(57) Provided are high-strength concrete and a preparation method therefor. The concrete comprises lignin, regenerated micropowder, cement, water, sand, gravel, and a water reducing agent. The regenerated micropowder is regenerated micropowder of waste concrete, and the preparation method comprises: separating solid construction waste, then performing impurity removal and crushing processing, and using a ball mill to grind the solid construction waste into dust having a particle size of less than 0.16 mm. The lignin is waste wood lignin, and the extraction method comprises: crushing wood, using a sodium hydroxide aqueous solution having a mass concentration of 5% to stir and extract at 80 °C for 1-2 hours to obtain a black lignin alkaline solution, adding a hydrochloric acid solution having a mass concentration of 30% into the alkaline solution for stirring to reduce the pH to 7.0, and standing for layering to obtain the lignin. The strength grade of the concrete is remarkably improved, and the recycling of the construction waste is also achieved.
(71) Shandong University, Shandong 250061 (CN); China Power Construction Municipal Construction Group Co., Ltd, Tianjin 300451 (CN)