OasisLMS

The differences between lateral formwork pressure experienced when using self-consolidating concrete (SCC) versus conventionally vibrated concrete (CVC) will be covered in this course. The transitional boundaries between these two concrete categorizations will also be covered to some extent. The investigation of SCC formwork pressure over the past couple of decades has opened a wider discussion regarding the significance of concrete rheology (cementing materials dispersion and agglomeration-reversible properties) on formwork pressure development and decay (versus setting, hardening or irreversible properties). Models will be covered that use yield stress, viscosity, and thixotropy as important input parameters to predict lateral formwork pressure, while emphasizing the relevance of the traditional input parameters of concrete temperature and placement rate. The presentations will review and discuss existing pressure prediction models for both types of concrete and the means of characterizing concrete for lateral pressure. The purpose of the course is to establish a path forward for both SCC and CVC with respect to load calculation assumptions/risks and characterization of concrete mixtures to predict lateral pressure and to design vertical formwork safely and economically.

The contents of this course include four recorded presentations from the ACI 2023 Spring Convention.
1. Toronto 2013 Field Investigation to Support Prediction Models for SCC Formwork Pressure, by Kamal Khayat, Missouri S&T
2. Form Pressure Exerted by Self-Consolidating Concrete and Conventionally Vibrated Concrete. A Review of the New Document: ACI PRC-237-2.21, and Current Case Studies, by Stacia Van Zetten, EXACT Technology
3. Correlation of Lateral Formwork Pressure of Conventional Concrete—Using Methods Applied to the Development of SCC Lateral Pressure Models, by Eric Peterson, Webcor Builders
4. Current Pressure Models Presented in ACI 347, by Eric Eder, Ceco Concrete Construction

1. Compare the lateral pressure differences between self-consolidating and conventionally vibrated concrete (SCC and CVC) and how they may differ from full hydrostatic pressure.
2. Describe how the characterization of concrete mixtures, such as use of blended cements, changes in sand to coarse aggregate ratios, and use of set retardant admixtures, can affect lateral formwork pressure and decay rate of formwork pressure.
3. Discuss the principal factors affecting lateral formwork pressure from both (SCC and CVC) that are used in models to predict lateral pressures for columns and walls with different placement rates and heights.
4. Discuss how lateral pressure equations are affected by variable vibration and consolidation of concrete practices.

Study the materials included in this module. Then, complete and pass the corresponding 10-question quiz with a score of 80% or higher to receive a certificate for 0.1 CEU (1.0 PDH).
Continuing Education Credit: 0.15 CEU (1.5 PDH)
Approved by AIA and ICC
Access Period: 30 days