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A5.405.5 Cement and Concrete

California Green Building Standards Code 2019 > A5 Nonresidential Voluntary Measures > A5.405 Material Sources > A5.405.5 Cement and Concrete

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Use cement and concrete made with recycled products and complying with the following sections.

A5.405.5.1 Cement

Cement shall comply with one of the following standards:

Portland cement shall meet ASTM C150, Standard Specification for Portland Cement.
Blended cement shall meet ASTM C595, Standard Specification for Blended Hydraulic Cement or ASTM C1157, Standard Performance Specification for Hydraulic Cement.
Other Hydraulic Cements shall meet ASTM C1157, Standard Performance Specification for Hydraulic Cement.

Unless otherwise directed by the Engineer of Record, use concrete manufactured with cementitious materials in accordance with Sections A5.405.5.2.1 and A5.405.5.2.1.1, as approved by the enforcing agency.

A5.405.5.2.1 Supplementary Cementitious Materials (SCM)

Use concrete made with one or more supplementary cementitious materials (SCM) conforming to the following standards:

Fly ash conforming to ASTM C618, Specification for Coal Fly Ash and Raw or Calcined Natural Pozzolan for Use in Concrete.
Slag cement (GGBFS) conforming to ASTM C989, Specification for Use in Concrete and Mortars.
Silica fume conforming to ASTM C1240, Specification for Silica Fume Used in Cementitious Mixtures.
Natural pozzolan conforming to ASTM C618, Specification for Coal Fly Ash and Raw or Calcined Natural Pozzolan for Use in Concrete.
Blended supplementary cementitious materials conforming to ASTM C1697, Standard Specification for Blended Supplementary Cementitious Materials. The amount of each SCM in the blend will be used separately in calculating Equation A5.4-1. If Class C fly ash is used in the blend, it will be considered to be "SL" for the purposes of satisfying the equation.

Ultra-fine fly ash (UFFA) conforming to ASTM C618, Specification for Coal Fly Ash and Raw or Calcined Natural Pozzolan for Use in Concrete and the following chemical and physical requirements:

Chemical Requirements	Percent
Sulfur Trioxide (SO₃)	1.5 max.
Loss on ignition	1.2 max.
Available Alkalies (as Na₂O) equivalent	1.5 max.
Physical Requirements	Percent
Particle size distribution
Less than 3.5 microns	50
Less than 9.0 microns	90
Strength Activity Index with portland cement
7 days	95 (minimum % of control)
28 days	110 (minimum % of control)
Expansion at 16 days when testing job materials in conformance with ASTM C1567*	0.10 max.

* In the test mix, cement shall be replaced with at least 12% UFFA by weight.

Metakaolin conforming to ASTM C618, Specification for Coal Fly Ash and Raw or Calcined Natural Pozzolan for Use in Concrete, the following chemical and physical requirements:

Chemical Requirements	Percent
Silicon Dioxide (SiO₂) + Aluminum Oxide (Al₂O₃)	92.0 min.
Calcium Oxide (CaO)	1.0 max.
Sulfur Trioxide (SO₃)	1.0 max.
Loss on ignition	1.2 max.
Available Alkalies (as Na₂O) equivalent	1.0 max.
Physical Requirements	Percent
Particle size distribution
Less than 45 microns	95
Strength Activity Index with portland cement
7 days	100 (minimum % of control)
28 days	100 (minimum % of control)

Other materials with comparable or superior environmental benefits, as approved by the Engineer of Record and enforcing authority.

A5.405.5.2.1.1 Mix Design Equation

Use any combination of one or more SCM, satisfying Equation A5.4-14. When ASTM C595 or ASTM C1157 cement is used, the amount of SCM in these cements shall be used in calculating Equation A5.4-14.

Exception: Minimums in mix designs approved by the Engineer of Record may be lower where high early strength is needed for concrete products or to meet an accelerated project schedule.

(Equation A5.4-14)

where:

F	=	Fly ash, natural pozzolan or other approved SCM as a percent of total cementitious material for concrete on the project.
SL	=	GGBFS, as a percent of total cementitious material for concrete on the project.
UF	=	Silica fume, metakaolin or UFFA, as a percent of total cementitious material for concrete on the project.

A5.405.5.3 Additional Means of Compliance

Any of the following measures shall be permitted to be employed for the production of cement or concrete, depending on their availability and suitability, in conjunction with Section A5.405.5.2.

A5.405.5.3.1 Cement

The following measures shall be permitted to be used in the manufacture of cement.

A5.405.5.3.1.1 Alternative Fuels

The use of alternative fuels where permitted by state or local air quality standards.

A5.405.5.3.1.2 Alternative Power

Alternate electric power generated at the cement plant and/or green power purchased from the utility meeting the requirements of Section A5.211.

A5.405.5.3.2 Concrete

The following measures shall be permitted to be used in the manufacture of concrete.

A5.405.5.3.2.1 Alternative Energy

Renewable or alternative energy meeting the requirements of Section A5.211.

A5.405.5.3.2.2 Recycled Aggregates

Concrete made with one or more of the following materials:

Blast furnace slag as a lightweight aggregate in unreinforced concrete.
Recycled concrete that meets grading requirements of ASTM C33, Standard Specification for Concrete Aggregates.
Other materials with comparable or superior environmental benefits, as approved by the engineer and enforcing authority.

A5.405.5.3.2.3 Mixing Water

Water recycled by the local water purveyor or water reclaimed from manufacturing processes and conforming to ASTM C1602, Standard Specification for Mixing Water Used in the Production of Hydraulic Cement Concrete.

A5.405.5.3.2.4 High Strength Concrete

Concrete elements designed to reduce their total size compared to standard 3,000 psi concrete, thereby reducing the total volume of cement, aggregate and water used on the project, as approved by the Engineer of Record.