High-strength concrete and preparation method thereof

Abstract

The present disclosure relates to a high-strength concrete and a preparation method thereof. The high-strength concrete includes lignin, recycled fine powder, cement, water, sand, gravels and a water reducing agent. The recycled fine powder is recycled fine powder of discarded concrete, and is prepared by separating solid waste of discarded buildings, then performing impurity removal and crushing processing, and grinding same by a ball mill into dust with a particle size of less than 0.16 mm. The lignin is discarded wood lignin, which is prepared by crushing the wood, stirring and extracting a sodium hydroxide aqueous solution with a mass concentration of 5% for 1 to 2 hours at the temperature of 80 DEG C. to obtain a black lignin alkali solution, adding a hydrochloric acid solution with a mass concentration of 30% into the alkali solution for stirring, and making the pH reduced to 7.0 for standing and layering.

Claims

1. A concrete comprising lignin, recycled fine powder, P.042.5 grade cement, water, sand, gravels with a particle size of 6 mm to 10 mm, and a polycarboxylic acid water reducing agent; wherein a weight ratio of the cement, water, sand, gravels and the polycarboxylic acid water reducing agent in the concrete is 1:0.3:1.2:2.8:0.01; a weight ratio of the lignin to the cement in the concrete is 0.1-0.3:20; a weight ratio of the lignin to the recycled fine powder in the concrete is 0.1:5-10; the recycled fine powder is recycled powder of discarded concrete, and is prepared by: separating solid waste of discarded buildings, removing impurity and crushing, and grinding into dust with a particle size of less than 0.16 mm by a ball mill; the lignin is discarded wood lignin, which is extracted by: crushing wood, stirring and extracting with a sodium hydroxide aqueous solution with a mass concentration of 5% for 1 to 2 hours at 80° C. to obtain a black lignin alkali solution, adding a hydrochloric acid solution with a mass concentration of 30% into the black lignin alkali solution while stirring, reducing pH to 7.0, and obtaining the lignin by standing and layer separation; and the concrete is made by a method comprising the following steps: (1) pouring the lignin and the recycled fine powder into a portion of water to obtain a first uniformly mixed mixture, (2) pouring the cement into the remaining water with a cement mixer to obtain a second uniformly mixed mixture, (3) pouring the first uniformly mixed mixture into the second uniformly mixed mixture to obtain a third mixture, and then adding the polycarboxylic water reducing agent to the third mixture to obtain a uniformed mixed mixture A, and (4) pouring the gravels and sand into the uniformly mixed mixture A for thoroughly stirring to obtain the concrete.

2. The concrete of claim 1, wherein a ratio of water in the step (1) and step (2) is 1:2.

Description

DETAILED DESCRIPTION

(1) The present disclosure will be further described below with reference to specific embodiments, and the advantages and characteristics of the present disclosure will become clear from the description. However, the embodiments are only exemplary and do not constitute any limitation to the scope of the present disclosure. It should be understood by those skilled in the art that modifications and replacements may be made to the details and forms of the technical solutions of the present disclosure without departing from the spirit and scope of the present disclosure, and all these modifications and replacements shall fall within the protection scope of the present disclosure.

(2) Embodiment One: A High-Strength Concrete and a Preparation Method Thereof.

(3) At step 1, P⋅042.5 grade cement is adopted, gravels with a particle size of 6 m to 10 m are adopted, and a polycarboxylic acid water reducing agent is adopted; preparation of recycled fine powder: separating solid waste of discarded buildings, then performing impurity removal and crushing processing, and grinding same by a ball mill into dust with a particle size of less than 0.16 m; and preparation of lignin: crushing the wood, stirring and extracting a sodium hydroxide aqueous solution with a mass concentration of 5% for 1 to 2 hours at the temperature of 80 DEG C. to obtain a black lignin alkali solution, adding a hydrochloric acid solution with a mass concentration of 30% into the alkali solution for stirring, and making the pH reduced to 7.0 for standing and layering to obtain the lignin.

(4) At step 2, 20 kg of cement, 6 kg of water, 24 kg of sand, 56 kg of gravels, and 0.2 kg of water reducing agent are weighted using a meter.

(5) At step 3, 0.1 kg of lignin and 10 kg of recycled fine powder are poured into 2 kg of water for uniform mixing.

(6) At step 4, 20 kg of cement is poured into 4 kg of water for full stirring with a cement mixer.

