The main objective of this study is to investigate drying properties and plastic shrinkage cracking resistance of fresh cement-based pastes reinforced with fibers and textiles. Naturally occurring mineral wollastonite has been studied independently as well as in combination with AR-glass textile. A series of blended mixes with Portland cement and…
The main objective of this study is to investigate drying properties and plastic shrinkage cracking resistance of fresh cement-based pastes reinforced with fibers and textiles. Naturally occurring mineral wollastonite has been studied independently as well as in combination with AR-glass textile. A series of blended mixes with Portland cement and wollastonite nano-fibers were developed and tested under low vacuum conditions to simulate severe evaporation conditions and expedite the drying process causing plastic shrinkage cracks. Cumulative moisture loss, evaporation rates, and diffusivity were analyzed by means of a 2-stage diffusion simulation approach, developed previously in Arizona State University. Effect of fiber-matrix interaction on the transport properties of the composite were evaluated using the existing approach. Morphology of the cracked surface was investigated by the means of image analysis wherein length, width, area and density of the cracks were computed to help characterize the contribution of fiber and textile in the cracking phenomenon. Additionally, correlation between cumulative moisture loss and crack propagation was attempted. The testing procedures and associated analytical methods were applied to evaluate effectiveness of four wollastonite fiber sizes and also a hybrid reinforcement system with alkali-resistant glass (ARG) textile in improving shrinkage cracking related parameters. Furthermore, the experimental and analytical approach was extended to magnified version of the existing shrinkage testing set-up to study the size effect of these composites when subjected to matching drying conditions. Different restraining mechanisms were used to study the simulation of the cracking phenomena on a larger specimen. Paste and mortar formulations were developed to investigate size effect on shrinkage resistance of cementitious composites.
The once thriving American textile industry has been offshored almost entirely. The few domestic mills that remain tend to be specialized; there is no dominant player. As the global environment becomes increasingly unpredictable, the benefits of offshoring are lessening. Raising concerns over sustainability, employee welfare and intellectual property have the…
The once thriving American textile industry has been offshored almost entirely. The few domestic mills that remain tend to be specialized; there is no dominant player. As the global environment becomes increasingly unpredictable, the benefits of offshoring are lessening. Raising concerns over sustainability, employee welfare and intellectual property have the potential to shift the current pattern of offshoring. Impulsive tariffs and rising international wages add to the uncertainty. To eliminate many of these concerns, new textile mills should be developed in the United States. Many businesses have expressed desire and need for a new American mill to help them meet their goals. Due to strict regulations, domestic production is inherently more environmentally and socially proactive. In order for this mill to succeed, it must be based on automation and sustainable practices.
