Effects of Concrete Block Pavement on Flow Retardation Factor

Abstract

KEY WORDS: sustainable urban drainage system, low impact development, surface runoff, hydrological model, paving blocks ABSTRACT:Surface roughness has an important role in retarding the runoff velocity. The increase in paving blocks usage, particularly in urban areas, can change the surface roughness of the land. This study investigated the effects of four types of concrete block pavements (CBPs) in retarding the surface runoff velocity. Three design parameters based on CBP properties that considerably influenced the flow retardation were promoted. They were opening ratio (Or), void ratio (Vr) and straight channel ratio (Sr). A tilted plot equipped with a rainfall simulator was used to investigate the influence of surface slope and rainfall intensity to the flow on various CBPs. A modified dye tracing method in view was performed to monitor the surface flow velocity under various rainfall intensities. Flow retardation coefficient (Frd) were calculated based on velocity data on smooth pavement and on CBPs layer measured under the same slope and rainfall intensity. The results showed that flow retardation coefficient increased with an increase in openings ratio, rainfall intensity and surface slope. The relationship between flow retardation coefficient and all design parameters was expressed by a linear regression function. A further study is required to increase the accuracy of the model by modifying the regression function and increasing the variation of design parameters.

Hydraulic Performance of Concrete Block Pavement under High Rainfall Intensities

“…Pav2 had the smallest effect of surface slope due to the flow path formed by the paving block arrangement causing the water penetration was more affected by the rainfall intensity than the surface slope. These results supported the results of Collins [1] and Sedyowati [15]. While on pav1 and pav3 the arrangement pattern did not cause the occurrence of a straight flow path that led to water penetration.…”

“…Figure 5 describes that the increase in rainfall intensity led to the increase in roughness number. According to [5] and [15], the greater rainfall intensity will lead to a greater raindrop splash. It also can be seen that the roughness number increased with an increase in surface slope.…”

Hydraulic Performance of Permeable Asphalt and Picp in Swmm, Validated by Laboratory Data

“…For this reason, the rainfall intensities applied in the laboratory tests were 35 mm/h and 70 mm/h, corresponding to rains of 15 minutes duration and return periods of 2 and 10 years for the Igeldo meteorological station IDF curves [19], located in the municipality of Donostia/San Sebastián. In that respect, previous laboratory tests for permeable pavements selected rainfall intensities ranging from 5 mm/h to 60 mm/h [5], [9], [10]. For measuring the infiltrated flows and generate the output hydrographs, a hydrograph bucket was placed at the exit of the test bench (6 and 7 in Fig.…”

“…Permeable pavement systems have become an important integral part of sustainable urban drainage systems despite the lack of corresponding high-quality research in comparison to other research areas [4]. Some research carried out to test permeable pavements (PA and PICP) and its performance under laboratory-controlled conditions have been done by Andrés-Valeri et al [5], Huo et al [6], Lucke and Beechman [7], Rodriguez-Hernandez et al [8], Sañudo-Fontaneda et al [9] and Sedyowati and Susanti [10].…”