate as the longitudinal slope represents topographic conditions of the catchment where the runoff will follow gravity and flow in diagonal path. However, flow on a longitudinal slope is preferable compared to zero slope as it helps to facilitate water in the longitudinal channel of the road/highway. Meanwhile, cross slope is a must for all roads to drain the surface runoff from the pavement to the road edge (gully inlets) (DMRB 1999b).