Batimix Silica Fume 710 U

Description

BATIMIX Silica Fume 710 is a powder silica fume mineral additive. It is used to produce high-performance concrete. It is available in two forms: BATIMIX Silica Fume 710 U, in an un-densified form with bulk density typically of 200 to 350 kg/m³, and BATIMIX Silica Fume 710 D, in a densified form with a bulk density of typically 450 to 700 kg/m³.

Main Purpose

When added to a concrete mix, the ultra-fine particles of BATIMIX Silica Fume 710 U significantly improve the particle packing, as they physically fill the voids in the cement paste. This leads to a more densified concrete skeleton, with reduced levels of bleeding. On the other hand, this product reacts chemically with the calcium hydroxide present in the cement paste, yielding a calcium silicate hydrate gel that significantly enhances strength, water/chloride impermeability, and durability.

BATIMIX Silica Fume 710 U is incorporated in a wide variety of high strength and specialty concrete mixtures. It is used to produce underwater, shotcrete, self-consolidating, and pre-stressed concrete. It is also used to improve the strength and reduce the sizing of structural sections of columns, retaining walls, bridges, dams, marine structures, and various structural elements.

Features

Concrete prepared with BATIMIX Silica Fume 710 is characterized by the following:

In the plastic state:

• Better cohesiveness with less bleeding and segregation
• Improved concrete pumping

In the hardened state:

• Increased compressive and flexural strengths at all ages
• Greatly reduced permeability against water and aggressive chemicals
• Increased resistance to abrasion and erosion
• Improved concrete durability and better surface quality

Properties

• Appearance : grey powder
• Bulk density : 200 to 350 kg/m³
• Amorphous SiO₂: 85 – 98%
• Average particle diameter: 0.1 – 0.15 micron

Health and Safety

BATIMIX Silica Fume 710 is not a hazardous material. However, it should not be breathed or allowed to come into contact with skin and eyes. Suitable gloves and goggles should be worn. For additional information, kindly refer to the product’s Material Safety Data Sheet.

Compliance with Standards

BATIMIX Silica Fume 710 U complies with ASTM C 1240.

Dosage Rates

BATIMIX Silica Fume 710 U is normally used at the rate of 5% to 12% of the cement weight, depending on the amount of strength increase and permeability reduction desired. Primarily trials tests are recommended using the actual mix composition with site materials, in particular if dosages greater than 10% of the cement weight are to be used.

Concrete containing BATIMIX Silica fume 710 U may be placed in the same manner as conventional concrete. However, special emphasis should be given to the finishing and curing operations. For example, silica fume makes the concrete more vulnerable to plastic shrinkage cracks due to the absence of bleeding associated with a rapid moisture loss from the concrete surface. In such a case, concrete should be promptly reworked and thoroughly covered with a wet burlap. On the other hand, proper curing methods such as continuous moist curing or liquid compound membranes should be implemented for a minimum of 7 days.

For indication purposes, the compressive strengths after 28 days of concrete made with 0.50 W/C and various percentages of 0%, 5%, and 10% of BATIMIX Silica Fume 710 U will vary from 35.4, 38.1, and 42.5 MPa, respectively.

Effect of overdosing

An overdose of BATIMIX Silica Fume 710 U will result in a highly sticky and viscous concrete with significantly reduced workability. This leads to greater amounts of superplasticizer for a given workability,which, in turn, may lead to some set retardation. Furthermore, the concrete may become difficult to finish requiring special finishing and curing procedures.

Compatibility

BATIMIX Silica Fume 710 U is compatible with all other Batimix admixtures incorporated in the same concrete. Concrete mixtures based on Portland cement with or without replacement materials such as fly ash and blast furnace slag are also fully compatible with BATIMIX Silica Fume 710 U.

Dispensing

BATIMIX Silica Fume 710 U is introduced in the concrete mixer in a similar manner and at the same time as Portland cement or any other cementitious material such as fly ash or blast furnace slag. Because of its ultra-fine particles, the mixing time should generally be increased to ensure effective dispersion throughout the mass concrete.

Technical Support

Holderchem provides, upon request, technical advisory services pertaining to concrete mix design, admixture selection, materials testing, and dispensing systems.

Storage

BATIMIX Silica Fume 710 U has a minimum shelf life of 12 months if kept unopened and stored at temperatures ranging from 2 to 50 ºC.

Packages

• 1 t big bag
• 25 kg paper bag