Recycled Steel Fiber on Environmental

¶ … Recycled Steel Fiber on Environmental Impacts of Concrete Application

The work of Wu, Lim and Li (1994) states that there has been much in the way of recent attention directed toward the United States in terms of its "rapidly deteriorating infrastructure." (p.1828) Stated as the main cause of the infrastructure decay is material deterioration with cracking behavior identified as the factor that is most important in determining durability and lifetime of concrete structures. The environmental factors that will be considered in concrete infrastructure sustainability include the factor of the increase in earthquakes in recent years. In addition to this is the consideration of climate change and factors that are related to those changes that will be considered in the research proposed herein. Concrete cracking behavior results from environmental strain which may include those stated as follows: (1) dry shrinkage; or (2) thermal change in concrete structures that have boundary conditions that are restrained. (Wu, Lim and Li, 1994, paraphrased) This type of shrinking/cracking behavior in paved concrete structures is common and most particularly for "large surface-to-volume ratio structures such as highway pavement, slabs for parking garages, and walls." (Wu, Lim and Li, 1994, p.1828)

The work of Vilkner, Meyer and Shimanovich states that the most important mechanical property of concrete is that of "compressive strength...because it correlates strongly with other properties such as tensile strength and many durability properties." (Date Unknown, p.5) It is additionally related by Vilkner, Meyer, and Shimanovich that the addition of fibers to a concrete mix is never for the purpose of additional strength and that the consideration of strength is only significant "...insofar as the addition of fibers should not reduce it below the value specified by the producer." (Date Unknown, p.5)

PURPOSE OF STUDY

The purpose of the study proposed herein is the examination of the effect of using recycled steel fiber on environmental impacts of concrete application.

RESEARCH QUESTIONS

The questions that will be addressed in the research proposed are those as follows:

(1) How does concrete contribute to global warming or in other words how sustainable is concrete?

(2) How important are the current trends in the use of concrete?

(3) What are the common mitigation methods used and how effective are these mitigations methods?

(4) How do fibers presently contribute to these methods and how could recycled fibers change these trends?

METHODOLOGY

The methodology proposed in this research is one of a qualitative nature in what will be an extensive review of the literature in this area of study. Because the studies reviewed will contain different measures and various factors that will be measured, this review will not report quantitatively but instead qualitatively and while quantitative research will be reported in this study as reported by other studies that the present study examines the findings in this study will be reported in a qualitative manner. Examined in this study will be factors such as the costs of the process of using recycled steel fiber in concrete and the methods used to recycle the fiber and this will be examined throughout the range of available literature in this subject area.

INITIAL REVIEW OF LITERATURE

The work of Vilkner, Meyer, and Shimanovich states in relation to adding fibers or other material to a concrete mixture that it is the increase of the "ductility and fracture toughness of an otherwise brittle material" that ultimately results in the reduction of concrete's compressive strength and furthermore the concrete mix experiences a reduction in its workability when large amounts of fiber are added and this results in difficulty in consolidating the concrete and in achieving a high-quality and low-porosity finished product.