Oral Presentation

Volume Title: ICCE2021 Vol. 2

¹Ahmed Mohamed Rashwan ; ¹Kamal Abas Assaf; ²Yehia Abdel Azim Hassanean

¹Civil engineering department , Faculty of engineering , Assiut university

²Civil Department, Faculty of engineering, Assiut University

To develop a suitable self–consolidating concrete mix (SCC) with locally available materials, twenty (SCC) mixes in addition to three steel fiber reinforced self-consolidating concrete mixes (SFR-SCC) were evaluated by using The European Guidelines for Self Compacting Concrete Specification tests. The main studied parameters were sand/coarse aggregate ratio, the type and amount of chemical admixture dose and volume fraction of steel fibers. The test results showed that modified Polycarboxylates – based HRWRA met the requirements of flowability and segregation resistance than Naphthalin sulphonate – based HRWRA. Using crushed basalt was better for flowability than locally available rounded gravel. Also, it was noticed that finer sand is more satisfaction to flowability characteristics. Increasing sand/coarse aggregate up to 0.9 increased flowability with good segregation resistance. Adding Silica fume for both SCC and SFR-SCC mixes clearly improved the mixes flowability. Reducing water/cementitious ratio (W/C) to 0.35 was sufficient to maintain the flowability criteria. A volume fraction 1.25% of steel fibers met the requirements of fresh properties with good hardened properties. To practically test the efficiency of the proposed SFR-SCC mix in repairing purposes, two rectangular columns were tested under static axial load. One column was tested as control column and the other one was repaired with the suggested SFR-SCC mix. The ultimate load of repaired column increased by 150% compared to unrepaired column. The post-peak ductility of repaired column was significantly improved.

self-consolidating concrete; steel fiber-reinforced self-consolidating concrete; axially loaded columns