(7) At step 5, the mixed solution of lignin and recycled fine powder is poured into the cement stirred uniformly in step 4, then 0.2 kg of water reducing agent is added for uniform mixing to obtain a mixed solution A.

(8) At step 6, 56 kg of gravels and 24 kg of sand are poured into the mixed solution A in step 5 for full stirring to obtain the high-strength concrete.

(9) Embodiment Two: A High-Strength Concrete and a Preparation Method Thereof

(10) At step 1, P⋅042.5 grade cement is adopted, gravels with a particle size of 6 mm to 10 mm are adopted, and a polycarboxylic acid water reducing agent is adopted; preparation of recycled fine powder: separating solid waste of discarded buildings, then performing impurity removal and crushing processing, and grinding same by a ball mill into dust with a particle size of less than 0.16 mm; and preparation of lignin: crushing the wood, stirring and extracting a sodium hydroxide aqueous solution with a mass concentration of 5% for 1 to 2 hours at the temperature of 80 DEG C. to obtain a black lignin alkali solution, adding a hydrochloric acid solution with a mass concentration of 30% into the alkali solution for stirring, and making the pH reduced to 7.0 for standing and layering to obtain the lignin.

(11) At step 2, 20 kg of cement, 6 kg of water, 24 kg of sand, 56 kg of gravels, and 0.2 kg of water reducing agent are weighted using.

(12) At step 3, 0.2 kg of lignin and 12 kg of recycled fine powder are poured into 1.5 kg of water for uniform mixing.

(13) At step 4, 20 kg of cement is poured into 4.5 kg of water for full stirring with a cement mixer.

(14) At step 5, the mixed solution of lignin and recycled fine powder is poured into the cement stirred uniformly in step 4, and then 0.2 kg of water reducing agent is added for uniform mixing to obtain a mixed solution A.

(15) At step 6, 56 kg of gravels and 24 kg of sand are poured into the mixed solution A in step 5 for full stirring to obtain the high-strength concrete.

(16) Embodiment Three: A High-Strength Concrete and a Preparation Method Thereof

(17) At step 1, P⋅042.5 grade cement is adopted, gravels with a particle size of 6 mm to 10 mm are adopted, and a polycarboxylic acid water reducing agent is adopted; preparation of recycled fine powder: separating solid waste of discarded buildings, then performing impurity removal and crushing processing, and grinding same by a ball mill into dust with a particle size of less than 0.16 mm; and preparation of lignin: crushing the wood, stirring and extracting a sodium hydroxide aqueous solution with a mass concentration of 5% for 1 to 2 hours at the temperature of 80 DEG C. to obtain a black lignin alkali solution, adding a hydrochloric acid solution with amass concentration of 30% into the alkali solution for stirring, and making the pH reduced to 7.0 for standing and layering to obtain the lignin.

(18) At step 2, 20 kg of cement, 6 kg of water, 24 kg of sand, 56 kg of gravels, and 0.2 kg of water reducing agent are weighted using a meter.

(19) At step 3, 0.3 kg of lignin and 15 kg of recycled fine powder are poured into 2 kg of water for uniform mixing.

(20) At step 4, 20 kg of cement is poured into 4 kg of water for full stirring with a cement mixer.

(21) At step 5, the mixed solution of lignin and recycled fine powder is poured into the cement stirred uniformly in step 4), and then 0.2 kg of water reducing agent is added for uniform mixing to obtain a mixed solution A.

(22) At step 6, 56 kg of gravels and 24 kg of sand are poured into the mixed solution A in step 5 for full stirring to obtain the high-strength concrete.

Experimental Example One: Axial Compression Experiment

(23) Experimental Steps:

(24) In the axial compressive strength experiment, a 150 mm*150 mm*300 mm prismatic specimen is used and standardly cured to a specified age. The specimen is placed upright, with the axis of the specimen aligned with the center of a lower platen of a testing machine, and load is applied at a specified speed until a failure, so as to measure its axial compressive strength. The experimental results are shown in Table 1:

(25) TABLE-US-00001 TABLE 1 Specimen Group Number Compressive Strength (MPa) Plain concrete 33.10 High-strength concrete obtained in 37.62 Embodiment one High-strength concrete obtained in 37.79 Embodiment two High-strength concrete obtained in 38.29 Embodiment three

(26) Experimental Results:

(27) By means of the axial compressive strength experiment of plain concrete and the concrete obtained by the present disclosure respectively, the experimental results show that the high-strength concrete obtained by the present disclosure has a significant increase in the compressive strength.