Abstract:
One of the most extensively utilized building materials in the world, concrete is used for
everything from roads and dams to buildings and bridges. Cement is one element which serves
as binder in concrete. Cement prices are rising daily in low-income countries like Ethiopia these
days. There are major environmental effects associated with the production of cement, however
attempts are being undertaken to mitigate these effects by using more sustainable production
techniques and alternative materials. The objective of this study was to examine how partially
replacing cement with TSA affect the mechanical properties and workability of concrete. Three
different mixes, each featuring a teff straw ash replacement of 0% to 15% in place of cement,
were developed for the C-25/30 grade of concrete, in addition to a control mix. Slump, a
measure of the fresh concrete's workability, was observed decreasing as the amount of TSA
increased. According to the test results, by day 28th, the concrete's compressive strength
increased by 6.2 % for TSA of 5%, 5.4% for TSA of 10%, and at TSA of 15% decreased by
7.05%. In regard to split tensile strength, the test result at 28th day indicates a 1.17% increase in
strength for TSA content of 5%, 0.29% for TSA content of 10%, and a 5.63% decrease in
strength for TSA content of 15%. Similarly, flexural strength test result at 28th days shows an
increase in strength by 3.48% for 5% of TSA, 6.82% for 10% of TSA and reduction in strength
14.15% for 15% of TSA. All percentage of TSA parabolic compressive Stress-strain curve at all
days of curing as like ES EN 1992’s code of standards. Therefore, it can said that replacing 5%
of cement TSA produce concrete with similar quality to the control test and it is the optimum
replacement.
