Effect of Drying on Clay Clogging of Pervious Concrete

Rao, Yunkang; Zhang, Junyu; Yang, Tao; Feng, Jun

doi:10.1061/(asce)mt.1943-5533.0003790

Cited by 7 publications

(8 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…More than 77% of the total retained clay occurs within the vertical region 24–72 mm below the sample surface, while less than 23% occurs within the remaining region. This result is generally consistent with a previous study 25 . The clay suspension spread on the sample surface flowed into the interior at a high infiltration velocity and seepage force; thus, the near-surface region retained a few particles.…”

Section: Resultssupporting

confidence: 94%

“…1 , an overflow hole was located at a height of 250 mm above the sample surface, implying a 250-mm water head difference. The permeability ( K ) was calculated according to the following equation, which was also used in previous studies 2 , 25 . where a and A denote the area of the sample and graduated cylinder (mm 2 ), respectively; t denotes the time for water to pass from level to in the cylinder (s); and L denotes the length of the sample (mm).…”

Section: Methodsmentioning

confidence: 99%

“…The drying was intended to mimic hot and sunny field conditions, which typically occur and dry the clogged pavement after rain events. In field conditions, the drying temperature of 50 °C, which was also used in published studies 19 , 25 , likely occurs frequently, particularly during summer.…”

Section: Methodsmentioning

confidence: 99%

“…Considering that pressurized water during the washing cycles is able to enter the internal structure of PC, the scouring force of washing water during pressure washing may affect clay retained within any depth of PC. However, the scouring force and cleaning effect of washing water may differ at different depths of PC 25 . Specifically, pressure washing with a high scouring force may easily wash away the particles near the surface.…”

Section: Introductionmentioning

confidence: 99%

“…Accordingly, it is necessary to investigate the dried clay-clogging mechanism, which will improve our understanding of clay clogging in PC. We previously investigated the influence of drying on clay clogging, but did not compare clay clogging with sand clogging or investigate the vertical sediment distributions of sand-clogged PCs 25 .…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Comparison between sand and clay clogging mechanisms of pervious concrete pavement

Rao

Yang

et al. 2022

Sci Rep

Self Cite

View full text Add to dashboard Cite

Pervious concrete (PC) pavement has been widely accepted as a green infrastructure but is prone to clogging. This study comparatively investigated sand and clay clogging mechanisms of PC and vertical sediment distributions of sand-clogged and clay-clogged PCs. Clay and three sizes of sand were used to clog PC under two exposure methods (no drying and drying). X-ray computed tomography (CT) was used to scan the clogged samples before and after 30 pressure washing cycles. The clogged permeability and permeability after each washing cycle were measured. The clogging patterns of sand depend mainly on sand particle sizes relative to PC pore sizes. The applied fine sand, coarse sand, and medium sand cause easy-passing clogging, surface clogging, and full-depth clogging, respectively. After clay clogging, more than 77% of the total retained clay occurs within the vertical region 24–72 mm below the sample surface; the most clogging (the lowest-permeability layer) occurs at a depth of approximately 48 mm. The dried clay retained within the region 40–120 mm below the surface (especially within the lowest-permeability layer) is hard to wash away because the drying process increases the cohesion of internal clay particles and clay adhesion to the rough, tortuous pore wall of PC. The clogged normalized permeability of 0.154 and permeability recovery ratio of 4.91% in dried clay-clogged samples are lowest among all the samples. However, pressure washing readily washes away the retained undried clay. Accordingly, it is recommended that pressure washing is used to eliminate the clogging effect of dried clay before hot, sunny exposure conditions dry the retained clay. This study provides evidence for developing effective pavement maintenance strategies.

show abstract

Section: Resultssupporting

confidence: 94%