Asa, E; Shrestha, M; Baffoe-Twum, E and Awuku, B (2020) Development of sustainable construction material from fly ash Class C. Journal of Engineering, Design and Technology, 18(6), pp. 1615-1640. ISSN 1726-0531
Abstract
Purpose: Environmental issues caused by the production of Portland cement have led to it being replaced by waste materials such as fly ash, which is more economical and safer for the environment. Also, fly ash is a material with sustainable properties. Therefore, this paper aims to focus on the development of sustainable construction materials using 100% high-calcium fly ash and potassium hydroxide (KOH)-based alkaline solution and study the engineering properties of the resulting fly ash-based geopolymer concrete. Laboratory tests were conducted to determine the mechanical properties of the geopolymer concrete such as compressive strength, flexural strength, curing time and slump. In phase I of the study, carbon nanotubes (CNTs) were added to determine their effect on the strength of the geopolymer mortar. The results derived from the experiments indicate that mortar and concrete made with 100% fly ash C require an alkaline solution to produce similar (comparable) strength characteristics as Portland cement concrete. However, it was determined that increasing the amount of KOH generates a considerable amount of heat causing the concrete to cure too quickly; therefore, it is notable to forming a proper bond was unable to form a stronger bond. This study also determined that the addition of CNTs to the mix makes the geopolymer concrete tougher than the traditional concrete without CNT. Design/methodology/approach: Tests were conducted to determine properties of the geopolymer concrete such as compressive strength, flexural strength, curing time and slump. In Phase I of the study, CNTs were studied to determine their effect on the strength of the geopolymer mortar. Findings: The results derived from the experiments indicate that mortar and concrete made with 100% fly ash C require an alkaline solution to produce the same strength characteristics as Portland cement concrete. However, it was determined that increasing the amount of KOH generates too much heat causing the concrete to cure too quickly; therefore, it is notable to forming a proper bond. This study also determined that the addition of CNTs to the mix makes the concrete tougher than concrete without CNT. Originality/value: This study was conducted at the construction engineering and management concrete laboratory at North Dakota State University in Fargo, North Dakota. All the experiments were conducted and analyzed by the authors.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | carbon nanotubes; compressive and flexural strength; fly ash; geopolymer; slump |
| Index terms: | flexural strength, mortars (material), waste material, geopolymer concrete, fly ash, construction engineering, mechanical property, compressive strength, experiment, carbon nanotube, laboratory, environmental issue, sustainable construction, methodology, curing |
| Subjects: | data collection methods, materials science, environmental issues, building materials, environmental science, engineering methods, research methods, material analysis and testing, specialized materials and systems, structural engineering, concrete and cementitious materials, sustainable construction, material properties and characteristics, research management |
| Topics: | Construction Materials, Engineering Principles, Research Practice, Sustainability |
| Descriptive scope: | 4 PCTE |
N.B. Descriptive scope is a count of how many of the five facets of empirical research are indicated by the words used in title, abstract and keywords. It is not intended as a judgement on the research; merely a count of the kind of word we would expect to indicate Phenomenon, Concepts, Theoretical framing, Empirical techniques, Analytical techniques. If all five are present, then a code of “5 PCTEA” will indicate this. If you feel the coding for this record is questionable, we welcome discussion around the terms we matched or the way we categorized them. The facet you would expect may not be coded, or a facet may be coded inappropriately. This can also bear on a larger question, of which facets should be treated as defining in construction management research. Please get in touch, and we will look at it. More details here