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Full-Text Articles in Engineering
Quantifying Early-Age Concrete Mechanical Properties And Curing Conditions Utilizing An Automated System, Benjamin Arras
Quantifying Early-Age Concrete Mechanical Properties And Curing Conditions Utilizing An Automated System, Benjamin Arras
Open Access Theses & Dissertations
The validation of concrete quality based on the 28-day strength is a lengthy process. Predicting concrete mechanical properties through early-age methods can streamline the construction process. Early-age concrete behavior consists of assessing the concrete curing as-related to setting stages, the hydration process, strength and stiffness development, while considering various environmental system parameters. This paper reports on a nondestructive method for observing the early-age strength and modulus development of concrete mixes over seven days in a controlled, laboratory setting. An apparatus was designed and built for continuous acquisition of seismic modulus data (using free-free resonant column) and heat of hydration/maturity information …
Investigating Early Age Behavior Of Portland Cement Concrete In Arid Regions, Evan Wolf
Investigating Early Age Behavior Of Portland Cement Concrete In Arid Regions, Evan Wolf
Open Access Theses & Dissertations
The early-age behavior and properties of portland cement concrete change rapidly over time as a result of the hydration process. Comprised of a series of chemical reactions, this process accelerates nonlinearly with the curing temperature. Gaining knowledge and understanding of the phases of the hydration process (i.e., dormant, setting, and hardening) plays an important role in the timely opening of roads, resuming of construction, and achieving long-term performance. Standard tests such as ASTM C403 arbitrarily define the time of initial and final setting of concrete. Despite decades of studies concerning setting times, actual predictions still span hours, while the quality …
Studying The Parameters Involved With Modulus-Based Construction Quality Control For Compaction Of Unbound Pavement Layers, Mehran Mazari
Studying The Parameters Involved With Modulus-Based Construction Quality Control For Compaction Of Unbound Pavement Layers, Mehran Mazari
Open Access Theses & Dissertations
Pavement performance is impacted by several factors such as the properties of the materials, combination of traffic and loading, structural capability, climate changes and construction process. Earthwork and unbound materials is an important part of pavement constructions since most of the distresses can be related to these geomaterials. Appropriate process control, proper processing of geomaterials, adequate amount of moisture and suitable compaction effort would ensure the required density and stiffness of the compacted pavement layer. The Nuclear Density Gauge (NDG) has been the primary means of Quality Control and Quality Acceptance (QC/QA) by State Highway Agencies (SHAs) and department of …
Impact Of Moisture Content And Density On Stiffness-Based Acceptance Of Geomaterials, Lourdes Guadalupe Pacheco
Impact Of Moisture Content And Density On Stiffness-Based Acceptance Of Geomaterials, Lourdes Guadalupe Pacheco
Open Access Theses & Dissertations
Modulus-based quality management of compacted layers has been considered by a number of highway agencies. Even though simple in concept, the paradigm shift from density to modulus for quality acceptance has generated some technical and institutional challenges. One of these complications is that for a given density, the modulus can vastly vary depending on the moisture content at the time of compaction and at the time of acceptance. The results of a systematic study carried out to qualify and quantify the impact of compaction moisture content, moisture content at the time of field testing and density on the modulus and …