Structural Concrete – Lightweight STRUCTURAL CONCRETE – LIGHTWEIGHT
Part 1 — General
1.1 Section Includes
A.Structural lightweight concrete using lightweight aggregate for the coarse aggregate portion of the mix.
1.2 Related Sections
A.Section 03055: Portland Cement Concrete
1.3 References
A.AASHTO M 195: Lightweight Aggregates for Structural Concrete
B.AASHTO T 104: Soundness of Aggregate by Use of Sodium Sulfate or Magnesium Sulfate
C.AASHTO T 121: Density (Unit Weight), Yield, and Air Content (Gravimetric) of Concrete
D.AASHTO T 196: Air Content of Freshly Mixed Concrete by the Volumetric Method
E.ASTM C 567: Determining Density of Structural Lightweight Concrete
F.UDOT Minimum Sampling and Testing Requirements
1.4 Definitions
A.Structural Lightweight Concrete – A lightweight P ortland Cement Concrete mix (used to reduce the dead load of the structure ) with all of the attributes and performance equal to normal weight structural concrete and with a lower unit weight. Structural Concrete – Lightweight
1.5 Submittals
A.Refer to Section 03055 , except as modified in this Section.
1.Include in the concrete mix design submittal in addition to the requirements in Section 03055:
a.The weight and absolute volume for each component.
b.The unit weight of the fresh concrete mix for the purposes of acceptance.
c.Test reports showing that the equilibrium density of the concrete mix meet s the requirements of this Section, Article
2.1 Paragraph B.
1.6 Acceptance
A.Acceptance is accord ing to Section 03055 and the UDOT Minimum Sampling and Testing Requirements .
1.Air content will be determined by AASHTO T 196.
2.Density /unit weight of fresh concrete with each air content determination. Refer to AASHTO T 121.
Part 2 — Products
2.1 General
A.Refer to Section 03055 , except as modified in this Section.
B.Keep the equilibrium density of the mix between 110 to 115 lb/ft 3 as determined according to ASTM C 567.
C.Do not allow the unit weight of the fresh concrete to vary more than ± 4 lb/ft 3 from the target density for fresh concrete established by the mix design for field acceptance.
D.Aggregates
1.Coarse Aggregate
a.Meet the requirements of AASHTO M 195. 1) Meet AASHTO M 195 Table 1, gradation band ½ inch to #4 or ¾ inch to #4.
b.Use lightweight aggregates that have not more than 5 percent loss, when tested for soundness using Magnesium Sulfate (5 cycles). Refer to AASHTO T 104. Structural Concrete – Lightweight
E.Mix Design
1.Base the mix design on the recommendations of the lightweight aggregate manufacturer for each combination of materials to be used.
F.Aggregate Stockpiles
1.Uniformly pre -wet or pre- saturate the aggregates in such a manner that uniform penetration of the concrete will be maintained.
G.Batch Materials
1.Batch lightweight coarse aggregate either by weight or by volume. Equip the batching equipment if by volume such that the weight of each size of aggregate in the batch can be verified.
2.Verify each load using batched weights of materials.
Part 3 — Execution
3.1 General
A.Refer to Section 03055.
Source: Utah Standard Specifications for Road and Bridge Construction, 2026 Edition. Pages 901–903 of 1,331.