Engineering Commons^™

Machine Learning Prediction Of Mechanical And Durability Properties Of Recycled Aggregates Concrete, Itzel Rosalia Nunez Vargas

Electronic Thesis and Dissertation Repository

Whilst recycled aggregate (RA) can alleviate the environmental footprint of concrete production and the landfilling of colossal amounts of demolition waste, there need for robust predictive tools for its effects on mechanical and durability properties. In this thesis, state-of-the-art machine learning (ML) models were deployed to predict properties of recycled aggregate concrete (RAC). A systematic review was performed to analyze pertinent ML techniques previously applied in the concrete technology field. Accordingly, three different ML methods were selected to determine the compressive strength of RAC and perform mixture proportioning optimization. Furthermore, a gradient boosting regression tree was used to study the …

Investigation Of Grouted Dowel Connection For Precast Concrete Wall Construction, Douglas J. Provost-Smith

Electronic Thesis and Dissertation Repository

The grouted dowel connection is a simple and cost-effective connection used in many precast concrete structural systems. The required dowel length is currently designed as a regular bar in reinforced concrete, which underestimates the bond strength, thus resulting in excessive connection lengths. Furthermore, precast wall construction continues throughout cold weather, where in-situ heating of the grout used in the grouted dowel connections is usually conducted for short periods of time. Hence, early-age exposure to subfreezing conditions may affect the quality of the grout and subsequently the bond strength of the connection, which can compromise structural integrity.

In this thesis, full-scale …