Browsing by Author "Abu Hasan"

Now showing 1 - 2 of 2

Influence of Steel Fiber and Superplasticizer on Crumb Rubberized Concrete
(2024-12-15) Abu Hasan; Asadul Howlader, Md.; Ahmed, Redown; Saon, Hasibul Islam
In recent years, the substantial disposal of a large volume of scrap tires has posed a significant environmental solid waste problem. Crumb rubber (CR) generated from these waste tires can serve as a partial replacement of normal aggregates to make crumb rubberized concrete (CRC). Therefore, to investigate the properties of CRC, CR was used as 5%, 10%, and 15% replacement of sand in this study. In addition, steel fiber (SF) by 1% volume fraction of concrete and superplasticizer (SP) by 1% weight of cement were added individually to compare the improvement of concrete strength. Slump, unit weight, compressive strength, and split tensile strength tests were conducted to investigate and compare the properties of CRC. The experimental findings revealed that, as the amount of SF increased, unit weight, compressive strength, and split tensile strength increased. However, SP showed a greater improvement in CRC than SF. The addition of SF increases the compressive strength approximately from 11% to 16% and split tensile strength from 7.6% to 16.3%, while SP showed an increase from 21.1% to 24.5% and 12% to 25%, respectively. Therefore, it can be stated that the 1% SP has better strength improvement quality in comparison with 1% SF.
Mechanical properties of concrete using crumb rubber and human hair fiber
(2024-03-03) Abu Hasan; Masud Rana, Mohammad; Khan, Riyaj Mahamud
Nowadays, an enormous amount of scrap tires being disposed of causes severe environmental solid waste concerns. According to previous research, these waste tires can partially replace normal aggregates to make crumb rubberized concrete (CRC). Human hair (HH) has also been found in different research as a beneficial component in concrete. In this study, crumb rubber (CR) was used as a fine aggregate substituting sand by 5%, 10%, and 15%, and HH was utilized as a fiber in amounts of 1%, 2%, and 3% by weight of cement in the concrete mix. According to the test results, workability was improved, but density was reduced by adding CR and human hair fiber (HHF) to the concrete mix. In addition, compressive strength decreased from 6.23% to 21.85%, and splitting tensile strength decreased from 17% to 33% compared to the normal concrete with increasing percentages of CR from 5% to 15%. In contrast, these strengths improved by 13.23% when 1% HHF was used in the normal concrete mix, but a decreasing trend was observed for more than 1% of HHF. A good improvement of 3.6% in compressive strength and 8.56% in splitting tensile strength was found for a combination of 5% CR and 1% HHF in the concrete mix compared to the normal concrete. However, all other combinations resulted in a loss in these qualities.