DATE: March 6, 2019
TIME: 1:00 pm to 2:00 pm EST
Continuing Education Credit: 0.1 CEU (1.0 PDH)
Approved AIA and ICC
Access Period: 30 days
CEU (PDH) REQUIREMENTS:
To earn CEU (PDH) credit, individuals must purchase the webinar and attend the live webinar for the entire duration (or pass the quiz available after the webinar).
Detailed Webinar Instructions
“Mix Design” is an interesting, challenging, and fundamental task. The objective is to predict the relative quantities of ingredients that will reliably and economically meet specifications and satisfy the needs of the concrete producer and contractor. A wide variety of “mix design” methods are used, varying from simple volumetric batching (by hand) of a 1:2:3 mix, to sophisticated, computer-based techniques, all of which are intended to produce a good-first-guess called a “trial mix.”
Then the trial mix has to be evaluated at lab- and field-scale, with the expectation of making adjustments based on continued monitoring of performance. In this test-and-adjust process, actual concrete performance matters more than the mix design method because there are no guarantees in mix-design, and each mixture must account for the characteristics and variability of local materials. Even though most concrete is batched by weight, a lot can be learned by looking at the relative volumes of paste, air, and aggregates. And regardless of the method, three key parameters that define concrete performance, i.e., water-content (defining workability), water-cement ratio (dictating strength and durability), and total cementitious materials (dictating cost, heat, chemical reactivity, and shrinkage-tendency) cannot be independently selected. At best the mix designer can independently select any two of the three, and accept the dependency of the third…or turn to admixtures and specialized aggregate grading.
Author: Ken Hover
Categories: Concrete Fundamentals, Design, Mixture Proportioning
Formats: Online Learning
Table of Contents
1. Recognize that efficient mixture design results in a trial mix that can be readily adjusted to efficiently meet required concrete performance, and that performance is more important than the mix design method.
2. Explain why the word “design” in the phrase “Mix Design” may not carry the same implications as use of the same word in the phrase “Structural Design.”
3. Discuss valuable insight to concrete performance by examining volumetric proportions, even though concrete is typically batched by weight.
4. Summarize the trade-offs in concrete properties in a conventional mixture, workability, w/c, and total cementitious materials content are not independent.
Any applicable errata are included with individual documents at the time of purchase. Errata are not included for collections or sets of documents such as the ACI Collection. For a listing of and access to all product errata, visit the
Printed / Hard Copy Products: The full and complete returned product will be accepted if returned within 60 days of receipt and in salable condition. A 20% service charge applies. Return shipping fees are the customer’s responsibility.
Electronic /Downloaded Products & Online Learning Courses: These items are not eligible for return.
Subscriptions These items are not eligible for return.
Exchanges: Contact ACI’s Customer Services Department for options (+1.248.848.3800 – ACICustomerService@concrete.org).