Air-entrained concrete is produced using air-entraining portland cement, or by the introduction of air-entraining agents, under careful engineering supervision, as the concrete is mixed on the job. The amount of entrained air is usually between four and seven percent of the volume of the concrete, but may be varied as required by special conditions.
Architectural concrete refers to concrete that while providing an aesthetic finish to the building also serves a structural function. Decorative concrete typically refers to concrete flatwork or building elements such as panels, that while enhanced with texture or color, are not structural building members.
Fiber reinforced concrete is a type of concrete that includes fibrous substances that increase its structural strength and cohesion. Fiber reinforced concrete has small distinct fibers that are homogeneously dispersed and oriented haphazardly.
High-performance concrete applications include roadway and bridge construction, tunnels, and tall buildings. The design of HPC for these projects is more about high density, low permeability, and resistance to the elements, than for compressive strength.
In the early 1970s, experts predicted that the practical limit of ready-mixed concrete would be unlikely to exceed a compressive strength greater than 11,000 pounds square inch (psi). Over the past two decades, the development of high-strength concrete has enabled builders to easily meet and surpass this estimate.
Hydrophobic concrete is concrete that repels water. It meets the standards outlined in the definition of waterproof concrete. Developed in Australia in the mid-20th century, millions of cubic yards of hydrophobic concrete have been laid in Australia, Asia, and Europe, and in the United States since 1999.
A structural light-weight concrete mix has a density of about 105 pounds per cubic foot compared to normal concrete with a density of 150 pounds per cubic foot. The light-weight concrete density is less because lightweight coarse aggregates and sometimes lightweight fine aggregates are used, which make the concrete weigh less.
Low Heat Cement is specially blended to provide a lower heat of hydration. in concrete. This unique attribute makes it ideal for mass concrete pours. where the rate of temperature rise and the maximum temperature achieved. must be controlled in order to reduce the risk of thermal cracking.
Normal concrete High Strength Concrete High Performance Concrete Air Entrained Concrete Light Weight Concrete Self Compacting Concrete Shotcrete Pervious Concrete Roller Compacted Concrete The concrete in which common ingredients i.e. aggregate, water, cement are used is known as normal concrete.
Schematic of a typical pervious concrete pavement section. When pervious concrete is used for paving, it can take in stormwater at a rapid rate of 3 to 5 gallons per minute per square foot of surface area, which exceeds the flow rate needed to prevent runoff in most rain events.
Portland Pozzolana Cement 1. Pozzolana. Pozzolana is a volcanic powder found in Italy near Vesuvius. A pozzolanic material is essentially a siliceous or aluminous material which possess no cementitious properties. But it has the property when it combined with lime to produce a stable pozzolana compound it has definite cementitious properties.
Self-consolidating concrete (SCC) is recognized as one of the greatest advances in the concrete industry over the past 20 years. Using new admixtures and some mix modifications, we can now produce concrete that flows easily without segregating (where the coarse aggregate separates from the cement paste).
One widely used specialty concrete is known as “shotcrete.” The major difference between shotcrete and its close cousin, concrete, is the placement method. Concrete is discharged from a ready-mix truck, placed on the ground or in forms and then must be vibrated for compaction.
ASTM's cement and concrete standards are instrumental in the evaluation and testing of concrete, cement, and aggregates. Concrete can have different properties depending upon the mixture that is used in creating it, which contains cement, chemical admixtures, and aggregates.
Sulfate Resisting Cement is a blended cement designed to improve the. performance of concrete where the risk of sulfate attack may be present. It also. provides improved durability for concrete in most aggressive environments, reducing the risk of deterioration of the structure and structural failure.