Cement mortar containing excavated soil prepared by replacing natural sand with engineering soil, and preparation method therefor and application thereof

Patent metadata

Field	Value
Publication number	US-2022033303-A1
Application number	US-201917279610-A
Country	US
Kind code	A1
Filing date	Oct 31, 2019
Priority date	Feb 25, 2019
Publication date	Feb 3, 2022
Grant date	—

Abstract

The present invention discloses cement mortar containing excavated soil prepared by replacing natural sand with engineering soil, and a preparation method therefor and an application thereof. The preparation method includes drying and grinding waste engineering soil taken from a construction site first, sieving and mixing it to form recycled engineering soil, and putting the recycled engineering soil and natural sand into a mortar mixer according to a certain proportion to form a sandy soil mixture; then pouring water and cement into the mortar mixer, adding a part of the sandy soil mixture and a part of a water-reducing admixture, and evenly stirring; and finally, adding the remaining sandy soil mixture and water-reducing admixture, and evenly stirring to obtain the cement mortar containing excavated soil.

First claim

1 . A preparation method for a cement mortar containing an excavated soil prepared by replacing a natural sand with an engineering soil, wherein the preparation method comprises the following steps:
(1) drying the engineering soil to a constant weight at a temperature of 105±5° C.; (2) sieving the dried engineering soil into A, B and C groups according to particle sizes; (3) putting the engineering soil of the C group obtained in the step (2) into a grinder to grind for 2 times to 3 times, with each grinding lasting for 3 seconds to 8 seconds; (4) sieving the ground engineering soil of the C group to obtain a sieved engineering soil; (5) mixing the sieved engineering soil obtained in the step (4) with the engineering soil of the B group to form a recycled engineering soil; (6) mixing the recycled engineering soil obtained in the step (5) with a sieved natural sand, adding into a mortar mixer, stirring to form a sandy soil mixture, and taking out the sandy soil mixture for later use; and (7) weighing water, cement, the sandy soil mixture and a water-reducing admixture; evenly dividing the sandy soil mixture and the water-reducing admixture into two parts, adding the water and the cement into the mortar mixer, and stirring to form a cement slurry; then adding one part of the sandy soil mixture and one part of the water-reducing admixture, and stirring; and then adding the other part of the sandy soil mixture and the other part of the water-reducing admixture, and stirring to prepare the cement mortar containing the excavated soil prepared by replacing the natural sand with the engineering soil.

2 . The preparation method according to claim 1 , wherein the engineering soil in the step (1) is a weathered soil of granite produced in a foundation engineering, an underground engineering and a subway construction.

3 . The preparation method according to claim 1 , wherein after sieving the dried engineering soil into the A, B and C groups according to the particle sizes in the step (2), a particle size of the sieved engineering soil of the A group is 0 mm to 0.25 mm, a particle size of the sieved engineering soil of the B group is 0.25 mm to 2.0 mm, and a particle size of the sieved engineering soil of the C group is greater than 2.0 mm.

4 . The preparation method according to claim 1 , wherein a motor speed of the grinder in the step (3) is 35000 r/min to 40000 r/min; and a particle size of the sieved engineering soil in the step (4) is 0.25 mm to 4.75 mm.

5 . The preparation method according to claim 1 , wherein the sandy soil mixture in the step (6) comprises the following raw materials in parts by mass:
30 parts to 70 parts of the recycled engineering soil; and 30 parts to 70 parts of the sieved natural sand; a particle size of the sieved natural sand is 0.25 mm to 4.75 mm.

6 . The preparation method according to claim 1 , wherein a stirring speed of the stirring in the step (6) is 60±10 r/min, and the stirring in the step (6) lasts for 1 minute to 3 minutes; and a stirring speed of the stirring in the step (7) is 60±10 r/min, and the stirring in the step (7) lasts for 1 minute to 2 minutes.

7 . The preparation method according to claim 1 , wherein the cement mortar containing the excavated soil prepared by replacing the natural sand with the engineering soil in the step (7) comprises the following raw materials in parts by mass:
212 parts to 275 parts of the water; 650 parts to 700 parts of the cement; 1600 parts to 1650 parts of the sandy soil mixture; and 10 parts to 80 parts of the water-reducing admixture.

8 . The preparation method according to claim 1 , wherein the cement in the step (7) is an ordinary Portland cement; and the water-reducing admixture in the step (7) is an aqueous solution of a polycarboxylate water-reducing admixture, with a mass percentage concentration of 8% to 12%.

9 . A cement mortar containing the excavated soil prepared by the preparation method according to claim 1 .

10 . An application of the cement mortar containing the excavated soil prepared by replacing the natural sand with the engineering soil according to claim 9 to a civil engineering.

Assignees

• Univ South China Tech

Inventors

• Wu Bo
• Cao Huixuan

Classifications

• C04B28/04 Primary

  Portland cements · CPC title

• C04B14/361 Primary

  Soil, e.g. laterite · CPC title

• C04B2111/60

  Flooring materials · CPC title

• C04B2103/302

  Water reducers · CPC title

• C04B28/02

  containing hydraulic cements other than calcium sulfates · CPC title