Degree Type

Thesis

Date of Award

2012

Degree Name

Master of Science

Department

Civil, Construction, and Environmental Engineering

First Advisor

Chales T. Jahren

Second Advisor

Fouad S. Fanous

Abstract

The construction of mass concrete elements poses several risks with regard to thermal damage, which results from the thermal characteristic and size of mass concrete elements. If the heat of hydration generated in mass concrete is not controlled or dissipated properly, thermal damage may result by means of thermal cracking and/or delayed ettringite formation.

The objectives of the present research are: (1) to have an understanding of how different mix proportions, construction, and environmental conditions affect the thermal development of mass concrete. (2) To identify and compare the similarities and differences of mass concrete specifications for different agencies throughout the United States. (3) To explore a tool for effectively analyzing temperature development and cracking potential of mass concrete. (4) Provide rational recommendations for improving current mass concrete specifications.

In this study, a literature and specification survey was conducted to determine typical construction practices, and to identify conditions that typically have the largest effect on the thermal development of mass concrete. A case study was developed for two typical Midwest boarder bridges, and was utilized to calibrate and verify ConcreteWorks. ConcreteWorks is a concrete thermal analysis software program, capable of predicting the early age thermal behavior of mass concrete. ConcreteWorks was then utilized to validate conditions that are believed to have the largest effect on the thermal development of mass concrete.

The research also provides two case studies of typical Midwest boarder bridges that may be used to calibrate other thermal analysis software programs. Through the sensitivity study, the research also verifies conditions that have the largest effect on the thermal development of mass concrete for Midwest boarder bridges.

The research determined: (1) How different mix proportion, construction, and environmental conditions affect the thermal development of mass concrete. (2) There is little consistency between mass concrete specifications between state agencies. (3) ConcreteWorks is capable of effectively analyzing the temperature development and cracking potential of mass concrete elements. (4) Performance based specifications should be utilized to allow contractors more flexibility in the design of the construction of mass concrete placements. Furthermore, additional specification requirements should be implemented for the thermal monitoring of mass concrete elements to assure accurate temperature readings.

This research contributes to the current knowledge of mass concrete by providing recommendations for specification improvement.

Copyright Owner

Jacob Joseph Shaw

Language

en

File Format

application/pdf

File Size

208 pages

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