The eco-friendly alternatives use is increasing momentum in a conscious effort
towards sustainability. In this regards, the relevance and the economic value of
using copper slag as a concrete aggregate are explored in this study in order to
contribute towards metallurgical waste recycling. Emphasis is placed on the
evaluation of the concretes strengthening prepared with copper slag contents and
produced under four curing methods: water immersion, water spraying, plastic
sheet covering and air-drying. In each curing case excluding for water immersion,
was duplicated in indoors (i.e. in the laboratory) and outdoor exposure (so was
prone to varying environmental conditions). This was specifically aimed at
capturing the effects of tropical weather conditions typical of the Lualaba province
in the Democratic Republic of Congo.
The control mix was designed to reach 25 MPa of compressive strength. Copper
slag was successively incorporated as sand replacement at the following mass
fractions: 20 %, 40 % and 60 %. Freshly mixed concrete samples were evaluated
for workability. Cube specimens were cast accordingly, cured for 28 days and then
tested for density and compressive strength.
Results indicated an increase in strength up to 20 % of replacement rate for all the
curing methods. Further additions resulted in reduction in the strength, but the rate
of reduction depended on curing conditions. The increase in strength was mainly
credited to the physical properties of copper slag that could have contributed to the
cohesion of the concrete matrix. It has been found that appropriate ways of curing
can still achieve greater results than that of the control mix since 80 % of humidity
is ensure. The two-way ANOVA test performed on the 28-days compressive
strength values confirmed the significant influence of the curing methods, of copper
slag content and the interaction between them. It has been found that considerable
influence is attributed to copper slag content and that warm environmental
conditions further extend the concrete strengthening. / College of Engineering, Science and Technology / M. Tech. (Chemical Engineering)
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:unisa/oai:uir.unisa.ac.za:10500/26694 |
| Date | 10 1900 |
| Creators | Kyalika, Cynthia Mumeka |
| Contributors | Mulenga, Francois |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Dissertation |
| Format | 1 online resource (xvi, 131 leaves) : color illustrations. graphs (chiefly color), application/pdf |
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