Details:

Creators:
Trejo, David ; Chen, Jiaming
Trejo, David ; Chen, Jiaming Less -
Corporate Creators:
Oregon State University
Corporate Contributors:
United States. Federal Highway Administration
Subject/TRT Terms:
[+]
Admixtures Aggregates Concrete Mixing Drums (Containers) Durability Mechanical Properties Ready Mixed Concrete Specifications Workability
Publication/ Report Number:
WA-RD 831.1
Resource Type:
Tech Report
Geographical Coverage:
Washington
Corporate Publisher:
Washington (State). Dept. of Transportation. Research Office
Abstract:
Specifications for ready-mixed concrete limit drum revolution and mixing time to 250 drum revolutions and/or

1.5 hours before discharge. These specifications have been in place for many years with the objective of ensuring

the quality and performance of the finished concrete product; however, these limitations could potentially increase

construction costs without additional benefits, especially when longer transport distances are required. Because

there have been significant changes in concrete constituent materials (e.g., chemical admixtures) and equipment

since these limits were first implemented, research is needed to assess the effects of time to discharge and drum

revolution counts on concrete performance. The objective of this research program is to evaluate and verify

whether existing specifications for mixing and transporting concrete are applicable for today’s materials and

equipment and if not, to identify key variables or tests that can ensure adequate placeability and good mechanical

and durability characteristics. This study evaluated the influence of coarse and fine aggregate, supplementary

cementitious materials quantity and type, chemical admixtures, temperature and mixing time and drum revolution

on the mechanical and durability characteristics of concrete. Results indicate that existing specifications may be

appropriate due to loss of workability. However, mixing time and drum revolution counts had no significant effects

on the majority of mechanical properties and durability characteristics of ready-mixed concrete and results from

this research indicate that existing specification limits are very conservative.


Format:
PDF
Funding:
GCA 6766
Collection(s):
US Transportation Collection
Main Document Checksum:
[+]
urn:sha256:f7b1623c5a0fe331b46930472eb4a8f93811dfb55d1a0b5edb03dd61c9c974ce
Download URL:
https://rosap.ntl.bts.gov/view/dot/28842/dot_28842_DS1.pdf
File Type:

Supporting Files

• No Additional Files

More +