Application of superfine calcium carbonate filler in concrete

Abstract

The invention discloses an application of a superfine calcium carbonate filler in concrete. The doping amount of the superfine calcium carbonate filler is 5-15% of the total mass of a cementing material. The superfine calcium carbonate filler is a simple filler or a cheap substitute, and becomes an efficient performance regulator and reinforcing agent in modern concrete. Through triple effects of filling, crystal nucleus and chemistry, the early strength, the compactness and the durability of the concrete are remarkably improved at relatively low cost, and the concrete is one of important technical approaches for realizing high performance and greenization of the concrete and reducing the cement consumption.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of concrete, in particular to the application of superfine calcium carbonate filler in concrete. BACKGROUND

[0002] Research has found that superfine calcium carbonate filler plays a more delicate and complex role in concrete. It is not just a simple filler, but an important functional mineral admixture that significantly improves the performance of concrete from mixing to hardening through physical and chemical synergies. SUMMARY

[0003] The purpose of the present application is to provide the application of superfine calcium carbonate filler in concrete to solve the technical problems of concrete addition.

[0004] To achieve the above purpose, the following technical solutions are adopted in the present application: The application of superfine calcium carbonate filler in concrete, the content of superfine calcium carbonate filler is 5%-15% of the total mass of cementitious materials.

[0005] Compared with the prior art, the present application has the following advantages: superfine calcium carbonate filler has become a high-performance performance regulator and enhancer in modern concrete from a simple filler or cheap substitute. It significantly improves the early strength, density and durability of concrete at relatively low cost through the triple action of filling, nucleation and chemistry, and is one of the important technical approaches to realize the high performance and green of concrete and reduce the cement consumption. DETAILED DESCRIPTION

[0006] The present application will be further described in detail below in combination with specific examples.

[0007] The application of superfine calcium carbonate filler in concrete, the content of superfine calcium carbonate filler is 5%-15% of the total mass of cementitious materials.

[0008] Superfine calcium carbonate (usually refers to powder with particle size less than 10 μm) mainly plays the following three mechanisms: Microaggregate filling effect (physical core), space optimization: superfine particles can fill the voids between cement particles, making the particle size distribution of the cementitious system more continuous.

[0009] Pore refinement: More importantly, it can fill the smaller nanoscale pores between cement hydration products (such as C-S-H gel), thereby significantly reducing the total porosity of concrete and optimizing the pore structure, reducing harmful large pores and increasing harmless small pores.

[0010] Direct effect: significantly improves the density of concrete.

[0011] Crystal nucleus effect (Chemical-Physical Core) The superfine calcium carbonate particles provide a large number of evenly distributed "nucleation sites" for the precipitation and crystallization of cement hydration products (such as C-S-H gel and calcium hydroxide CH). This promotes the more uniform and dense growth of hydration products, rather than just forming a loose coating layer on the surface of the cement particles. Direct effect: accelerate the cement hydration reaction, especially beneficial to the development of early strength, and form a more uniform and stronger microstructure.

[0012] .

[0013] These new hydration products also help to fill pores and contribute to the growth of early strength.

[0014] High-performance concrete (HPC) and ultra-high-performance concrete (UHPC): As a key component, it is one of the essential materials for formulating UHPC to achieve the "closest packing of particles" theory, in order to obtain extremely high strength and durability.

[0015] Early strength concrete: used in precast components, rapid construction, low temperature construction, repair engineering and other occasions that require early demolding or bearing.

[0016] Self-compacting concrete (SCC): helps to adjust the rheological properties, while ensuring high fluidity, improves the segregation resistance and stability.

[0017] High durability concrete: used in harsh environments such as harbor engineering, cross-sea bridge, salt-frozen area, underground engineering and other infrastructure.

[0018] Composite cementitious material system: combined with fly ash, mineral powder and other active admixtures, it can "complement each other's advantages" and effectively compensate for the low early strength of these materials.

[0019] At the same fluidity, the amount of water reducing agent can be slightly reduced. The huge specific surface area will adsorb more water, which may cause the viscosity to increase, and excessive use may cause loss of slump. It needs to be compounded with high-efficiency water reducing agent.

[0020] Newly mixed concrete improves workability, and the "ball bearing effect" of superfine particles can improve fluidity. Hardened concrete significantly improves early strength. Crystal nucleus effect and chemical effect together accelerate hydration, greatly increase 3-day and 7-day strength. The filling effect and hydration development continue to improve long-term strength, and have stable gain in 28-day and later strength. Greatly enhance durability Improved density Bring: high impermeability: effectively block the invasion of chloride ions, water and harmful gases. Improve frost resistance: refine the pores to reduce the content of frozen water. Delay carbonation: dense structure hinders Diffusion. The influence of shrinkage and cracking can slightly increase early autogenous shrinkage, but overall it is beneficial to control drying shrinkage and cracking due to reduced water usage and optimized structure.

[0021] Optimum dosage: "Too much is not a good thing". Dosage is not the higher the better, usually 5% - 15% of the total mass of cementitious materials. Excessive dosage will lead to performance decline and poor economy due to the large increase in water demand and cementitious material "dilution effect".

[0022] The above describes the preferred embodiments of the present application. For those skilled in the art, according to the teachings of the present application, changes, modifications, replacements and variations made to the embodiments without departing from the principles and spirits of the present application still fall within the protection scope of the present application.

Claims

1. Use of ultrafine calcium carbonate filler in concrete, characterized in that, The content of the superfine calcium carbonate filler is 5% to 15% of the total mass of the cementitious material.