人妻 制服 出轨 中字在线

helpline:+8618653298567

Service time

24 Hours Service

Write to us

sg@sgstone.net

E-mailsg@sgstone.net

Contact Us+8618653298567

Drainage function of curb stone

May 01, 2019

The upper layer of curbstone is made of ordinary concrete, and its impermeability can prevent the pavement rainwater from being poured into the pavement structure, and at the same time, the surface layer has a strong structural strength; the lower layer is made of porous concrete to form a water-permeable layer, which allows water in the pavement structure to pass through The permeable layer is smoothly discharged (usually the same cross section of the road, the road is higher than both sides, and the water inside the pavement structure flows to both sides under the action of gravity, and the porous concrete layer that enters the edge stone is discharged when it reaches the edge of the road).


Related News

Recommended

人妻 制服 出轨 中字在线