Entrained Air-Void System For Durable Highway Concrete

In the US, the most commonly used F-T test method is AASHTO T 161 “A.” The equipment for variant A of the test is relatively low cost (~$22, 000) and compact. The relatively low cost stems from the basic construction of a refrigerant-based cooling system and resistive heating elements. These units are easily repaired by conventionally trained heating and air conditioning technicians and economically modified using readily available controls. Consequently, proposed factors and modifications to the test method are based on this piece of equipment. Sufficient background information exists in the research literature and current global applications to recommend improvements/modifications to the F-T test method, such as changes to the cooling rate, degree of saturation, and sample conditioning method. Based on an analysis of significant factors reported in the literature, in this study, a series of procedural and functional changes were proposed to better describe F-T durability as a function of the air void system. These changes include: 1- Procedural modifications including longer curing times to better encompass requirements for higher SCM mixtures and the introduction of a drying period to better simulate actual field exposure conditions, 2- Functional modifications including introducing water through capillary suction and changing the freezing solution to incorporate deicing salts, 3- A combination of modification approaches including application of a concentrated pre-storm brine followed by drying.The F-T research was performed in three phases. The first phase involved calibration and modification of the AASHTO T 161 “A” freeze-thaw cabinet using the proposed CDF-A procedure. A modification procedure was developed, and an appendix to the final report was described the steps taken to achieve the desired test requirements. The second phase involved evaluating three separate variants of the proposed test not encompassed by current test methods including the impact of curing time, deicer type, and deicer pretreatment. The third phase involved evaluating a wide range of concrete samples with varying levels and qualities of air systems.

Name thesis:degree_name

Ph.D. (Doctor of Philosophy)

Level thesis:degree_level

Ph.D.

Discipline thesis:degree_discipline

Engineering (UMKC)

Grantor

University of Missouri--Kansas City

Year dc:date.issued

2020

Author dc:creator

• Riyazi, Siamak

Advisor dc:contributor.advisor

• Kevern, John T.

Handle dc:identifier.uri

https://hdl.handle.net/10355/73313

OAI identifier oai:identifier

oai:mospace.umsystem.edu:10355/73313