Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Reactive powder concrete


Direct Shear Strength of RPC Member

Shahad Q. Madhlom; Hussein A. Aziz; Ammar A. Ali

Engineering and Technology Journal, 2021, Volume 39, Issue 1A, Pages 22-33
DOI: 10.30684/etj.v39i1A.1638

In this research paper, results are obtained from Reactive Powder Concrete (RPC) push-off specimens - double L shape subjected to direct shear loading. Different parameters considered are compressive strength, percentages of steel fiber, presence of aggregate and shear reinforcement. The results show that increasing in steel fiber content starting from 0.0% and ending with 1.5% leads to increases in the shear strength by (261%) and attempt to decrease its brittleness. The presence of steel fiber content enhances and improves the tensile strength and the shear strength. Using RPC in constructing the specimens enhances the shear strength by 29.6% compared with NSC specimen.
Shear strength increased by 25% when the compressive strength increased from 75 to 90MPa. The presence of transverse steel rebar in the direction of shear line increased the shear strength by (108.3%) as compare with the specimen without shear rebar. The presence of small aggregate in RPC mix creates an increase in the shear strength by (9.1%).

The Influence of Shear Strain on the Torsion Capacity of Hybrid Beams

Alyaa H. Mohammed; Kaiss F. Sarsam; Qais A. Hasan

Engineering and Technology Journal, 2020, Volume 38, Issue 7, Pages 951-959
DOI: 10.30684/etj.v38i7A.371

This research discusses experimentally the shear strain of the reinforcement concrete hybrid beams composed of reactive powder concrete (RPC) at the peripheral and conventional concrete (CC) at the core beams under torsional strength tests. Shear strain is usually represented by is explained as the tangent of the angle and is be like the length of deformation at its maximum divided by the length of perpendicular in the plane of the force application. Twelve reinforced concrete beams are tested having the following dimensions: 100, 200 and 1500mm as width, height and length respectively with thickness of the RPC concrete were 40 and 20mm. The beams were cast and tested to failure in torsion by using two opposite cantilevers steel arms that contribute to transferring the torque to the centre of the beams. Two control (CC and RPC) beams were poured, and the ten other beams were all poured as hybrid ones. Experimental data of the three strain gauges locations in the middle of the beams in one of the side surface face, to calculate shear strain (). The percentage of shear strain at ultimate torsion capacity was reduced by about 76% for RPC (RP) to CC (NC) beams and 63% for hybrid beam (H1) to CC (NC) beam.

Numerical Study of Bond Stress-Slip Relationship in Large Scale Reactive Powder Concrete Beams

Eyad K. Sayhood; Sameh B. Tobeia; Ammar A. Ali

Engineering and Technology Journal, 2019, Volume 37, Issue 12A, Pages 496-505
DOI: 10.30684/etj.37.12A.1

As the reactive powder concrete (RPC) represents one of the ultra-high performance concrete types that recently used in public works and in the presence of several attempts that aims to examine the behavior of RPC, this work aims to theoretically study the bond stress between RPC and steel bars and the corresponding slip for large reactive powder concrete beams by using finite element models done by ANSYS 16.1 software. Where, these numerical models were verified through several comparisons between their results, and the experimental one from previous work, in which good agreement were achieved. The effects of several parameters on the bond stress were studied, the parameters include concrete compressive strength, and steel fibers content, bar diameter, length of the developed bar and concrete cover thickness.

Influence of Steel Fiber and Spacing of Stirrups on the Torsion Capacity of Hybrid Beams

Alyaa H. Mohammed; Qais A. Hasan; Kaiss F. Sarsam

Engineering and Technology Journal, 2019, Volume 37, Issue 12A, Pages 506-511
DOI: 10.30684/etj.37.12A.2

This paper investigates experimentally the torsional behaviour of hybrid reinforced concrete beams composed of reactive powder concrete (RPC) at the outer edges of the cross-section and conventional concrete (CC) at the inner parts of the cross-section. Hybrid reinforced concrete members are used extensively to deal with the members strength requirements related to flexural, shear and torsion in structural systems. The torsion failure is undesirable because of its brittle nature, it is obligatory to avoid this kind of failure in the earthquake areas. Seven reinforced concrete beams, with dimensions (100X200X1500 mm), the interior dimensions of hybrid beams of the cross-sectional area (20mm width and 120mm height) with 1500 mm length were cast and tested to failure using two opposite cantilevers steel arms that contribute to transferring the torque to the centre of the beam. The first beam was RPC, the second beam was CC and the other five beams were all poured as hybrid ones. Experimental data of the ultimate capacity, cracking torsional loads, the failure pattern and twisting angle for each beam were gained. Experimental results showed higher value of ultimate torsional strength of hybrid beams than CC ones by about (50) % and lower than reactive powder concrete specimen by about (16.67) % for both varying steel fibre and spacing of stirrups.