阅读说明：本技术 一种矿物掺合料及其应用 (Mineral admixture and application thereof ) 是由 李明辰 王腾飞 靳宏昌 于 2020-05-19 设计创作，主要内容包括：本发明涉及一种矿物掺合料及其应用,属于矿物掺合料及其应用技术领域。本发明的矿物掺合料,是将铸造尾废砂磨细至比表面积≥400㎡/kg制得的。本发明能将铸造尾废砂重新利用,变废为宝,大幅降低生产成本,有效增加混凝土的抗压强度。(The invention relates to a mineral admixture and application thereof, belonging to the technical field of mineral admixtures and application thereof. The mineral admixture is prepared by grinding waste foundry sand to specific surface area not less than 400 square meters per kg. The invention can reuse the waste sand from casting, changes waste into valuable, greatly reduces the production cost and effectively increases the compressive strength of concrete.)

1. A mineral admixture is characterized in that casting waste sand is ground until the specific surface area is more than or equal to 400 square meters per kg, and the mineral admixture is obtained.

2. Use of a mineral admixture according to claim 1 for the preparation of concrete products, comprising the steps of:

1) mixing the components

Uniformly mixing the mineral admixture and the concrete, wherein the mass ratio of the mineral admixture to the concrete is (0.8-7): (99.2-93);

2) steam curing

And (2) placing the mixture obtained in the step 1) in saturated steam for steam curing, and curing for 4-8 hours at a temperature of 65-95 ℃ in a non-pressure environment to obtain the concrete product.

3. The use of a mineral admixture according to claim 2, wherein the mass ratio of said mineral admixture to concrete in step 1) is 4.5: 95.5.

4. the use of a mineral admixture according to claim 1, wherein a secondary steam curing is carried out after the steam curing in step 2), wherein the secondary steam curing is carried out in a closed high-pressure container for 6 to 10 hours at a temperature of 150 ℃ to 170 ℃ and a constant pressure of 0.8 to 1 MPa.

Technical Field

The invention relates to a mineral admixture and application thereof, belonging to the technical field of mineral admixtures and application thereof.

Background

At present, mineral admixtures are more in variety, mineral powder, fly ash, silica fume, fine grinding sand and the like are commonly used, the application cost of the materials is higher, and the material cost is greatly increased. According to statistics, 1.2 tons of waste sand can be produced when one ton of qualified castings is produced in China, most of the waste sand is discarded except a small amount of waste sand is recycled, limited resources are greatly wasted, and serious environmental pollution can be caused, so that the utilization of the waste sand at the tail of casting becomes a problem which needs to be solved urgently in China.

Disclosure of Invention

The invention aims to solve the defects in the prior art and provide the mineral admixture which can recycle the waste foundry sand, change waste into valuable, greatly reduce the production cost and effectively increase the compressive strength of concrete and the application thereof.

The mineral admixture is characterized in that waste foundry sand is ground until the specific surface area is more than or equal to 400 square meters per kg, and then the mineral admixture is obtained;

the application of the mineral admixture is characterized in that the mineral admixture is used for preparing concrete products, and specifically comprises the following steps:

1) mixing the components

Uniformly mixing the mineral admixture and the concrete, wherein the mass ratio of the mineral admixture to the concrete is (0.8-7): (99.2-93);

the optimal mass ratio of the mineral admixture to the concrete is 4.5: 95.5;

2) steam curing

Placing the mixture obtained in the step 1) in saturated steam for steam curing, and curing for 4-8 hours in a non-pressure environment with the temperature controlled at 65-95 ℃;

and after the steam curing, continuously carrying out secondary steam curing, wherein the secondary steam curing is carried out by placing the mixture in a closed high-pressure container for curing for 6-10 hours, controlling the temperature at 150-170 ℃ and the constant pressure at 0.8-1.0 MPa.

The mineral admixture can effectively improve the compressive strength of concrete, and the main chemical component of the casting tailing sand is SiO through detection₂The content of the admixture is about 80 percent, after the admixture is doped into concrete, the alkalinity of the concrete can be improved, the alkalinity protection of reinforcing steel bars is facilitated, and SiO in the admixture under the condition of high-pressure maintenance₂Can rapidly generate chemical reaction with CaO to generate hydrated calcium silicate, and the admixture changes the hydration process of cement, namely, the admixture hinders C₆S₂H₃And Ca (OH)₂The tobermorite with good crystallization is formed, the internal pores are reduced, the compactness is improved, the compressive strength is high, the dimensional stability is good, and the durability is good.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.