Name: concrete fillers that improve performance
Uploaded: 2024-11-07T14:48:38.000Z
Duration: 1 min 29 s
Channel: JoVE

충전제와 첨가제는 포틀랜드 시멘트와 유사한 섬도를 가진 미세한 입자 재료입니다.
시멘트질 첨가제로 사용되는 포졸란(Pozzolalan)과 용광로 슬래그(blast-furnace slag)는 시공성, 밀도 등의 콘크리트 품질을 향상시키는 동시에 블리딩(bleeding)과 균열(cracking)을 줄인다.
충전제는 탄산칼슘을 형성하는 핵형성 지점을 제공하여 포틀랜드 시멘트의 수화 과정을 촉진할 수 있습니다. 이러한 핵형성 부위는 비산회와 이산화티타늄 입자가 있는 콘크리트에서 관찰됩니다.
탄산칼슘은 규산칼슘 수화물 상과 합쳐져 일단 수화되면 시멘트 페이스트의 구조를 유리하게 변경합니다.
필러는 천연 또는 가공 된 무기 물질에서 파생 될 수도 있으며 주로 수화 석회 또는 응집체 먼지와 같은 물리적 효과를 발휘합니다.
일반적으로 이러한 충전재는 그라우트 및 석조 모르타르에서 작업성 향상제 역할을 합니다. 색상 안료는 또한 불활성 첨가물로 간주됩니다.
분말 아연 또는 알루미늄이 수산화칼슘의 존재 하에 도입되면 수소 가스가 생성됩니다. 가스 형성 혼화제로 알려진 이러한 물질은 폭기 콘크리트를 만듭니다.
또 다른 예로, 과산화수소는 모래-시멘트 혼합물 내에 남아 있는 산소 기포를 방출하여 폭기된 콘크리트를 생성합니다.

콘크리트의 첨가제와 충전제

첨가제와 충전제는 콘크리트의 특성을 강화하는 데 필수적입니다. 포졸란과 고로 슬래그는 시멘트 수화 중에 발생되는 수산화칼슘과 반응하여 첨가제 또는 혼화제가 됩니다. 미세하게 분쇄되고 포틀랜드 시멘트와 유사한 미세도를 가진 충전제는 작업성 밀도와 같은 콘크리트 속성을 개선하고 모세관 블리딩 또는 균열을 줄입니다. 일부 충전제는 유압 특성을 가지고 있거나 시멘트 페이스트 내에서 양성 반응에 참여합니다.


 충전제의 역할은 포틀랜드 시멘트 수화를 촉진하여 핵형성 부위를 제공하는 것입니다. 플라이애시와 이산화티타늄이 종종 이 역할을 담당하며, 최종 시멘트 페이스트의 미세 구조에 기여합니다. 충전제는 천연이거나 가공된 것일 수 있으며, 일관된 특성, 특히 미세함을 가질 수 있습니다. 충전제는 물의 수요를 증가시키거나 콘크리트의 내구성과 강도에 부정적인 영향을 미쳐서는 안 됩니다.


 충전제와 첨가제는 대부분 시멘트와 물리적으로 혼합되며 사용되어야 합니다. 예를 들어, 일부 매우 미세한 시멘트 입자는 초기 강도에 필수적입니다. 수화 석회 또는 정상 중량 골재와 같은 불활성 물질은 강도가 아닌 작업성을 개선하기 위해 추가됩니다. 알칼리 또는 수산화칼슘이 존재할 때 수소를 방출하는 첨가제는 가스 콘크리트 또는 기포 콘크리트를 만드는 데 사용되어 열 절연을 제공합니다. 과산화수소와 같은 가스 형성 혼합물은 기포 콘크리트 혼합물에서 산소 거품을 생성합니다.

충전제와 첨가제는 포틀랜드 시멘트와 유사한 섬도를 가진 미세한 입자 재료입니다.
Pozzolans 및 용광로 슬래그는 시멘트질로 사용됩니다 ...

Education

교육

JoVE Core

Civil Engineering

토목공학

Unit 1

제1단원

Admixtures

혼화제

KEY TERMS AND CONCEPTS

주요 용어 및 개념

Additives and Fillers in Concrete

concrete fillers that improve performance

Concrete fillers and additives help change how cement paste performs. Pozzolans and blast-furnace slag act as additives or admixtures because they react with calcium hydroxide released during cement hydration. Fine fillers are close in fineness to Portland cement and can improve workability, density, and resistance to capillary bleeding or cracking.

