This research program focuses on investigating the shear resistance, bond characteristics, and corrosion performance of self-consolidating concrete (SCC) compared to those of normal concrete (NC). The shear strength, cracking behavior, and deflection characteristics were tested in full-scale beams. A total of twenty reinforced concrete beams, with no shear reinforcements, were tested under mid-span concentrated load until shear failure occurred.

The experimental test parameters included concrete type/coarse aggregate content, beam depth and the longitudinal reinforcing steel ratio (ρ_w). The beam depth ranged from 150 to 750 mm while the shear span-to-depth ratio (a/d) was kept constant in all beams, The two longitudinal reinforcing steel ratios used were 1% and 2%.

The performance of SCC/NC beams was evaluated based on the results of crack pattern, crack widths, loads at the first flexure/diagonal cracking, ultimate shear resistance, post-cracking shear resistance/ductility, load-deflection response, and failure modes. Code-based equations or procedures are used to predict the crack width, first flexural cracking moment/load, and ultimate shear resistance as well as to simulate load-deflection response.

The bond strength of reinforcing bars embedded in full-scale heavy reinforcing beams (4000 mm length x 1200 mm depth x 300 mm width) made with SCC was investigated and compared with that of NC. The flowability of SCC mixture through the dense reinforcement was visually monitored from a transparent formwork.

The bond stress was tested for bars located at three different heights (150 mm, 510 mm, and 870 mm from the bottom of the beam) and at different concrete ages (1, 3, 7, 14 and 28 days). The bond stress-free end slip relationship, the top bar effect, and the effect of age on bond stress were investigated in both SCC and NC beams. Bond stresses predicted based on some major Codes were compared with those obtained from experiments. The corrosion of steel reinforcement embedded in full-scale SCC beams was investigated and compared to that embedded in NC beams.

The corrosion performance of 400 mm width x 363 mm depth x 2340 mm length beams containing epoxy and non-epoxy coated stirrups was monitored by partial immersion in a sodium chloride solution and an impressed current. Half-cell potential tests were implemented at 25 different locations on each beam to evaluate the probability of steel corrosion along the beam length/perimeter.

At the same locations where the half-cell potential tests were implemented, the chloride ion content near the bar surface was measured to study the variation of the chloride-ion penetrability along the beam length/perimeter. The mass loss and bar diameter degradation along the length of each bar were investigated at the end of the test. Predicted rebar mass loss due to corrosion based on Faraday’s law was compared with experimental mass loss for each beam.

Small-scale cylinder specimens made of NC and SCC with centrally located embedded reinforcing bar was also tested to investigate the effect of segregation and bleeding on corrosion performance. The corrosion performance of various SCC with different types of high range water reducers (HRWRs) were also investigated with small-scale cylinder specimens.

The structural performance and cracking behavior of full-scale corroded reinforced concrete beams made with SCC was investigated and compared with those of NC. Six reinforced concrete beams (2340 mm length x 363 mm depth x 400 mm width) without web reinforcement designed to fail in shear were tested under mid-span concentrated load after three degrees of corrosion obtained (0, 8%, and 25% degree of corrosion). The performance of corroded SCC/NC beams was evaluated based on the results of crack patterns, crack widths, loads at the flrst flexure and frrst diagonal cracks, mid span deflection, ultimate load, and failure modes. In addition, the results of the crack widths and the mid-span deflections were compared with some major Code-based equations.

Based on the results of the shear strength investigation, the ultimate shear strength of SCC beams was found to be slightly lower than that of NC beams. The difference was more pronounced with the reduction of longitudinal steel reinforcement and with the increase of beam depth. However, the results of testing the bond strength in heavily reinforced beams indicated that casting sec beam was faster, easier, required less labor, and did not result in blockage of concrete among the heavy reinforcements when compared with NC. The results of the bond strength also indicated that the bond stress was slightly higher in SCC beam compared with NC beams and the difference was more pronounced in the top bars and at 28 days of testing.

The results of the corrosion investigation showed that SCC beams had superior performance compared to their NC counterparts in terms of cotTosion cracking, corrosion rate, half-cell potential, time of con·osion initiation, rebar mass loss and rebar diameter reduction. The sec beams showed severe localized corrosion of stirrups and longitudinal rebars at the far end of the beam (away from the casting point). The SCC beams also had spalling of concrete cover at the comers due to inadequate local compaction and distribution of concrete. A strong correlation between the predicted rebar mass loss (using Faraday's law) and actual rebar mass loss, due to corrosion, validates the use of theoretical estimates to examine the effect of corrosion over time. The difference between SCC and NC mixtures in terms of corrosion was only pronounced in large-scale beams and types of HR WR have no influence on corrosion performance.