Global Journal of Researches in Engineering, A: Mechanical & Mechanics, Volume 22 Issue 1

Construction of Concrete Wall with Resistance to Explosions- A View © 2022 Global Journals Global Journal of Researches in Engineering (A ) Volume XxXII Issue I Version I 42 Year 2022 V. R esult of F ield A pplications The primary thing is that the slump and Slump flow results are taken. The fluidity of the concrete mixture was raised after the pumping. In general workability of concrete is decreased in slump or flow after the pumping. In this research however the fiber reinforced concrete is throughout the fiber in concrete mixer was adjusted by the pressure of the pumping and it provided the improved fluidity of the fiber reinforced concrete mixture. In spite of increases fluidity of the mixture, air content of concrete was decreased. It is similar trend of already reported results of studies. However, in general, the properties of fresh-state fiber-reinforced concrete mixture were acceptable to use field construction, and there was no problem on placing process of the wall. The field-processed HPFRCC’s mechanical properties were evaluated with compressive strength. All concrete samples showed over 30 MPa and it absolutely was above the target compressive strength of 25 MPa. For the concrete mixture obtained after the pumping, slightly increased compressive strength was observed. It should be stated that decreased air content and well- oriented fiber can contribute to the improved compressive strength. For more detail, although it’s a necessity to review the relation between pumping and performance of HPFRCC, during this research, the goal of the experiment was evaluating field applicability of HPFRCC, thus it is not discussed during this paper. In this research with a goal of applying HPFRCC on field conditions, the workability, mechanical properties, and protecting performance of combined fiber-reinforced concrete mixtures were evaluated, and field application was conducted with a ready-mixed concrete system. Per a series of experiment, some conclusions are obtained as follows: 1) By using combined fiber of SF and PF, fresh-state properties of HPFRCC were improved rather than the case with the unfavourable result with one fiber and showed better performances than the averaged value of each single-type fiber-reinforced mixture. VI. C onclusion Safe design of RCC wall is done by either increasing the thickness of wall or by increasing the share of steel. Just in case where there’s restriction of space, such the wall thickness has been restricted it’s desirable to increase the share of steel because it winds up in safer design from ductility point of view but should accommodates the minimum percentage of steel. This might cause cost effectiveness of RCC wall. It has been found that for a 200mm thick RCC wall, minimum percentage of steel required to resist blast loading is 0.75%. For a 250mm thick RCC wall, percentage of steel required to resist blast loading is 0.40%. For a 300mm, thick RCC wall percentage of steel required to resist blast loading is 0.25%. 2) For mechanical properties of compressive, flexural, and tensile strengths, the mixture with combined fiber showed improved values rather than any single-type fiber-reinforced mixtures. 3) Regarding the protection performance against flying debris, the HPFRCC panel reinforced by combined fiber showed the foremost desirable performance of protecting the high-velocity projectile. 4) The combined HPFRCC showed improved mechanical and protecting performances with favourable workability. Supported these improved features of combined fiber reinforcement, field application of combined HPFRCC was successful under the ready-mixed concrete system including agitators, delivering, and placing. R eferences R éférences R eferencias 1. P. R. Tadepalli, Y. L. Mo, T. T. Hsu, and J. Vogel, “Mechanical properties of steel fiber reinforced concrete beams,” in Proceedings of Structures Congress 2009: Don’t Mess with Structural Engineers: Expanding Our Role, pp. 1-10, 2009. 2. Z. Bayasi, “Development and mechanical characterization of carbon fiber reinforced cement composites and mechanical properties and structural applications of steel fiber reinforced concrete,” Ph.D. dissertation, vol. 1, pp. 1 199, Michigan State University, 1989.