4) OLD STYLE
Older catch basins used brick and morter. Masonry will always succumb to the powerful effects of weather. Masonry materials such as brick, block and concrete are “breathable” materials. Salt water enters the voids and cracks of the masonry such as deteriorated mortar joints or cracked and broken brick. Not only are the masonry materials “breathable”, but the brick, mortar or concrete is now loaded with salt and water. When the water evaporates, the salt is still left behind. Being a hygroscopic material (water absorbant), the residual salt now allows these surfaces to take on more water than before, intensifying the already brutal effects of freeze/thaw cycles.
Once the blocks start braking apart it causes the catch basin to collapse inward. This then causes the sub-base to wash out and fall into the basin essentially taking the asphalt's support with it.
Sometimes these old catch basins need to be completly repaced with new precast concrete catch basins. We then use reinforced modulock rings to support the grate, which are designed to handle the stress of a heavy loads and prevent cracking.