Marine ecological engineering construction method, asphalt cement-based coating, and preparation method thereof

A construction method for marine ecological engineering by discarded concrete blocks, comprising:

• (1) surveying a sea area of a breakwater construction position:
• surveying dominant species of oysters in the sea area and whether the oysters are attached, surveying air temperature, seawater temperature, dissolved oxygen, plankton, total dissolved inorganic nitrogen, active phosphate, active silicate, Ca2+, Zn2+, K+ and the like for the sea area at different seasons, and surveying typhoon times, strength and the like over the years;
• (2) preparing a lightweight concrete settlement substrate with a rough surface for oyster, wherein the shape of the lightweight concrete settlement substrate for oyster is one of the shapes of a slab-shaped settlement substrate, a wave-shaped settlement substrate and a cylindrical settlement substrate;
• (3) quantitatively collecting and cultivating oyster larvae:
• placing the settlement substrate in a larva collection area of local sea area, where the swimming larvae are mainly in metamorphosis period, stopping collecting the larvae once the amount of the settled oyster larvae is 15-25 larvae/100 cm2, and then moving the settlement substrate to a sea area with rich baits for floating cultivation;
• (4) treating surfaces of discarded concrete blocks:
• evaluating the alkalinity, the internal ion concentration and the permeability of the discarded concrete;
• if the pH is more than 12.5, reducing the alkalinity, and spraying or brushing an emulsified asphalt cement-based coating with high bonding strength and high induction for oyster to settle on the surfaces of the discarded concrete blocks;
• (5) placing discarded concrete blocks:
• in the concentration period of settlement and metamorphosis of oyster planktonic larvae in the local sea area of the next year, adopting a dispersed placement method, placing the discarded concrete blocks with volume of more than 1 m3 individually, and covering each rock with a rope;
• covering multiple discarded concrete blocks with the volume of less than 1 m3 with the ropes to form a discarded concrete block pile with a volume of 1-5 m3, wherein the internal voidage is 40%-60%;
• and connecting the rocks by ropes;
• (6) placing the oyster settlement substrate in site:
• conveying the oyster settlement substrate in which the gonad of oysters develops into mature stage in the step (2) to the sea area for constructing the breakwater, placing one lightweight concrete oyster settlement substrate with the rough surface on single discarded concrete block or discarded concrete block pile and fixing the lightweight concrete settlement substrate for oyster on single discarded concrete block or discarded concrete block pile through a rope;
• in addition, feeding algae or replenishing nutritive salts if necessary according to the planktonic condition of the local sea area;
• and
• (7) monitoring and managing the state of larval settlement:
• monitoring the settlement condition of oyster larvae on the rock surface;
• when the larval settlement density is 30 to 40 larvae/100 cm2, moving away the oyster settlement substrate, monitoring the ecological condition of a breakwater for a long time, and providing corresponding measures according to the practical condition.