Q2. What is the author’s opinion on the use of a wide range of available data?
The authors’ opinion is that the use of a widest range of available data, such as the collected database, may be useful for re-calibration previously developed analytical formulations that will lead to simple, cost-effective, design guidelines suitable for design practice.
Q3. What was the purpose of the analysis?
Aiming to reduce the influence of erroneous and inconsistent data present in the DB, even after the pre-trial operation, the analysis was performed not only in the integral database (IDB), but also in partial subsets of the data - reduced databases (RDB).
Q4. What is the way to strengthen a beam?
For elements with shear resistance deficiencies, a higher load carrying capacity may be achieved by bonding FRP reinforcement systems with the fibers as orthogonal as practically possible to the critical shear crack plane for an optimal configuration, or with the fibers normal to the beam axis for a more practical setting.
Q5. What was the used system for the testing of RC beams?
From the collected data it was found that the vast majority of the tests (≈83 %)were conducted with rectangular cross sections (R), with an average height of around 350 mm, where 54 % of the tested beams had a concrete compressive strength between 20 and 30 MPa,and the most used strengthening system was type U (≈50 %).
Q6. What is the impact of some parameters on the design models?
The influence of some parameters not explicitly considered on the analytical models was assessed, proving that the performance of the aforementioned design models is subordinate to the global attained shear force gain.
Q7. How many beams did the researchers test?
It is also noticeable thatapproximately 51 % of the tested beams did not have any shear reinforcement at all, and all of them had a large longitudinal reinforcement ratio, ρsl, with a mean value of about 3 %.
Q8. What is the popular method of strengthening RC beams?
FRP shear reinforcement of RC beams has been widely studied in the last decade with a large number of scientific publications exalting the effectiveness of this strengthening technique.
Q9. What were the results of the tests used in the calibration of the aforementioned formulations?
A significant number of test results, which were used in the calibration of several analytical formulations, were obtained with unrealistic geometric conditions and reinforcement settings.
Q10. What is the effect of the interaction between FRP and conventional steel reinforcement?
From these studies one can establish that this interaction significantly decreases the performance of externally bonded FRP strengthening technique, which, in the opinion of the authors, indicates that this influence should be explicitly considered in the analyticalbased on the assumption that the superimposition principle, = r c s f V V V V+ + , is applicable,admitting, therefore, that the FRP strengthening system does not interfere with the contribution of the Vc and Vs items, determined independently and summed.
Q11. What is the effect of sl on the prediction of Vfd?
Despite the fact that none of the design models explicitly consider the influence of ρsl in the prediction of Vfd, the attained results reveal that such parameter should not be neglected, with a general trend for higher χ ratios with the increase ofρsl.