Some fillers are hydraulic, which means they can react with water, while others take part in harmless reactions inside the cement paste. A key role of many fillers is to support Portland cement hydration by giving the paste nucleation sites, or places where new crystals can start forming. Fly ash and titanium dioxide can play this role and help shape the microstructure of the hardened cement paste.

Fillers may be natural or processed, but they should have steady properties, especially fine particle size. They should not raise the water demand of the mix or reduce durability and strength. In concrete, fillers and additives are usually mixed in physically, so they must be compatible with the cement system.

Very fine cement particles can also matter for early strength. Inert materials such as hydrated lime or normal-weight aggregates may be added to improve workability rather than strength. Some additives release hydrogen in the presence of alkalis or calcium hydroxide and are used to make gas concrete, also called aerated concrete, which provides thermal insulation. Gas-forming admixtures such as hydrogen peroxide can create oxygen bubbles in aerated concrete mixes.

Concrete Fillers That Improve Performance

concrete-fillers-that-improve-performance

accelerators

Calcium Chloride in Concrete Mixes

Calcium chloride is a concrete admixture that speeds up hardening and helps concrete gain early strength faster. It does not always change the setting time itself, but it can reduce the time needed in practice. This makes it useful in cold weather and in rapid repair work where quick heat generation after mixing is helpful. A common amount is 1 to 2 percent of the cement mass. Its effect can be compared with raising the concrete temperature by 11 degrees Fahrenheit. To spread it evenly through...

retarders

Retarders in Concrete Pouring

Retarders are chemical admixtures used in concrete to slow the setting time. They are especially helpful when one pour must follow another after a delay. By keeping the concrete workable for longer, they can help prevent cold joints and support a more cohesive structure. Retarders can also improve the look of exposed aggregate finishes when they are used in the right amount. Their effect on setting time can be checked with a penetration test. Common retarding substances include sugar,...

plasticizers

Concrete Workability with Plasticizers

Concrete plasticizers are water-reducing chemical admixtures that improve workability and strength. They help concrete use less water while keeping the same flow, reduce cement content without losing workability, or make mixes easier to place in hard-to-reach areas. Plasticizers work by using surface-active agents. These agents create repulsive electrostatic forces between cement particles. The particles disperse more evenly, and the concrete needs about 5 to 15 percent less mixing water. <br...

superplasticizers

Superplasticizers for Stronger Concrete Mixes

Superplasticizers are concrete admixtures that make mixes flow better while using less water. They are strong water reducers, so concrete can be easier to place without losing strength. This makes them useful when concrete must reach tight spaces or heavily reinforced areas without mechanical vibration. These admixtures work through sulfonated melamine or naphthalene formaldehyde condensates. These chemicals give cement particles a negative charge. The particles repel each other and spread out...

additives and fillers in concrete

Concrete fillers and additives help change how cement paste performs. Pozzolans and blast-furnace slag act as additives or admixtures because they react with calcium hydroxide released during cement hydration. Fine fillers are close in fineness to Portland cement and can improve workability, density, and resistance to capillary bleeding or cracking. Some fillers are hydraulic, which means they can react with water, while others take part in harmless reactions inside the cement paste. A key...

waterproofing and anti-bacterial admixtures in concrete

waterproofing-and-anti-bacterial-admixtures-in-concrete

Concrete Water Resistance and Biological Protection

Concrete can absorb water because of capillary action in the pores of its hydrated cement paste. That movement pulls water into the material. Waterproofing admixtures are added to reduce this penetration and help concrete resist water. The effect of a waterproofing admixture depends on the water pressure acting on the concrete. Rain, capillary rise, and hydrostatic pressure in structures made to hold water can all affect performance. These admixtures make concrete hydrophobic, which means they...

key terms and concepts

Learn how concrete fillers and additives affect workability, density, early strength, cracking, and aerated concrete through simple, science-based examples.

Concrete Fillers That Improve Performance | JoVE K12

JoVE Core Civil Engineering offers a foundational exploration of essential construction materials such as bricks, stones, steel, wood, and concrete, along with fluid mechanics topics like flow over immersed bodies, open channel flow, and dimensional modeling. It also covers key surveying concepts, including leveling, traverse adjustments, curve design, topographic mapping, and geospatial technologies (GPS & GIS). Science-in-action videos showcase laboratory research on materials, fluids, and surveying practices in real-world engineering systems.

civil engineering

Concrete Fillers That Improve Performance

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